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Home My WebLink AboutCOUNCIL - AGENDA ITEM - 10/29/2013 - WEST NILE VIRUS MANAGEMENT POLICY AND RESPONSE PLADATE: October 29, 2013 STAFF: Mike Calhoon, Kelly DiMartino, Dan Weinheimer Pre-taped staff presentation: available at fcgov.com/clerk/agendas.php WORK SESSION ITEM FORT COLLINS CITY COUNCIL SUBJECT FOR DISCUSSION West Nile Virus Management Policy and Response Plan Review. EXECUTIVE SUMMARY The purpose of this discussion is to review the activities from the 2013 West Nile season and gather initial Council input regarding the Program Response Guidelines review that will occur this winter/spring. The City’s West Nile Virus (WNV) Management Policy was adopted July 1, 2008 and the Policy and Program Response Guidelines were last updated in March 2013. The latter part of the summer of 2013 was a challenging and quickly evolving period for West Nile virus activity. Despite larval control efforts, the risk of West Nile virus was deemed extremely high and the Larimer County Department of Health and Environment made a formal recommendation to perform adult mosquito control (adulticiding). The recommendation was considered per the Policy and Program Response Guidelines, and adulticiding occurred on August 14/15 and August 19/20. GENERAL DIRECTION SOUGHT AND SPECIFIC QUESTIONS TO BE ANSWERED 1. What is working well with the existing WNV Policy and Program Response Guidelines and what areas need to be improved? 2. Does Council concur with the proposed review process? Are there any adjustments Council would like to see? BACKGROUND / DISCUSSION West Nile virus first appeared in Colorado in 2002 and became a concern in the Fort Collins community in 2003. Since that time, the City has established a Council-adopted policy (Attachment 1) and a set of mosquito management operating protocols to reduce the risk of infection from West Nile virus. Using a “plan, do, check, act” approach, the City has continually evaluated and incorporated data and best practices from public health entities and other communities into the protocols. In 2007, the City Manager directed formation of a Technical Advisory Committee (TAC) to assist in reviewing the practices, procedures and risks of a mitigation policy. The work of the TAC resulted in recommendations which formed the 2008 West Nile Virus Program Response Guidelines. The TAC is an eight person team (excluding staff and contractor) comprised of individuals with diverse perspectives, ranging from content experts to concerned citizens. The TAC typically meets at least twice per year to review the season’s activity, to review new products and procedures for controlling mosquitoes, and to suggest changes for the upcoming season. Following a review completed in winter 2012 through spring 2013, the West Nile Virus Program Response Guidelines were updated to make the following improvements: October 29, 2013 Page 2  Reinstate the backyard inspection program  Reinstate the stormwater inspection program  Expand communication efforts, including door hangers and better coordination with Poudre School District and Colorado State University  Provide more stringent criteria before adulticiding occurs (increase the Vector Index from 0.5 to 0.75). These adjustments were reviewed by City Council in March 2013. Existing Integrated Pest Management Plan The City has developed a broad-based preventative program that includes public education and information, adult and larval mosquito population monitoring, and larval control. The City’s policy allows for adult mosquito control (adulticiding) after pre-determined conditions are met. These conditions are listed in the Program Response Plan Guidelines (Attachment 2). The City retains a licensed mosquito control contractor to provide technical services, including larviciding and trapping. Testing is conducted by a separate agency, Colorado State University. The licensed contractor also conducts truck-based spraying/adulticiding when necessary. Since implementation of the Program Response Guidelines in 2008, the City has adulticided part of the community in 2012 and the entire community 2013. Review Process The summer 2013 adulticiding application creates an ideal opportunity to review the Program Response Guidelines related to adult mosquito control. Based on an initial staff review, as well as public and Council comments, following is a summary of areas that went well and areas that could be improved: Areas that went well  Clear response guidelines in place to guide decision-making  Application of adulticide completed on schedule in four evenings, avoiding the New West Fest weekend  Good coordination with Poudre School District and Colorado State University regarding schedules and communication  The application successfully avoided properties on the Pesticide Sensitive Registry  The Risk Index was at 0.85 pre-spray and was reduced to 0.25 post-spray  Effective outreach re: media relations, social media, and door hangers in some areas. Areas for improvement  Non-emergency phone notification system does not effectively reach broad population  Truck-tracking system was released prematurely without adequate testing time and did not function as hoped; had to use a back-up approach  Further opportunities to expand and enhance existing education programs  Better coordinate with homeowner associations who have contracted for spraying  Enhanced communication and coordination with key stakeholders, including organic farmers and beekeepers. A season summary from the Larimer County Department of Health and Environment and a City communication log are also attached (Attachments 3 and 4). Next Steps The City will reconvene the Technical Advisory Committee (TAC) to review the Program Response Guidelines and make recommendations regarding changes. City staff is reviewing West Nile Virus Management Plans from other jurisdictions, including Boulder (Attachment 5). Staff also requested information from Fort Worth, TX and learned that they do not have a written West Nile virus or mosquito management plan Additionally, the City will more actively engage the community to seek their input on October 29, 2013 Page 3 the West Nile virus Response Guidelines, particularly related to the community’s tolerance for adulticiding. ATTACHMENTS 1. 2008 West Nile Virus Response Policy 2. 2013 West Nile Virus Response Plan 3. 2013 West Nile Cases, Fort Collins Only, with zones 4. Communication Log 5. Boulder WNV Management Plan 6. Powerpoint presentation ATTACHMENT 1 Page 1 of 6 Program Response Guidelines to Mosquito-Borne Arboviral Activity March 2013 Off Season Activities Status: • No human cases occurring • Mosquito activity none to very low • Mosquito infection rates 0 • Vector index 0 Operational Response: 1. Routine post-season analysis of previous season’s data; assess response and efficacy. 2. Analyze and map data from prior years to develop surveillance strategy and select mosquito-trapping sites. 3. No mosquito testing. Communication Activities: 1. Updating of public outreach plan with any new information (e.g. at-risk populations). 2. Update FAQ’s and other information that may be needed if spraying occurs. ATTACHMENT 2 Page 2 of 6 Level I Early Season - June Status: • No human cases reported • Evidence of average or lower than average Culex species mosquito populations (as compared to available historical population data for the area) • Mosquito infection rates < 2 per thousand (0.2%) • Vector index < 0.5 Probability of Human Outbreak: Low Operational Response: 1. Initiate surveillance program. 2. Initiate larval control activities June 1st. 3. Brief City Manager on surveillance activities, mosquito-borne virus epidemiology and trigger points for recommendation of emergency control measures. Communication Activities: 1. Establish communication channels between appropriate City and County staff. 2. Ensure online information is up to date and prepare for ongoing, timely updates. 3. Initiate public education program on mosquito source reduction and risk reduction practices Communication Topics: o West Nile Virus basics o Wear repellent o Eliminate breeding sites Page 3 of 6 Level II Peak Season – July thru August – Low West Nile Virus Activity Status: • Sporadic human cases are being reported • No infected human blood donors have been reported • Culex mosquito populations increasing, but below historical average for that time period • Mosquito infection rate < 2 per thousand (0.2%) • Vector index < 0.5 Probability of Human Outbreak: Low – Moderate Operational Response: 1. Analyze and map surveillance data to identify areas of increased risk. 2. Continue mosquito pool submissions from surveillance program for West Nile virus testing with Colorado State University. 3. Brief City Manager on surveillance findings and need for quick action if activity rapidly increases. 4. Increase larval monitoring and control where necessary. 5. Begin planning for adulticide control in the event that virus activity and Culex populations rapidly rise. Communication Activities: 1. Notify local agencies, media and the public of positive findings. 2. Increase public education activities 3. Continue to regularly update online information, including maps illustrating risk areas. 4. Optional: targeted outreach to high-risk areas including: a. Door hangers b. Online outreach via NextDoor c. Posters and signage d. Coordination with Poudre School District and Colorado State University Communication Topics Overall: o West Nile Virus Basics o Wear repellent o Eliminate breeding sites o WNV policy and spraying decision parameters o How to get notified of mosquito spraying Communication Topics To Targeted Areas: o West Nile Virus risks and symptoms o Wear repellent o WNV policy and spraying decision parameters o How to get notified of mosquito spraying Page 4 of 6 Level III Peak Season – July thru August – Increasing West Nile Virus Activity Status: • More than one human case being reported per week in Fort Collins – OR – • More than one positive human blood donor reported for the season. -AND- • Culex mosquito populations increasing and at or above historical average by 1 standard deviation for that time period– OR – • Mosquito infection rates of > 3.0 per thousand (0.3%) and increasing – OR – • Vector index > 0.75 and increasing Probability of Human Outbreak: High Operational Response: 1. Enhanced communications between City and County regarding positive findings and anticipated response activities. City Manager apprised of threat levels and activities on an ongoing basis. 2. Identify geographic areas, by mapping surveillance data, where virus transmission appears most active. 3. Continue larviciding activities. 4. In the event the Health Department recommends adulticide spraying and the City Manager decides to proceed, commence adulticide operations. Communication Activities: 1. Coordinate press releases and a wide range of other activities to keep the public informed of affected areas, focusing on exposure risk reduction practices and public education of the disease threat. 2. Intensify existing public education activities and initiate public education/information on the adulticide program 3. Notify residents of affected and adjacent areas and people on the subscription notification list. 4. Notify appropriate agricultural interests (i.e. bee keepers, organic growers, etc.) and individuals on the Pesticide Sensitivity Registry of intended adulticiding activities, times, affected areas, etc. Also notify residents in areas that will not be part of the adulticide applications. Communication Topics o West Nile Virus risks and symptoms o Wear repellent o WNV policy and spraying decision parameters o How to get notified of mosquito spraying Page 5 of 6 Level IV Peak Season – July thru August – Emergency Level Status: • Multiple neuroinvasive human cases being reported in Fort Collins - AND – • Culex mosquito populations increasing and at or above historical average by 1 standard deviation for that time period - AND – • Sustained mosquito infection rates of > 5.0 per thousand (0.5%) – OR – • Vector index > 0.75. Probability of Human Outbreak: In progress Operational Response: 1. Expand mosquito surveillance activities (i.e. population densities, vector index and infection rates) to direct mosquito control efforts where risk to exposure is greatest and to monitor pre- and post-adulticide treatment conditions. 2. In the event the Health Department recommends additional adulticide spraying and the City Manager decides to proceed, continue spraying. 3. Secure any needed emergency funding and document costs associated with outbreak control. Communication Activities: 1. Focus as many resources as possible on public education and information; intensify all activities and involve public officials as spokespersons. Consider emergency measures to restrict outdoor activities. 2. Continue public education and information on the adulticide program including pesticides to be used, toxicity, application times, area of application, exposure reduction suggestions, justification, FAQ’s, etc. Notify residents of affected and adjacent areas and people on the subscription notification list. 3. Notify appropriate agricultural interests (i.e. bee keepers, organic growers, etc.) and individuals on the Pesticide Sensitivity Registry of any continued adulticiding activities, times, affected areas, etc. Also notify residents in areas that will not be part of the adulticide applications Communication Topics: o West Nile Virus risks and symptoms o Wear repellent o WNV policy and spraying decision parameters o How to get notified of mosquito spraying Page 6 of 6 Spraying Communication Activities 1. Coordinate communication with Colorado State University and Poudre School District for assistance in communicating spraying activities. 2. Focus all available resources on spraying notification. Communication Topics: o Spraying details: where and when o High quality map (interactive?) o Chemical used o Precautions to take: people, pets, gardens o Opt-out ability o Future spray notifications o WNV policy and spraying decision parameters o Special event contact (i.e., if you are planning a special event outside, please contact PERSON to coordinate spraying activities) PENDING IDEAS UNDER FURTHER INVESTIGATION • GPS tracking and real-time mapping of spray trucks • Mobile app to notify of spraying activities • Interactive online map of searchable addresses and spray zones • Opt-in phone notification system • Advisory Panel Orientation and Communication 2013 West Nile Cases Fort Collins Only, With Zones Case Number Report Date Onset Date Days onset to report City ZIP FC city FC zone Clinical Syndrome Onset week Onset wk ‐ 1 Onset week ‐2 340348 9/10/2013 6/30/2013 72 FORT COLLINS 80525 city 7 Uncomplicated Fever 27 26 25 338002 7/30/2013 7/3/2013 27 FORT COLLINS 80526 city 5 Uncomplicated Fever 27 26 25 338876 8/14/2013 7/7/2013 38 FORT COLLINS 80526 city 6 Uncomplicated Fever 28 27 26 339242 8/21/2013 7/15/2013 37 FORT COLLINS 80525 city 3 Uncomplicated Fever 29 28 27 337778 7/25/2013 7/18/2013 7 FORT COLLINS 80528 city 7 Meningoencephalitis 29 28 27 338685 8/12/2013 7/22/2013 21 FORT COLLINS 80525 city 5 Uncomplicated Fever 30 29 28 338546 8/8/2013 7/22/2013 17 FORT COLLINS 80526 city 6 Uncomplicated Fever 30 29 28 340432 9/11/2013 7/22/2013 51 FORT COLLINS 80528 city 7 Uncomplicated Fever 30 29 28 338789 8/13/2013 7/24/2013 20 FORT COLLINS 80525 city 7 Uncomplicated Fever 30 29 28 338675 8/12/2013 7/25/2013 18 FORT COLLINS 80526 city 6 Uncomplicated Fever 30 29 28 338396 8/6/2013 7/27/2013 10 FORT COLLINS 80525 city 6 Meningitis 30 29 28 339551 8/27/2013 7/30/2013 28 FORT COLLINS 80525 city 3 Uncomplicated Fever 31 30 29 338613 8/9/2013 8/1/2013 8 FORT COLLINS 80524 larval L1 Meningoencephalitis 31 30 29 340346 9/10/2013 8/1/2013 40 FORT COLLINS 80525 city 7 Uncomplicated Fever 31 30 29 339626 8/28/2013 8/1/2013 27 FORT COLLINS 80528 city 7 Uncomplicated Fever 31 30 29 339478 8/26/2013 8/3/2013 23 FORT COLLINS 80525 city 5 Uncomplicated Fever 31 30 29 338873 8/14/2013 8/4/2013 10 FORT COLLINS 80526 city 6 Uncomplicated Fever 32 31 30 338874 8/14/2013 8/5/2013 9 FORT COLLINS 80521 city 2 Uncomplicated Fever 32 31 30 339396 8/23/2013 8/5/2013 18 FORT COLLINS 80524 city 1 Uncomplicated Fever 32 31 30 338872 8/14/2013 8/5/2013 9 FORT COLLINS 80526 city 4 Meningitis 32 31 30 339399 8/23/2013 8/6/2013 17 FORT COLLINS 80525 city 7 Uncomplicated Fever 32 31 30 339082 8/19/2013 8/7/2013 12 FORT COLLINS 80525 city 7 Uncomplicated Fever 32 31 30 339080 8/19/2013 8/7/2013 12 FORT COLLINS 80528 city 7 Uncomplicated Fever 32 31 30 339634 8/28/2013 8/8/2013 20 FORT COLLINS 80524 city 3 Uncomplicated Fever 32 31 30 339283 8/21/2013 8/8/2013 13 FORT COLLINS 80525 city 3 Uncomplicated Fever 32 31 30 339165 8/20/2013 8/8/2013 12 FORT COLLINS 80526 city 4 Uncomplicated Fever 32 31 30 339166 8/20/2013 8/8/2013 12 FORT COLLINS 80526 beyond larval ‐ Uncomplicated Fever 32 31 30 339919 9/3/2013 8/8/2013 26 FORT COLLINS 80528 city 7 Uncomplicated Fever 32 31 30 341681 10/2/2013 8/9/2013 54 FORT COLLINS 80525 city 7 Uncomplicated Fever 32 31 30 341101 9/23/2013 8/9/2013 45 FORT COLLINS 80526 city 4 Uncomplicated Fever 32 31 30 339081 8/19/2013 8/10/2013 9 FORT COLLINS 80521 city 2 Uncomplicated Fever 32 31 30 339398 8/23/2013 8/11/2013 12 FORT COLLINS 80521 larval L2 Uncomplicated Fever 33 32 31 339247 8/21/2013 8/11/2013 10 FORT COLLINS 80524 beyond larval ‐ Uncomplicated Fever 33 32 31 339631 8/28/2013 8/11/2013 17 FORT COLLINS 80524 city 1 Meningitis 33 32 31 339469 8/26/2013 8/11/2013 15 FORT COLLINS 80528 city 7 Uncomplicated Fever 33 32 31 339823 8/30/2013 8/11/2013 19 FORT COLLINS 80528 larval L7 Uncomplicated Fever 33 32 31 339248 8/21/2013 8/12/2013 9 FORT COLLINS 80525 city 3 Uncomplicated Fever 33 32 31 339394 8/23/2013 8/13/2013 10 FORT COLLINS 80521 city 2 Encephalitis 33 32 31 339724 8/29/2013 8/16/2013 13 FORT COLLINS 80524 city 3 Uncomplicated Fever 33 32 31 340430 9/11/2013 8/16/2013 26 FORT COLLINS 80526 city 4 Uncomplicated Fever 33 32 31 339397 8/23/2013 8/17/2013 6 FORT COLLINS 80525 city 5 Uncomplicated Fever 33 32 31 341537 9/30/2013 8/17/2013 44 FORT COLLINS 80525 city 5 Uncomplicated Fever 33 32 31 339470 8/26/2013 8/17/2013 9 FORT COLLINS 80528 city 7 Uncomplicated Fever 33 32 31 340294 9/9/2013 8/18/2013 22 FORT COLLINS 80525 city 5 Meningitis 34 33 32 2013 West Nile Cases Fort Collins Only, With Zones Case Number Report Date Onset Date Days onset to report City ZIP FC city FC zone Clinical Syndrome Onset week Onset wk ‐ 1 Onset week ‐2 339918 9/3/2013 8/19/2013 15 FORT COLLINS 80526 city 4 Uncomplicated Fever 34 33 32 339825 8/30/2013 8/20/2013 10 FORT COLLINS 80521 city 2 Uncomplicated Fever 34 33 32 340791 9/18/2013 8/20/2013 29 FORT COLLINS 80524 city 1 Uncomplicated Fever 34 33 32 340090 9/5/2013 8/22/2013 14 FORT COLLINS 80524 city 1 Uncomplicated Fever 34 33 32 339824 8/30/2013 8/24/2013 6 FORT COLLINS 80524 city 1 Uncomplicated Fever 34 33 32 340565 9/13/2013 8/28/2013 16 FORT COLLINS 80524 beyond larval ‐ Uncomplicated Fever 35 34 33 340349 9/10/2013 8/28/2013 13 FORT COLLINS 80525 city 3 Uncomplicated Fever 35 34 33 340347 9/10/2013 9/1/2013 9 FORT COLLINS 80524 city 1 Uncomplicated Fever 36 35 34 340671 9/16/2013 9/4/2013 12 FORT COLLINS 80524 city 3 Meningitis 36 35 34 340625 9/16/2013 9/6/2013 10 FORT COLLINS 80521 city 2 Uncomplicated Fever 36 35 34 341348 9/26/2013 9/7/2013 19 FORT COLLINS 80525 city 5 Uncomplicated Fever 36 35 34 340670 9/16/2013 9/7/2013 9 FORT COLLINS 80525 city 7 Uncomplicated Fever 36 35 34 341245 9/25/2013 9/10/2013 18 FORT COLLINS 80521 city 2 Uncomplicated Fever 37 36 35 341247 9/25/2013 9/10/2013 15 FORT COLLINS 80521 city 2 Uncomplicated Fever 37 36 35 341102 9/23/2013 9/12/2013 11 FORT COLLINS 80521 larval L2 Meningitis 37 36 35 341595 10/1/2013 9/13/2013 18 FORT COLLINS 80526 city 4 Uncomplicated Fever 37 36 35 339105 8/19/2013 8/15/2013* FORT COLLINS 80525 city 5 Blood donor 339108 8/19/2013 8/16/2013* FORT COLLINS 80526 city 4 Blood donor 339391 8/23/2013 8/21/2013* FORT COLLINS 80526 city 2 Blood donor WNV Patients *for blood donors, "onset" is date blood was donated Population Ave age 46.4 Cases by Zip in Zip Code Rate per 100,000 Med. Age 50 Fort Collins Days from onset to report to 80521 9 28,674 31.38732 average 19.3 80524 12 33,400 35.92814 Male 27 80525 18 49,678 38.24631 Female 33 80526 13 45,214 33.17557 80528 8 20,462 39.09686 All FC zip codes 60 177,428 33.81653 FC Addresses Neuroinvasive rate LAB‐confirmed Infections, Fort Collins addresses 5.072480105 9 neuroinvasive cases (3 encephalitis, 6 meningitis) 3 blood donors 51 West Nile fever cases Communications and Public Involvement Office 215 N. Mason St. PO Box 580 Fort Collins, CO 80522 970.221.6882 970.221.6586 - fax fcgov.com WEST NILE VIRUS COMMUNICATIONS LOG – 2013 Season The following list details all external communications efforts regarding West Nile virus. Initial communications efforts focused largely on education, prevention and encouraging residents to sign up for spraying notification. As the timeline moved closer to the potential for spraying, the messaging began to emphasizing sign up for spraying (first and foremost), followed by education and prevention. Finally, once spraying was announced, all messaging focused on spraying timing and details.  June 1: Cable 14 beings playing 30‐second “Fight the Bite” PSA  June 20: Fcgov.com/westnile updated for 2013 o Education, prevention, backyard inspection program  June 25: 47,000 Utility Bill inserts mailed (July utility bills, mailed 6/25‐7/25) o English & Spanish o Education, prevention, backyard inspection program  June 25: Cable 14 bulletin board posted o Plays continuously  July 16: Twitter post, 1 retweet o Sign up for email alerts about spraying  July 16: Fort Shorts article o Prevention focus ATTACHMENT 4  July 18: Cable 14 bulletin board updated o Plays continuously  July 18: fcgov.com/westnile page updates  July 22: Citynet Spotlight, has been updated as information has changed  July 23: fcgov.com/westnile page updates o Prevention information o Management policy  July 23: news release, front page Coloradoan o Counts increasing; prevention tips  July 23: Twitter post, 0 retweets o Counts increasing  July 25: fcgov.com/westnile content updated o Prevention tips  July 26: news release, front page Coloradoan o Counts increasing; door‐hanger distribution  July 26: Facebook post, 723 reach, 1 share o Sign up for email alerts about spraying  July 26: Twitter post, 0 retweets o Counts increasing  July 26: Nextdoor.com post, 4 thank yous o To 8 high‐risk neighborhoods o Counts increasing; sign up for email alerts about spraying  July 27 & Aug. 3: 22,000 door hangers distributed o English & Spanish o High‐risk neighborhoods  August 2: Email sent to all City support staff o Addresses how to answer WNV questions  Aug. 1‐10: fcgov.com home page spotlight o Counts increasing o Sign up for email notification of spraying  Aug. 2: Facebook post reached 1,140; 2 likes o Report mosquito breeding areas  Aug. 3: fcgov.com/westnile content updated o Backyard inspections  Aug. 3: Facebook post reached 441 o Backyard inspections On August 10, the City Manager approved the recommendation to spray and the following communications commenced:  Aug. 12: Everbridge call o North of Mulberry o English & Spanish o Spraying notification  Aug. 12: fcgov.com/westnile content updated o Spraying notification & map  Aug. 12: news release, front page story on Coloradoan o Spraying notification & map  Aug. 12: Email notification out to 3640 subscribers o Spraying notification & map  Aug. 12: Facebook post reached 23,712 followers; 309 shares; 135 comments; 24 likes o Spraying notification and map  Aug. 12: Nextdoor.com post received 19 thank you’s; 18 comments o One to 16 neighborhoods north of Mulberry o One to 73 neighborhoods south of Mulberry o Spraying notification and map o Follow up on Aug. 14 re: GPS maps  Aug. 12: Twitter post, 5 retweets o Spraying notification  Aug. 12‐21: fcgov.com home page spotlight o Spraying notification o Updated Aug. 14 to also include GPS information  Aug. 13: Everbridge call o South of Mulberry o English & Spanish o Spraying notification  Aug. 14: Everbridge call o North of Mulberry o English & Spanish o Spraying reminder  Aug. 14: fcgov.com/westnile content updated o Links and instructions to GPS maps  Aug. 14: news release; front page story on Coloradoan o GPS truck tracking  Aug. 14: Email notification out to 3640 subscribers o GPS truck tracking  Aug. 14: 4 Facebook posts – total: 11,455 reach; 35 shares; 56 comments; 47 likes o GPS truck tracking o Ongoing through web/tech issues that evening  Aug. 14: 4 Twitter posts, 14 total retweets o GPS truck tracking o Ongoing through web/tech issues that evening  August 14: Cable 14 posts bulletin board posting spraying dates and zones  Aug. 15: Everbridge call o South of Mulberry o English & Spanish o Spraying reminder  Aug. 16: email reminders to 3640 subscribers  Aug. 18: Everbridge call o North of Mulberry o English & Spanish o Spraying reminder  Aug. 19: Everbridge call o South of Mulberry o English & Spanish o Spraying reminder  Aug. 19: email reminders to 3640 subscribers o Plus Recreator database  Aug. 19: Facebook posts o Spraying reminder o Posted updated truck progress maps  Aug. 19: Twitter post o Spraying reminder  Aug. 19: Nextdoor post o Spraying reminder  Aug. 20: email reminders to 3640 subscribers o Plus CSU subscribers  Aug. 20: Twitter Post o Spraying reminder o Posted updated truck progress maps February 2006 Prepared by: City of Boulder Ofﬁce of Environmental Affairs In collaboration with OtterTail Environmental Inc. CITY OF BOULDER WEST NILE VIRUS MOSQUITO MANAGEMENT PLAN goals objectives protection prevention ATTACHMENT 5 2 wnv mosquito management table plan of contents TABLE OF CONTENTS EXECUTIVE SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 BACKGROUND. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 HISTORY OF CITY OF BOULDER WEST NILE VIRUS PROGRAM . . . . . . . . . . . . . . . . . . . . . 5 GOALS AND OBJECTIVES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 CHAPTER 1: NUISANCE MOSQUITOES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 CHAPTER 2: LARVAL MOSQUITO MANAGEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Preferred Larval Control Agents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Application of Bti . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Potential Impacts of Bti to Nontarget Species . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Monitoring Study of Local Bti Impacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Potential Effects of Bti to Human Health . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Potential Impacts to Water Quality from Bti . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Potential Effects to Water Quality from the Manufacturing Process to Bti . . . . . . . . . . . . . 11 Managing Flood-irrigated Lands on Open Space and Mountain Parks Lands . . . . . . . . . . . 11 Other Larval Mosquito Control Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Application of Bacillus sphaeicus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Mosquito Habitat Manipulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Techniques Considered But Not Recommended for Larval Mosquito Control. . 12 Application of Methoprene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Introduction of Predatory Fish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Application of Oils or Monomolecular Surface Films . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Larval Mosquito Monitoring Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Thresholds for Increased Larval Vigilance and Management . . . . . . . . . . . . . . . . . . . . . . . 15 Larval Monitoring Protocol. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Larval Control Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Larvicide Application Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Bti Handling and Spill Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 CHAPTER 3: ADULT MOSQUITO MANAGEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Adult Mosquito Monitoring Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Adult Mosquito Monitoring Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Trap Site Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Trap Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Pooled traps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 WNV Detection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Adult Mosquito Control - Contingency Management . . . . . . . . . . . . . . . . . . . . . . . 22 Preferred Adult Control Agents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Potential Impacts of Adult Control Agents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Thresholds for Initiating Adult Mosquito Control . . . . . . . . . . . . . . . . . . . . .24 Explanation of Mosquito Infection Rates and the Vector Index . . . . . . . . . . . . . . . . . . . . . 25 Adult Mosquito Control Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 WNV No-spray List. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Precautions and Notiﬁcation Prior to Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Example of Adult Mosquito Spraying Schedule . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 CHAPTER 4: COMMUNICATION PLAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 LIST OF TABLES & FIGURES Table 2-1 Literature Review of Toxic Effects from Bti on Non-target Organisms . . . . . . . . . . . . 9 Table 2-2 Annual Baseline Larval Mosquito Monitoring and Control Plan . . . . . . . . . . . . . . . . 15 Table 2-3 Increased Monitoring and/or Management Plan for Larval Sites . . . . . . . . . . . . . . . 16 Table 3-1 Adult Mosquito Monitoring Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Figure 2-1 Larval Breeding Site Locations and Categorization . . . . . . . . . . . . . . . . . . . . . . . . . 14 Figure 2-2 Larval Monitoring Flowchart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Figure 2-3 Larval Control Flowchart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Figure 3-1 Adult Mosquito Trap Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Figure 3-2 Adult Mosquito Monitoring Flowchart. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Figure 3-3 Vector Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Figure 3-4 Adult Mosquito Control Flowchart. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 3 Executive Summary In an effort to implement a long-term mosquito management strategy to reduce the threat of West Nile Virus (a mosquito-borne virus) to city residents, the city of Boulder has developed this West Nile Virus Mos- quito Management Plan. This plan is in compliance with and was guided by the city of Boulder 2002 Inte- grated Pest Management Policy. In Colorado, two species of mosquitoes are the primary contributors of West Nile Virus (WNV) to humans: Culex pipiens and Culex tarsalis. Beginning in May of each year, a base- line monitoring plan will be implemented and lands owned or managed by the city will be surveyed to evaluate whether either of these two species occurs. Areas that will be routinely surveyed include all known potential mosquito habitat areas found on city-owned lands within the city limits (approximately 524 acres) and on city-owned lands outside of the city limits (approximately 2431acres). The level of risk from mosquito-borne disease depends on the number of mosquitoes that are capable of transmitting the virus, the prevalence of the virus among them, and the density of the human population in an area where WNV is found. Proper monitoring of larval mosquitoes is an important component in identifying areas that are at high risk for transmission of WNV to humans. Monitoring of larvae can pro- vide information on the expected abundance of adult mosquitoes and can indicate areas where control efforts should be directed. Control efforts during the larval stage are the most cost-effective and efﬁcient means to eliminate mosquitoes at their source and, therefore, to most effectively reduce the risk of human infection. Measures to control mosquito larvae will consist of treatment of breeding habitats with a bac- terium (Bacillus thuringiensis subspecies israelensis, or Bti) that attacks the larvae. Control of the larvae limits the possible future need for non-biological control of adult target mosquitoes, such as pesticide fog- ging or spraying. Larval Monitoring and Control Plan Monitoring and treatment of larval sites will be similar to previous years, though the mapped sites have been categorized differently for this plan than in years past. Potential mosquito breeding sites have been categorized based on the combined results of the previous years of larval monitoring. During the years of surveillance, a portion of the potential breeding sites have never been found to be breeding mosquitoes, some sites were found to breeding only nuisance-type (non-Culex) mosquitoes, and other sites were found to be breeding Culex mosquitoes and received one or more control treatments. Therefore, it makes sense to differentiate between habitats and focus initial efforts at sites where Culex almost certainly will occur and/or where Culex mosquitoes are more likely to occur at some point during the season. Based on data collected from 2003-2005, the sites have been categorized as follows: Category I - Vector larval breeding sites: All sites where Culex larvae have been found breeding Category II - All mosquito larval breeding sites: All sites where only nuisance mosquito larvae have been found breeding (to date) Category III - All potential larval breeding sites: All potential mosquito breeding sites that have not been found breeding any type of mosquitoes (to date) In general, Boulder’s mosquito season occurs May through September, while the peak season for Culex breeding is June through August. Larval monitoring and control will occur at all Category I sites once per week, May-September. Category II sites will be monitored once per week during the height of the Culex breeding period, June-August. Monitoring at Category III sites (all remaining mapped potential larval breeding sites) will occur once during the peak season as a measure of quality control. Since climate can be a large contributor to seasonal Culex habitat trends, seasonal temperature and precipitation patterns will also help determine the frequency at which sites will be monitored. The plan also allows for maximum ﬂexibility in monitoring and control, should a combination of thresholds be met at any point in the season that may warrant increased vigilance and/or management. Thresholds for increased larval monitoring between site categories include: • A signiﬁcant percentage (~50%) of Category I sites that are breeding Culex larvae in May, • Early detections of WNV in area adult sentinel traps, • High or rapidly increasing adult Culex mosquito populations in general, and • Early or rapidly increasing cases of WNV in humans and/or birds. wnv mosquito management plan executive summary 4 Adult Monitoring and Contingency Control Plan Proper monitoring of adult mosquitoes, which includes testing for the presence of WNV, is important in guiding prevention and control because it can provide information on the potential threat to residents and can indicate areas where efforts to eliminate mosquitoes should be targeted. Adult mosquito monitoring will continue as in years before in the established trap locations. All 16 city traps are monitored weekly for WNV in adult mosquito populations during the peak of Culex activity (June-August). The city’s adult mon- itoring does not cover the entire length of mosquito season (or potential Culex breeding period), though forewarning of especially early or late season Culex activity in adult traps can be gathered from contacting partner agencies on a regular basis. Monitoring adult traps for WNV presence will occur earlier (May) or later (September) or more frequently than planned if data from local partner agencies (Colorado Dept. of Health, Boulder County Public Health, Colorado University) indicate that there are early, rapidly increasing, or high sustained levels of Culex mos- quito populations and/or early, elevated, or sustained cases of WNV present in birds and/or humans. A continued and extensive communication network will serve as the best resource to make the most in- formed decisions on monitoring and control of WNV. This network involves city agencies, regulatory agen- cies, and other bodies associated with monitoring of WNV. The presence of mosquito-borne pathogens in Boulder, if detected, will prompt one or more responses or interventions. Monitoring data will be used to assess the risk of an outbreak of human disease and the need to apply pesticides in a limited and targeted area to control adult mosquitoes. The control response will depend on a combination of thresholds being met that include, but are not limited to: • the overall intensity and persistence of the WNV activity in adult Culex mosquitoes, humans, birds, and non-avian vertebrates • the proximity of WNV activity to human populations within the city, • the time of year, • vector index level, and • seasonal climate. Final recommendations on adult control activities will weigh heavily on recommendations from the City of Boulder management staff, partner agencies, Center for Disease Control (CDC), and Environmental Protec- tion Agency (EPA). The thresholds established for implementation of adult mosquito control activities is based on ﬁnding WNV in C. tarsalis or C. pipiens adult females. Meeting or exceeding these thresholds does not directly correlate to spraying pesticides every time WNV is discovered in adult mosquitoes. Control for adult mosquitoes will be determined on a site-speciﬁc basis. Background West Nile Virus is a disease that was ﬁrst detected in the United States during the summer of 1999 in New York City and has since spread westward across the U.S. During the 2003 mosquito season, Colorado led the nation in WNV human cases (2,945) and WNV-related deaths (55) (CDPHE 2004). WNV activity and hu- man cases have since decreased in Colorado, but continues to be an annual threat. WNV is maintained in the bird population. Mosquitoes are usually not carriers of WNV until they bite an infected bird. An in- fected mosquito may then pass the virus on to humans, horses and other animals through an additional bite. Although many people who contract WNV experience no or very mild symptoms, WNV infection can result in severe and sometimes fatal illnesses. There are approximately 54 species of mosquitoes in Colorado, yet only the species from the genus Culex are known to be effective transmitters of the virus, also known as vectors. The city of Boulder’s control plan focuses only on controlling vector populations since other mosquito species are not directly involved in the disease transmission process. Through surveillance of potential mosquito breeding sites, areas iden- tiﬁed as containing vector species are identiﬁed and treated with biological control agents. This method of targeting prevents the mosquitoes from developing into adults and transmitting the virus, and is the most cost effective and accurate way to reduce vector populations. In addition, control of the larvae limits the possible future need for non-biological control of adult mosquitoes such as ultra-low volume (ULV) pesticide spraying. wnv mosquito management plan 4 executive summary 5 Prior to the WNV outbreak in Colorado in 2003, the city of Boulder did not historically control mosquitoes. The city’s policy was that the nuisance created by mosquitoes was not signiﬁcant enough to warrant pesticide application. Although the city had not been controlling mosquitoes on its lands, Boulder County had been controlling mosquitoes on unincorporated county lands and various other lands not owned by the City. These control efforts are administered by the Boulder County Public Health department (BCPH) and are designated as the Boulder County Mosquito Control District. The Boulder County Mos- quito Control District was delineated by the county commissioners and is funded by a tax on the residents of the district. The county’s control program has historically focused on controlling nuisance mosquitoes and activities including control of both larval and adult mosquitoes. The program for controlling mosquitoes described in this plan differs from the county’s past efforts in two primary ways. First, the city is currently responsible for funding its own mosquito control efforts. Second, to maximize the protection of the environment, the city is not attempting to control nuisance mosquitoes, but instead, is focusing its efforts on protecting human health by controlling only the mosquito species that can effectively transmit WNV. Therefore, any mosquito breeding habitats that do not contain the species targeted in this plan will not be treated, even if signiﬁcant numbers of nuisance mosquito species are found. Despite the differences between the goals of the city’s program and the county’s program, both parties are working closely together to assure that a collab- orative effort is undertaken to minimize the risk to human health from WNV. History of City of Boulder WNV Program WNV ﬁrst appeared in Colorado in humans in 2002. Trends in the spread of the virus pre- dicted that the spread of WNV would continue westward and that cases in Colorado would likely be much higher the following year. As predicted, Colorado led the country in WNV cases in 2003. In a proactive measure, the city of Boulder contracted with OtterTail Environmental, Inc. in early 2003 to develop and implement a mosquito control program that both reduced the risk of WNV to human health and minimized adverse effects to environmental health and function. The program focus is on prevention and early detec- tion and control of vector larvae in the Culex genus. As part of the early detection work, OtterTail surveyed and mapped all potential mosquito breeding habitat on city-owned properties within or near city limits in 2003 and 2004. This map (see Figure 2-1), which serves as a basis for all monitoring efforts, identiﬁes 488 individual potential breeding sites that cover 2,955 acres. Since 2003, the program has become more reﬁned. As a result of three years of monitor- ing data, the program is now able to implement a more cost-effective monitoring and control approach that continues to protect human and environmental health. The devel- opment of control thresholds and categorized sites based on vector presence has allowed the city to identify an annual baseline monitoring system (presented in this plan) for mos- quito control and WNV prevention that is more efﬁcient, reliable, and cost-effective. Goals and Objectives The overall goal of this WNV control effort is to reduce the risk of human WNV infection while providing the most limited effect to the environment possible. This goal will be achieved through a long-term mosquito monitoring and control program that is responsive to the public, environmentally sound, and cost-efﬁcient. This plan is directed primarily at controlling the larval stages of mosquitoes and their sources. Control will generally be con- tained in localized areas to lessen the environmental impacts. Control of adult mosquitoes may be employed, but only in emergencies, after certain criteria are met which warrant adult treatment. The comprehensive nature of this plan ensures the efﬁcacy of the control measures while minimizing adverse impacts to human health and the environment. wnv mosquito management goals plan & objectives 5 6 The objectives that have been used to accomplish this goal are: Objective 1: Categorize the habitats that support mosquitoes that most effectively trans- mit WNV to humans. This categorization allows the city to focus its initial monitoring and treatment efforts in habitats that have bred Culex species or could potentially breed Culex larvae, and, therefore, will reduce the number of treated sites compared to standard control practices (many other control programs across the country treat all habitats where signiﬁcant mosquito populations are found, regardless of the species). Targeting efforts in this way will substantially reduce the environmental impacts to the city’s wet- lands and other water resources as well as labor costs of automatically sur- veying every wet area, regardless of Culex suitability. Objective 2: Apply the larvicide (Bti) to all sites where Culex species are found. This effort reduces the potential for adult vector mosquitoes to hatch. It also lowers the potential need for spraying with pesticides that are more hazardous if WNV becomes an epidemic. Objective 3: Use adult mosquito monitoring to provide an early warning system of the occurrence of WNV within and near city limits. Data collection will include: (a) conducting direct WNV testing in the adult mosquito populations of the two species of mosquito that most effectively transmit WNV to humans; and, (b) coordinating with local and state agencies on the results of this testing. Data will also be collected on the locations of actual WNV outbreaks (for mosquitoes, birds, and mammals) on lands owned by the city. Objective 4: Develop trigger mechanisms to respond to early larval detection and/or heightened mosquito activity to appropriately increase management activity. Objective 5: Utilize thresholds for initiating adult mosquito control in emergency cases. Objective 6: Continue the program to educate the public about WNV and increase aware- ness of the city’s WNV Mosquito Management Plan. This program will inform the public about the need for efforts to control vector mosquitoes and will describe what these efforts will entail. wnv mosquito management goals and plan objectives nuisance mosquitos 7 CHAPTER 1: NUISANCE MOSQUITOES Mosquitoes pose both a nuisance problem and a West Nile Virus threat to a community. There are over 50 species of mosquitoes in Colorado -two of them are known to effectively transmit West Nile Virus to humans. Nuisance mosquitoes are those mosquitoes that do not carry disease. For example, “ﬂood water” mosquito populations can increase after signiﬁcant rainfall amounts and are aggressive biters, but they are not known to transmit WNV to humans. Nuisance mosquito population trends have stayed fairly constant in the Boulder area over the past several years. However, because of West Nile Virus, the public seems to be more in-tune and concerned about nuisance mosquitoes than in the past. In this plan, the city of Boulder has a comprehensive and proactive approach to managing mosquitoes that may carry WNV. The plan focuses on larval control of the two species that can most effectively transmit WNV, Culex tarsalis and Culex pipiens. All habitat sites with Culex occurrences are treated with Bti (Bacillus thuringiensis israelensis), since larval control is the most effective way to reduce mosquito populations. This plan also includes emergency spraying/fogging of adult mosquitoes if thresholds for spraying are met. Sixteen adult mosquito traps are placed throughout the city and are monitored weekly from June through August to determine the number of Culex mosquitoes present in the area. Community outreach and education is essential in helping individuals understand WNV and take simple precautions that can be taken to help prevent a disease outbreak. The city’s strategy is a balanced ap- proach of individual responsibility and city action to control, as reasonably as possible, the threat of WNV. The city’s Integrated Pest Management (IPM) policy (Appendix A) provides direction for managing pest and nuisance problems including weeds, insects, and animals on public lands. This policy directs that the least toxic controls be used and that “alternative” methods be taken before spraying pesticides is considered. Spraying pesticides is only done as a last resort. Non-chemical methods and means to be considered to control nuisance mosquitoes follow the IPM protocol of (1) prevention/ education (2) cultural controls (3) mechanical controls and (4) biological controls. The following are some examples of these types of controls: Prevention/Education: • Information for the prevention of larval development and adult mosquito bites • Limited public distribution of repellant at some community facilities Cultural Control • Removing mosquito harborage areas where possible Mechanical Controls • Mosquito magnets • Street sweeping to help move standing water in curb lines • Storm drain cleaning of debris so water moves Biological Controls • Bat and bird houses - encourage natural mosquito predators chapter one larval mosquito management 8 CHAPTER 2: LARVAL MOSQUITO MANAGEMENT Efforts to control mosquitoes conducted during the larval stage of mosquito development are the most ef- fective and environmentally sound way to eliminate target mosquitoes and, therefore, to most effectively reduce the risk of human WNV infection. The U.S. Environmental Protection Agency’s (EPA) Ofﬁce of Pesti- cide Programs is responsible for ensuring that a pesticide will not pose unreasonable adverse effects to human health and the environment. To prevent and minimize the impacts of pesticides on ﬁsh, wildlife and plants, the U.S. Fish and Wildlife Service provides technical assistance and consults with the EPA during registration and re-registration of pesticides. In Colorado, pesticide rules and regulations are administered and enforced by the Colorado Department of Agriculture, Division of Plant Industry. Preferred Larval Control Agents Larval control agents (larvicides) are materials that target the larval stage of the insect and prevent mosqui- toes from becoming adults. The preferred larval control agent proposed for use under this plan is the micro- bial insecticide Bacillus thuringiensis subspecies israelensis, or Bti. This product is discussed below. Application of Bti Bti is a microbial insecticide formulated for use to control mosquito larvae in aquatic habitats. The product is manufactured as corncob granules and is applied by hand or by using hand-held seeders (spreaders) and power spreaders. Bti is an augmentative biological control agent formed from bacterium that occurs natu- rally in soils. The bacterium produces protein crystal protoxins during the formation of spores that disrupt bodily functions in some insects (Extension Toxicology Network [ETN] 1996). This active ingredient of Bti is called a crystalline delta-endotoxin. Live bacteria are not contained in Bti; the active ingredient is separated from the bacteria that are killed in a laboratory. When they are ingested by the mosquito larvae, the pro- toxins dissolve in the intestine and the delta-endotoxin reacts with the stomach secretions. The cells in the gut then become paralyzed, interfering with normal digestion and triggering the insect to stop feeding (ETN 2003). Death typically occurs within a few hours of ingestion. Bti adversely affects larval stages of species in the Order Diptera, Suborder Nematocera, Family Culicidae (mosquitoes). Research and ﬁeld experiments have shown that Bti has no toxic effects on beneﬁcial and predacious arthropods or insects such as honeybees, beetles, mayﬂies, dragonﬂies, damselﬂies, stoneﬂies, caddisﬂies and true bugs (CMC 2003). CMC (2003) also found that among Diptera (true ﬂies and midges) Chaoborus species, Ephydra riparia, Musca domestica, Odontomyia species, and Polypedilum species dem- onstrated no susceptibility to Bti. It was also determined that variable mortality did occur among Chrirono- mus pulmosus, Chrionomus stigmaterus, Dixa species, Goeldchironomus holoprasinus and Palpomyia spe- cies (CMC 2003). Low levels of toxicity were also observed among a few species of butterﬂies and moths, but CMC (2003) found no toxic effects occurring in crustaceans or amphibians. Using Bti to control larval mosquitoes offers several advantages. First, its residual lasts only 24 hours in water, and it breaks down rapidly as a result of exposure to ultraviolet light (EPA 1998, 2002; ETN 2003; National Pesticide Telecommunications Network [NPTN] 2000). Second, it does not affect nontarget verte- brate species, such as ﬁsh and birds (EPA 1998 2002; ETN 2003; NPTN 2000). Third, the bacterium kills the mosquito larvae and ﬁeld technicians can observe the results the same day the Bti is applied. A negative effect is that part of the food chain is temporarily removed by killing the larvae and other dipterans, poten- tially affecting predators by removing a source of food. However, because Bti does not last long in water, adult mosquitoes and other dipterans could lay eggs in the treated water 24 hours after a treatment, and larvae could develop to provide another source of food to predators. Treatments are usually made after the larvae have been available to predators for up to two days of the normal four to ﬁve day larval stage. The application of Bti has been determined in this plan as the preferred method for larval mosquito control because it serves the greatest public need. The threat that WNV will infect residents of Boulder outweighs the impacts of this bacterium on the areas where it would be used. Larval treatments must occur to help contain and minimize the threat of WNV infection in humans. Adverse impacts to areas being treated will be minimized by applying Bti at recommended concentrations, and all treatment areas will be posted with signs before Bti is applied. chapter two impacts of Bti chapter two 9 Non-target Organism Effects Comments1 Small laboratory mam- mals (rat, rabbit) No unacceptable acute toxic effects Based on standard acute testing via inhala- tion, dermal exposure, and eye irritation Human infants & children No toxicity Prediction included 10x margin of safe- ty and special exposure patterns. Humans No endocrine or im- mune system effects No evidence known to exist by the EPA. Birds (mallard, bobwhite quail) No toxicity Based on standard acute and subacute testing. Insects (green lace-wing larvae, parasitic wasps, pre- daceous water beetles) Little to no toxicity Green lace-wings—16 day LC50 > 1.5 x 108 colony-forming units (cfu)/g diet; 16 day no-observed-effects-level (NOEL) = 2.5 x 104 cfu/g diet. Wasps—30 day LC50 > 7.9 x 107 cfu/g diet. Water beetles—9 day LC50 > 1.8 x 108 cfu/g diet. Honey bee Minimal toxicity 5 day LC50 > 7.0 x 107 cfu/g diet. Fish (trout, bluegill) No toxicity Trout—aqueous LC50 > 8.7 x 109 cfu/l and oral LC50 > 1.7 x 1010 cfu/g food, slightly toxic; aqueous LC50 > 1.4 x 1010 cfu/l and oral LC50 > 5.3 x 109 cfu/g food. Bluegill— aqueous LC50 > 8.9 x 109 cfu/l water and oral LC50 > 1.3 x 1010 cfu/g food; aqueous LC50 > 1.6 x 1010 cfu/l and oral LC50 > 4.3 x 109 cfu/g food. Freshwater invertebrates (Daphnia) Moderately toxic 21 day LC50 = 5-50 ppm. Plants (terrestrial, semi- aquatic, aquatic) Minimal risk of toxicity No evidence known to exist by the EPA. Mammalian wildlife Minimal to nonexis- tent risk of toxicity Based on known mammalian studies and 30 years of use. Soil invertebrates (nema- todes, ground beetles) Toxic (all strains of Bti) Toxic to some nematode and ground beetle species; indi- rect adverse effects likely for predators of such species. Invertebrate predators (ﬂies, dobsonﬂies, dragon- ﬂies, stoneﬂies, caddisﬂies) No negative impacts Study (Merritt and Wipﬂi 1994) included ﬁeld and lab testing for three years.3 Non-target invertebrates (nearly 100 species) No ill effects Reported by Garcia et al. 1980.4 Non-target aquatic insects (cad- disﬂies, mayﬂies, stoneﬂies, damselﬂies, dragonﬂies, water beetles), aquatic invertebrates (Daphnia, rotifers, crustaceans) No demonstrated effects Aquatic vertebrates (trout, sunﬁsh, frogs, salamanders), terrestrial vertebrates (mallard, mammals) No negative effects Benthic macroinvertebrate commu- 10 impacts of Btichapter two The Material Safety Data Sheet (MSDS) for Bti is included in Appendix B. Proper handling of Bti and procedures for spill control are summarized later in this chapter. Application re- quirements proposed for use under this plan are discussed in later sections. Potential Impacts of Bti to Nontarget Species The bacterium Bti has been studied and used as a mosquito larvicide for about 20 years. Hundreds of peer-reviewed scientiﬁc journal articles and government agency documents have been published about the potential for ecological effects from Bti. A review of several summary publications from reputable federal agencies suggests that Bti is non-toxic to nearly all types of nontarget organisms (in other words, the target organisms for Bti are all mosquitoes and black ﬂies), including other insects, with two exceptions. Bti is toxic to microorganisms in soil (such as nematodes) and may be toxic to Daphnia (a genus of fresh- water invertebrate crustacean), according to the EPA and Agriculture and Agri-Food Cana- da. This information is summarized in Table 2-1. Most of the studies cited by the summary documents were conducted in the laboratory for a short duration and considered only the effects to the study organisms themselves. Two studies published in 1998 provide contrasting evidence of more wide-ranging effects to nontarget species. FCCMC (1998) concluded that, although Bti is highly effective in killing the targeted mosquito larvae (C. tarsalis and C. pipiens), it is also lethal to many other in- sect species in several taxonomic orders besides Diptera (ﬂies). Some larval mortality of in- sect species that are normally associated with mosquito larvae in aquatic habitats was ob- served in the Families Chironomidae (midges), Ceratopogonidae (biting midges), and Dixidae (dixid midges). However, the concentration of Bti required to cause this effect was 10 to 1,000 times higher than normal application rates for controlling mosquitoes. Hershey et al. (1998) evaluated Bti applied for 3 years at normal rates to 27 wetlands and determined adverse impacts to insect and non-insect orders were delayed until the second year of application. In the second and third years of application, signiﬁcant reductions in insect abundance and insect species richness were observed. Overall, insect community composition was radically altered, and the authors speculated that many species were ad- versely affected indirectly via changes to the ecosystem structure. The authors also esti- mated that wetland function had been disrupted and degraded, likely causing indirect ef- fects to wetland vertebrates that could not be measured in the 3-year time frame. Monitoring Study of Local Bti Impacts An assessment of the affect of Bti on nontarget aquatic benthic organisms was conducted by Ottertail Environmental at a predetermined site in Boulder in August of 2003, 2004, and 2005. Quantitative Ponar samples were taken of the mosquito breeding habitat bottom substrate before, and three days after, the application of Bti. A control site was also sam- pled in a similar habitat type without the application of Bti. The aquatic substrates in the study area were highly heterogeneous, making it impossible to obtain replicate samples that captured the same microhabitat. This, combined with the knowledge that lentic (pond) habitats are typically difﬁcult to obtain reproducible results, continued to make reliable trend analyses of this data set difﬁcult at best. When comparing the total abundance numbers throughout the study period, there is a noticeable decrease observed from 2003 to 2005. However, the control had a similar decrease, suggesting that Bti was not the reason for the decrease over time. Many studies at a research-level analysis have been conducted over the years to determine the effects of Bti to nontarget organisms. These studies would be a more reliable tool for interpretation of probable impacts to nontarget organisms within the city of Boulder’s project area. A compilation of the results of these studies are presented in the literature review (Table 4-1). For these reasons, the local assessment study of Bti on nontarget aquat- ic benthic organisms was discontinued in 2006. impacts of Bti 11 Potential Effects of Bti to Human Health Bti poses little threat to human health through either handling the product directly, or being exposed to it indirectly, such as during a municipal mosquito control program. Bti is essentially non-toxic to humans, so there is minimal concern for human health effects from Bti when used according to labeled directions (EPA 2002). The most likely routes of exposure for the general public to Bti are oral, dermal, and inhalation. Slight to moderate skin irritation and eye irritation has occasionally been observed in product tests, which may be attributed to other ingredients in the product formulation (EPA 1998). Observed eye irritation is often associated with dry, anhydrous forms of the product and may be due to physical irritation effects as might be caused by sand or drying agents rather than toxicity of the product. Product labeling require- ments regarding these effects are in place to minimize the risk of skin or eye irritations. The acidic conditions in human stomachs do not activate Bti toxins. Studies have shown that even if Bti spores are ingested or inhaled by humans, they are eliminated without any adverse health effects (Health Canada 2001). To date, no known mammalian health effects have been demonstrated in any infectivity / pathogenic- ity study of Bt-based products (EPA 1998). Potential Impacts to Water Quality from Bti Bti is not expected to impact public drinking water supplies. Bti is a naturally-occurring soil bacterium that readily breaks down in the environment through exposure to sunlight and microorganisms. The potential is minimal for Bti to enter groundwater or other sources of drinking water, and the bacterium does not proliferate in aquatic habitats (EPA 1998). Bti is not screened for in drinking water supplies as a potential indicator of microbial contamination or as a direct pathogenic contaminant (EPA 1998). Bti is suitable for application to irrigation water and any other water supplies, except for ﬁnished drinking water. Low perco- lation rates through soil and municipal treatment of raw water supplies used for drinking water reduce the possibility of exposure to Bti through drinking water sources. As a safety precaution, labeling requirements must state that Bti should not be applied directly to treated drinking water reservoirs or drinking water receptacles. Bti does not readily move from an application site and is unlikely to percolate to groundwater (National Pesticide Telecommunications Network [NPTN] 2000). No restrictions have been issued for use of this material around bodies of water (EPA 1998). Potential Effects to Water Quality from the Manufacturing Process of Bti Bti is grown commercially in large fermentation vats under a controlled environment. The material is then concentrated, dried, and formulated for use as a liquid or a solid. In addition to the active ingredient Bti, other ingredients are used to make the ﬁnal product. These other ingredients are termed “inert” ingredi- ents, as they do not have direct pesticidal activity against the target pest. Product manufacturers consider the inert ingredients proprietary information. Unless an inert ingredient is determined to be highly toxic, it is not required by law to be identiﬁed by name or percentage on the product label, however, the total per- centage of inert ingredients must be declared (NPTN 2000b). No toxic materials or hazardous chemicals (that is, heavy metals) are used in the manufacturing process of Bti (Whitman 2003). Some strains of Bt, of which Bti is a variety, have the potential to produce various undesirable toxins during the manufacturing process, however, quality control testing requirements are in place to prevent these toxins from appearing in products (EPA 1998). The disposal of any residual material from the manufacturing of Bti is not expected to have any environmental impacts due to the non-toxic nature of the ingredients used in the process. Ef- ﬂuent from the Bti manufacturing plant may contain Bti or fermentation byproducts; discharges of this efﬂuent to waters of the state would be regulated under the National Pollutant Discharge Elimination Sys- tem permit process for discharges from the plant to ensure compliance with state water quality stan- dards. Managing Flood-Irrigated Lands on Open Space and Mountain Parks lands Flood-irrigated lands, identiﬁed by the city of Boulder, were mapped and surveyed for the presence of mos- quito breeding habitats. Operators on these lands will be contacted to discuss their plans for irrigation and irrigation frequencies. Irrigators will be encouraged to reduce the water volumes applied during ﬂood irri- gation to maximize agronomic uptake and minimize the amount of standing water on these lands follow- chapter two larval mosquito management ing irrigation events. Mosquito breeding habitat would be minimized by reducing the amount of standing water. These areas will be surveyed throughout the mosquito breeding season and larval treatments would be applied when the targeted Culex species are identiﬁed. Other Larval Mosquito Control Methods Two additional larval control techniques were considered but are not preferred at the current time. How- ever, theses techniques were not rejected as options for future management should ecological and/or risks to human health conditions change. They include application of the insecticide Bacillus sphaericus and manipulation of mosquito habitats. These methods are discussed below. Application of Bacillus sphaericus Bacillus sphaericus (Bs) is a bacterium that occurs naturally in soil and contains protein crystals and living spores with larvicidal abilities similar to Bti. The toxin is active only against the feeding larval stages and must be partially digested before it becomes activated. During digestion, larval enzymes dissolve the crystals in to protoxins, which are smaller crystals. These protoxins then paralyze the gut and break through pores in the gut wall within a few hours to invade the body cavity and multiply. The mosquito larvae will die within 48 to 72 hours allowing predators a minimum of 2 days of the normal 4 to 5 day predation window. Bs adversely affects larval stages of insect species in the Order Diptera, Suborder Nematocera, Family Cu- licidae (mosquitoes) (Florida Coordinating Council on Mosquito Control [FCCMC] 1998). Bs is speciﬁc in causing mortality to mosquito larvae. Culex species are the most sensitive to Bs. In contrast to Bti, Bs is virtually non-toxic to black ﬂies (FCCMC 1998). Mammals and other non-target species are unaffected by applications of Bs. The application of Bs is an option for control of WNV, but is not proposed for use under this plan. It is similar to Bti in that it is a bacterium, but the differences are signiﬁcant. Bs is desirable because, like Bti, it kills the mosquito larvae, and ﬁeld technicians can see results within two days of treatment. Bs also has demonstrated efﬁcacy in controlling mosquito larvae in highly organic aquatic environments, including sewage-waste lagoons and septic ditches (FCCMC 1998). However, certain factors make this product undesirable for use in the city of Boulder. First, the residual for Bs in water is 2 to 4 weeks before retreatment is necessary (FCCMC 1998). Bs has the ability to release fresh spores into the water column and recycle itself offering residual control, but also having extended affects to nontarget organisms. Second, mosquitoes have been shown to develop resistance to Bs, which reduces its effectiveness (Nielsen-LeRoux and Silva-Filha 2003). Finally, similar to Bti, part of the food chain is tem- porarily removed, potentially affecting predators by removing a source of food. Eggs that are laid within 4 weeks of treatment still have the potential to be affected by Bs, causing a break in the food chain that lasts longer than with Bti. Mosquito Habitat Manipulation Manipulation of mosquito habitats is another option for control of WNV. Manipulation involves water man- agement strategies to eliminate mosquito breeding areas and can include activities such as ﬁlling in or improving drainage in certain areas, or pumping water out of low-lying areas. Manipulation can perma- nently change the function of the mosquito habitat and can severely affect the ecological integrity of the wetland ecosystem. This method of mosquito larvae control would be implemented only on nonregulated wetlands under this plan. Techniques Considered But Not Recommended for Larval Mosquito Control Three optional techniques for controlling larval mosquitoes were considered for use in this plan but are not recommended. These options include applying the insecticide methoprene, introducing predatory ﬁsh, and applying oils or monomolecular surface ﬁlms. These methods are discussed below. Application of Methoprene Methoprene is different from Bti and Bs because it is a hormonal insect growth regulator (IGR), not a bac- terium, 12 and it does not immediately kill the mosquito larvae (EPA 2002). The IGR is a copy of the juvenile chapter two hormone in the mosquito. The hormone prevents complete metamorphosis by disrupting the molting process and does not allow the larvae to develop into an adult causing the mosquito to die at the pupa stage (EPA 2002). Methoprene allows the larvae to remain in the food chain, but prevents the emergence of adult mosquitoes that bite and breed. The methoprene is added to the water and absorbed through the larval exoskeleton. Use of methoprene in wetlands poses two identiﬁed maximum potential impacts. First, it affects more nontarget species than Bti and Bs, including ﬁsh and aquatic invertebrates. Second, the residual time for methoprene in water varies depending on the form of the product used: 21 days (sand), 30 days (pellet), or 150 days (briquette) (MMCD 2002). This long residual time poses a signiﬁcant risk to the biological function of wetlands. Introduction of Predatory Fish Control of mosquitoes often includes introduction of minnows, such as Gambusia afﬁnis (mosquito ﬁsh), or a Colorado native, the plains killiﬁsh (Fundulus zebrinus). The top-wa- ter feeding minnows can consume approximately 100 mosquito larvae per day when they become adults. Their offspring begin feeding immediately after birth and they are able to have several gestations per season. Similar to Bti and Bs, stocking of predatory ﬁsh is considered a biological control. However, ﬁsh are less species-selective than are the two species of bacteria. Fish introduced to a wetland will eat mosquito larvae as well as all other palatable aquatic life in the wetland potentially having detrimental effects to nontarget species. Application of Oils or Monomolecular Surface Films The application of oils to water is not species speciﬁc (EPA 2002). Products containing min- eral oil such as Bonide Oil or Golden Bear Oil, or a monomolecular surface ﬁlm such as Agnique are allowed for limited use only approved on a case-by-case basis by the Colorado Division of Wildlife and the Colorado Department of Public Health and Environment (CD- PHE). Oils or surface ﬁlms are used to mainly treat mosquitoes in the pupal stage. Gilled aquatic insects are apparently not affected by oil treatments, but they are lethal to most surface-breathing aquatic insects or those that depend on a breathing tube. The oil causes them to suffocate. The monomolecular surface ﬁlms are effective by reducing surface ten- sion on the water, which prevents larvae or pupae from hanging from the surface. This action causes them to drown. There is also the potential for ﬂying insects that land on the water to be impacted, but this has not been study comprehensively. These alternatives are not recommended for use by the city of Boulder, as they could se- verely affect the biodiversity and abundance of aquatic life within a wetland as well as alter the aesthetic appearance. These types of treatments must be closely monitored for effec- tiveness of eliminating the pupae and for affects to nontarget species. 13 larval mosquito management chapter two Larval Mosquito Monitoring Plan As of 2005, a majority of potential larval breeding sites have been identiﬁed, surveyed, and mapped. Not all potential habitats necessarily breed mosquito larvae and further, not all habitats that breed mosquito larvae produce Culex. However, certain sites have bred Culex larvae consistently when surveyed or received one or more Bti treatments. Therefore, it makes sense to differentiate between habitats and focus initial surveillance efforts only at the sites where Culex mosquitoes have historically occurred and/or where Culex mosquitoes are more likely to occur at some point during the season. Based on data collected from 2003-2005, 488 sites have been categorized as follows: 14 larval mosquito management chapter two Figure 2-1 Larval Breeding Site Locations and Categorization larval mosquito management Category I - Vector larval breeding sites: All sites where Culex larvae have been found breeding Category II - All mosquito larval breeding sites: All sites where only nuisance mosquito larvae have been found breeding (to date) Category III - All potential larval breeding sites: All potential mosquito breeding sites that have not been found breeding any type of mosquitoes (to date) In general, Boulder’s mosquito season occurs May through September, while the peak season for Culex breeding is June through August. Given this ecology, the following is a table of when and where mosquito management will occur, assuming a ‘normal’ mosquito year: Management Actions May June July August September Category I Vector larval breeding sites X X X X X Category II All mosquito larval breeding sites X X X Category III All potential larval breeding sites X Table 2-2 Annual Baseline Larval Mosquito Monitoring and Control Plan Larval monitoring and needed control will occur at all sites where Culex larvae have been found, during any of the three previous years of monitoring, once per week during the entire mosquito season. Monitoring and any necessary control will also occur, once per week, at all mosquito larval sites that have ever been found to be breeding non-Culex mosquitoes during the height of the Culex breeding period (June-August). Monitoring and any necessary control at all remaining mapped potential larval breeding sites within or near city limits will occur once during the peak season (beginning in the ﬁrst week of July) as a measure of quality control. Weather will also determine the frequency at which sites will be monitored. If a site is found to be dry, that particular site will not be checked again until it rains or is irrigated. As the season progresses sites may be moved to other categories. For instance, if Culex is found in a Cate- gory II site, that site will be treated and redesignated as a Category I site for the remainder of that season and for following seasons. Similarly, if non-Culex mosquito larvae are found in a Category III site during the check in early July, it will be redesignated as a Category II site and checked more frequently for the remain- der of the season and will remain a Category II site for the following seasons. The above plan is designed for maximized vector control, as pre-peak and post-peak season Culex larval control will likely reduce Culex adults from emerging later in the season or even the following year (Culex can overwinter). Monitoring and control in Category II sites during the heightened Culex breeding period and in Category III sites during peak Culex activity (as particular precipitation and temperature conditions could produce sites hospitable to Culex in places where they have not yet been observed) will further en- hance WNV prevention and early detection and provide quality control as a measure of success in detecting ﬂuctuating sources for Culex. Thresholds for Increased Larval Vigilance and Management The plan also allows for maximum ﬂexibility in monitoring and control, should a combination of thresholds be met at any point in the season that may warrant increased vigilance. Thresholds for increased monitor- ing between site categories include: • A signiﬁcant percentage (~50%) of vector sites that are breeding Culex larvae in May, • Early detections of WNV in area adult sentinel traps, • High or rapidly increasing adult mosquito populations in general, and • Early or rapidly increasing cases of WNV in humans and/or birds. 15 chapter two larval mosquito management Below is the same table that demonstrates what increased management actions may be taken in a high mosquito and/or WNV year, where _ represents an above average to high mosquito year and _ indicates an WNV epidemic year (such as in 2003). Management Actions May June July August September Vector larval sites X X X X X All mosquito larval sites _ X X X _ All potential larval breeding sites _ _ X _ _ Table 2-3 Increased Monitoring and/or Management Plan for Larval Sites Larval Monitoring Protocol To inspect a project site a plastic dipper cup with a 3-foot wooden handle is used to collect water from the site. Each sample (dip) is closely examined for mosquito larvae presence. If mosquito larvae are present, an eyedropper is used to collect a representative sample for future species identiﬁcation. A representative sample consists of mosquito larvae with all the various instars (life stages) that are present. The majority of the sites have poor open water habitat in the center and good habitat around the perimeter of the site. At these sites, the dipping effort is completed using a linear approach (walking around the perimeter and sampling the margins). Some sites are small (1 acre or less) and have good habitat throughout the site. At these sites the dipping effort is completed using surface area guidelines where the entire site is methodi- cally sampled. Using the linear approach, sites 1 acre in size and less are dipped approximately every 10-20 feet; sites 1 to 10 acres are dipped approximately every 50 to 100 feet, and sites greater than 10 acres are dipped ap- proximately every 200 to 500 feet. Using the surface area approach, sites 1 acre in size and less are dipped approximately every 10 to 20 square feet. Since each project site varies in size, physical characteristics, and changes as the season progresses (e.g., becomes drier, wetter, increased vegetation), there are ﬁeld adjust- ments made during the season concerning appropriate number of dips. For example, at a very small site (less than 1/10 acre), the site may be dipped every 1 square foot to get good coverage. At the beginning of the season, all sites are monitored consistently. During the peak season (July through August), the sites are categorized into high and low priorities due to heightened risk of WNV and time effectiveness. Larval Control Protocol Larval mosquito control methods employed by the city of Boulder are designed to reduce the potential of WNV. The program’s focus for larval control is to identify if Culex species (primarily C. tarsalis and C. pipi- ens) were present before initiating control efforts. The threshold for larval control is presence of the vector species. The method allows for pest mosquitoes and non-biting mosquitoes to persist in the environment if vector species are not present. The approach requires more frequent monitoring but results in substan- tially less treatment of (and therefore less potential adverse impact to) wetlands and other mosquito breed- ing habitats. Unlike a large-scale broad-spectrum mosquito control program, where presence of any type of mosquito larvae triggers treatment, the presence or absence of vector species has to be determined before site-speciﬁc larval treatment occurs. Finding and documenting consistent vector breeding sites is an important component for the program because it creates a pattern that can be monitored and systemati- cally controlled. The objective of larval mosquito control is to prevent the need for adult mosquito control spraying, which is much less effective than larval control. To accomplish this more effective protocol with as little impacts as possible, it is necessary to have a team more skilled than is typically necessary for mosquito control efforts. It is likely that the contracted service that performs the monitoring and control of sites will need to maintain a strong biological staff during the season including a core team of professional aquatic biologists, wetland scientists, and mosquito control 16 specialists, all with aquatic invertebrate identiﬁcation skills. This core team should likely be supported with chapter two a seasonal crew with natural resource and biology backgrounds and experience in mos- quito larvae and adult monitoring/control. The contractor and/or city of Boulder should use geographic information systems (GIS) ArcView software to compile wetland areas, mos- quito habitat, adult trapping locations, etc. to aid the larval mosquito monitoring and control creating a database for quick access and queries. A city wetland permit is needed for larval control when using a pesticide. See Appendix C for a copy of the current wetland permit and procedures for renewal. 17 larval mosquito management chapter two Map potential breeding habitats and categorize sites based on vegetation type, water retention and potential mosquito habitat Larvae collected? Culex species larvae present? Inspectors check for larvae Identify potential breeding habitats Collect representative sample of larvae and fill out label and Field Form 1 (FF1) Fill out Field Form 1 (FF1) and enter into database NO control needed. Enter information into database Field I.D. larvae or transport larvae samples to I.D. lab I.D. species of larvae and fill out lab form See Larval Control Flowchart YES NO NO YES LARVAL SURVEILLANCE FLOWCHART Figure 2-2 Larval Monitoring Flowchart 18 larval mosquito management chapter two Larvicide Application Methods The application of Bti is the approved method for larval mosquito control because it serves the greatest public need. Adverse impacts to areas being treated are minimized by apply- ing Bti at the recommended concentrations, and all treatment areas are posted with bright yellow city pesticide notiﬁcation signs before Bti is applied. The usual application rate used for Bti is 5 pounds/acre or 0.2 acres treated per 1.0 pound of Bti. The application rate seems to provide 100 percent control in the majority of treat- ments. Applicators use appropriate personal protection equipment (PPE) when applying the Bti including gloves and ﬁlter masks. Larvicides are applied in accordance with regulations set forth by the city of Boulder and other governing bodies. Recommendations for applying larvicide are provided to city ofﬁ- cials and include the type and amount of material to be used on a case-by-case basis. Lar- vicides are applied by ground crews where necessary. Currently, there is no plan to apply larvicide with aerial equipment. Larvae are collected after treatment to evaluate the efﬁ- cacy of control operations. Control Successful? YES NO Return to Top LARVAL MOSQUITO CONTROL FLOWCHART DAY 2 DAY 2 DAY 2 DAY 3 DAY 3 OtterTail and City officials make determination to perform larval control OtterTail performs control (Application of Bti) Fill out Larval Control Field Form 2 (FF2) Post-treatment larval inspection Culex species larvae present (from Larval Surveillance Flowchart) Fill out FF1 and enter information into database Figure 2-3 Larval Control Flowchart adult mosquito management plan 19 Bti Handling and Spill Control Bti is spread on treatment areas by hand or by using hand seeders and power spreaders. When a site is identiﬁed as requiring treatment, the seeders are ﬁlled with the appropriate amount of control material, as indicated on the label, is measured out for the site and then applied. Field personnel wear appropriate pro- tective gear, including goggles, gloves, dust masks, and long sleeved clothes. Seeders and spreaders are ﬁlled in the ﬁeld vehicles to minimize the chance for spills. In the event of a spill of controlled material (Bti) that could result in signiﬁcant injuries, signiﬁcant property damage, or environmental threat, the following guidelines are followed. • Report any spill immediately to the ﬁeld crew leader • Be familiar with the spill response kit • Conﬁnement and cleanup of material 1. Avoid direct contact with skin and avoid dust inhalation 2. Recover the product, place into appropriate container for disposal 3. Ventilate and wash the spill area, if necessary 4. Dispose of product in accordance with federal, state, and local regulations • Notify city staff and other agencies as appropriate CHAPTER 3: ADULT MOSQUITO MANAGEMENT Adult Mosquito Monitoring Plan Proper monitoring of adult mosquitoes, which includes testing for the presence of WNV, is important in guiding prevention and control because it can provide information on the potential threat to residents and can indicate areas where efforts to eliminate mosquitoes should be targeted. At present there are 23 trap locations set up within and near city limits; 16 are checked and maintained by city of Boulder contractors, 4 by Boulder County (or its contractor), and 3 by University of Colorado. Figure 3-1 shows approximate adult trap placement around the city. The following table shows the city’s plan for checking its traps during mosquito season: Management Actions May June July August September Adult trap monitoring (16 traps) * X X X * Table 3-1 Adult Mosquito Monitoring Plan * indicates other agency monitoring All city traps are monitored weekly for WNV in adult mosquito populations during the peak of Culex activ- ity. The adult monitoring plan does not cover the entire length of mosquito season (or potential Culex breeding period), though forewarning of especially early or late season Culex activity in adult traps can be gathered from contacting the CDPHE and BCPH on a regular basis (BCPH usually maintains a total of 41 traps within its mosquito control district). City of Boulder staff or its contractor may begin monitoring its adult traps for WNV presence earlier (May) or later (September) than planned as shown above if data from partner agencies indicate that there are early, rapidly increasing, or high sustained levels of vector mosquito populations and/or early, elevated, or sustained cases of WNV present in humans and/or bird and mosquito populations. A continued and extensive communication network will serve as the best resource to make the most informed decisions on monitoring and control of WNV. This network involves city agencies, CDPHE, BCPH, Colorado University, regulatory agencies, and other bodies associated with monitoring of WNV. If areas are found to support adult Culex carrying WNV, additional traps may be set in those areas. Sweep net samples may also be taken in areas where large numbers of adult mosquitoes are observed to supple- ment the trap data. chapter three adult mosquito management plan 20 Figure 3-1 Adult Mosquito Trap Locations chapter three 21 adult mosquito management plan chapter three Adult Mosquito Monitoring Protocol Trap Site Selection Adult mosquitoes can dehydrate quickly during the daylight hours if they do not have a shady area to rest and escape the heat. Most mosquito species prefer to rest during the heat of the day in areas known as harborage areas. A mosquito harborage area is usually a shaded, wind-protected, moist area that is often near a source of water. Harborage ex- amples include groves of tall trees with a layer of shrubby undergrowth, dense bushes, tall live grasses, or under roof eaves and inside tires in residential areas. Adult mosquitoes will even collect in shorter grasses that are lush from frequent watering. The harborage sites for the project are important for long-term monitoring; therefore, the trap sites were chosen carefully. Staff worked with the BCPH to identify 16 adult trap loca- tions and the radius around each trap that could potentially be sprayed. The city cooper- ates with the University of Colorado and Boulder County in order to provide complete coverage for the city. The locations of the adult mosquito traps were chosen based on pro- viding thorough coverage of the entire city as well as cover areas where human cases oc- curred in 2003. A recommendation from the CDC is that adult traps not be placed close to larval breeding sites because newly hatched mosquitoes have not had a chance to become infected with WNV; therefore a lower infection rate may be obtained from the data than is actually present in the mosquito population. Trap Methods There are two different types of adult mosquito traps typically used to monitor adult pop- ulations, the gravid trap and the carbon dioxide (CO2) light trap. The CO2 light trap is used to capture a representative sample of the types and numbers of an area’s adult mosquito population. The gravid trap attracts adult female mosquitoes that have already collected a blood meal and are ready to lay their eggs. Both types of traps have been incorporated into the city of Boulder’s WNV monitoring program. To capture the most representative sample of adult mosquitoes in an area, adult CO2 light traps are set overnight to collect live adult mosquitoes throughout the season. The traps are based on the principle that most adult mosquitoes are attracted to light, CO2, and heat. The CO2 light trap collects adult female mosquitoes that are attracted to mammals. Therefore, the CO2 trap indicates when the vector mosquito species are no longer feeding solely on birds and have turned to mammals as their alternate blood meal. This is one of the ﬁrst indicators that WNV is likely to be transmitted to people through the vector mos- quito (assuming the trapped vector mosquitoes are found to be carrying WNV). The trap consists of a plastic insulated bucket with a battery casing hanging directly below the bucket and a ﬁnely meshed net hanging below the battery at the very bottom. The entire device is placed on a tree branch about 5 to 7 feet off the ground by a small chain or rope letting the bucket and net hang free. The bucket is ﬁlled with 2 to 3 pounds of commercial dry ice (CO2) and holes at the base of the bucket allow a slight amount of CO2 to leak out as an attractant. The battery runs a small fan and light positioned above the net. The light provides further attraction and once the mosquitoes are near the light, they are sucked down into the net and trapped by the downward force of the fan. In the morn- ing, the mosquitoes are removed and then frozen to aid in identiﬁcation. Once identiﬁed, the mosquitoes are then sorted by species and vector mosquitoes are submitted to CDPHE for WNV testing. The gravid trap mimics sources of mosquito breeding habitat and collects gravid female mosquitoes. The trap consists of a plastic tub with a fan unit and net above it. The device is placed on level ground in a mosquito harborage area. The plastic tub is ﬁlled approxi- mately halfway with an odorous attractant that is obtained from a hay infusion (a fer- mented mix of water, manure, and hay that mimics stagnant, organic water that is highly attractive to gravid female Culex mosquitoes, particularly C. pipiens). Above the tub is a fan unit with a ﬁnely meshed net attached to it. As the mosquito ﬂies along the surface of the attractant to lay its eggs, it is sucked up by the fan and into the net. The net is col- lected the next day and the mosquitoes are frozen to aid in identiﬁcation. Once identiﬁed, the mosquitoes are then sorted by species and vector mosquitoes are submitted to CDPHE for WNV testing. Pooled Traps Because of limited resources of all area agencies involved in WNV management, vector mosquitoes from the CU and the city of Boulder adult traps are pooled before they are submitted to the CDPHE for testing. It is expected that this method will be used throughout the season until a pooled sample proves positive for WNV. In this case, traps will then be submitted and tested individually during the next trapping cycle in order to try to deter- mine a general area where WNV may occur. WNV Detection Initial or a single detection of mosquito-borne pathogens in mosquito or avian populations within Boulder will be communicated to the City Manager. When approved, a press release will be drafted to notify the public of the recent ﬁndings. Monitoring will continue with the following added activities: 1. Adult mosquito trapping will begin, or will be increased, in the area of concern if ad- ditional monitoring data are required. 2. Larval monitoring will be enhanced in affected areas if needed. 3. Laboratory testing of adult mosquitoes will be a priority in affected areas. Data from these additional collections will aid in evaluating the extent of pathogen trans- mission and mosquito populations and be used to guide control measures, if applicable. In addition to the above actions, persistent detection of WNV in vector mosquitoes or in non-avian vertebrate populations, such as horses, within Boulder (County) will prompt the following control measures to be considered: 1. Ground application using backpack applicators of adulticides to immediate areas of concern in harborage areas where large numbers of adult mosquitoes are concentrated would be recommended. Truck-fogging would not be recommended in these areas. 2. Application by truck-mounted fogger of adulticides to broader areas, based on monitor- ing data. Adult Mosquito Control - Contingency Management Adult mosquito control agents (adulticides) are materials applied for control of adult mos- quitoes. Control of adult mosquitoes is not an assumed part of this plan, but is included as a contingency measure if monitoring suggests that the level of WNV activity poses a sig- niﬁcant threat to human health. The products that would be used in this event are dis- cussed below. The data on spraying for adult mosquitoes shows a range of efﬁcacy, from 10% to 80%, depending on the amount of vegetation, environmental factors, and the mosquito species. Entomologists at the Center for Disease Control (CDC) report that the percent reduction in Culex populations in recent studies is 30-35%. Other mosquito species are killed at higher rates. Most communities and mosquito control districts that conduct spray programs use the number of mosquitoes as a guide in determining spraying needs. City of Boulder staff coordinated BCPH and the CDC to reﬁne a spray protocol for the city of Boulder for an emergency adult vector mosquito spraying program. 22 adult mosquito management chapter plan three adult mosquito management plan Figure 3-2 Adult Mosquito Monitoring Flowchart 23 Adults? C. tarsalis or C. pipiens present? West Nile Virus present? YES YES YES NO Fill out FF1 Transport target species to WNV lab for testing Enter information into database Enter information into database Fill out Field Form 1 (FF1) Prepare samples and transport to I.D. lab (fill out labels) Calculate WNV infections rates, issue press release regarding increased WNV activity, and evaluate possible need for adult control. (If adult control needed, see Adult Control Flow Chart) Gravid traps CO2 traps Sweep Nets Identify mosquito harborage locations ADULT SURVEILLANCE FLOWCHART Map mosquito harborage locations Inspectors set traps in representative habitat to collect adults NO NO chapter three adult mosquito control 24 Preferred Adult Control Agents The adulticides recommended for application under the adult mosquito control contingency plan are known as synthetic pyrethroids. Synthetic pyrethroids are synthesized derivatives of naturally occurring pyrethrins, which are taken from pyrethrum, the oleoresin extract of dried chrysanthemum ﬂowers. The three speciﬁc pyrethroids that could be implemented as a contingency measure for adult mosquito control are permethrin, resmethrin, and sumithrin. A label and MSDS sheet adult control agents can be found in Appendix B. Potential Impacts of Synthetic Pyrethroids These products cause rapid knockdown of adult mosquitoes and are typically mixed with a synergist com- pound, such as piperonyl butoxide, which enhances the effectiveness of the active ingredient. They exhibit low mammalian toxicity, degrade rapidly in sunlight, leave little or no residue, and do not bioaccumulate in the environment. Dosage rates can be low to control mosquitoes. These products are applied in small quantities per acre, referred to as ultra-low volume (ULV) application. ULV delivery techniques minimize environmental impacts at the same time they effectively manage populations of adult mosquitoes. The city or its contractor will monitor the application of the adulticide to ensure compliance with all regulations and requirements stated by the EPA, State of Colorado, and city of Boulder. Synthetic pyrethroids are effective in killing mosquitoes, gnats, biting and non-biting midges, black ﬂies, and other biting ﬂies. These insecticides readily bind to soil and other organic particles; however, they are degraded by sunlight in water and on soil surfaces. Pyrethroids are extremely toxic to honeybees. Product labels specify requirements for minimizing effects to bees (Bayer Environmental Sciences [BES] 2002), though care should be taken to not apply these products in crops or weeds where foraging by honeybees may occur (BES 2002b). According to the EPA, Pyrethroids can be used for public health mosquito control programs without posing unreasonable risks to human health when applied according to the label. However, they are considered to pose slight risks of acute toxicity to humans, and at high doses, pyrethroids can affect the nervous system. According to the Center for Disease Control, People who are concerned about exposure to a pesticide, such as those with chemical sensitivity or breathing conditions such as asthma can reduce their potential for exposure by staying indoors during the application period (typically nighttime). Pyrethroids are extremely toxic to aquatic organisms; however, recommended manufacturer dosage rates control the toxicity of these products to non-target species. Lobster, shrimp, mayﬂy nymphs, and zooplankton are the most susceptible non-target aquatic organisms (Mueller-Beilschmidt 1990). Some permethrin based mosquito control prod- ucts direct the user not to apply the product within 100 feet of lakes or streams. This restriction or “buffer zone” was put on many permethrin labels out of concern for aquatic toxicity that might result due to run- off from agricultural sites, not as a result of an assessment of risks associated with the signiﬁcantly lower concentrations of the active ingredient involved in ULV mosquito control applications. Resmethrin product labels state “Avoid direct application over lakes, ponds and streams” (emphasis added), but the same labels state that vegetation “around stagnant pools, marshy areas, ponds and shorelines may be treated” and there is no buffer zone requirement (EPA 2005). Thresholds for Initiating Adult Mosquito Control Adult control activities that include spraying of pesticides will be the ﬁnal option to pursue in an attempt to reduce the threat of WNV. Spraying of pesticides in an urban environment is the most costly, inefﬁcient, and environmentally unfriendly procedure in an IMM (Integrated Mosquito Management) program. Re- sponsible IMM practices include extensive larval control with a contingency plan for adults. Theoretically, the ideal larval control plan would eliminate the need for any control of adults. However, the rapid develop- ment of mosquitoes from egg to adult and the persistent nature of breeding in an extensive variety of stagnant water bodies make complete elimination impossible. The ﬂight of C. tarsalis can range as far as 20 miles. Although it is rare for C. tarsalis to ﬂy 20 miles, it is possible that mosquitoes outside the city limits would migrate into Boulder. Therefore, a plan for control of adults is necessary as a contingency. Adult control thresholds for disease vectors are much harder to establish and justify compared to larval thresholds. Because the adult mosquito is no longer in a contained aquatic environment, adult control is chapter three 25 adult mosquito controclhapter three not nearly as effective. Adult mosquitoes will often vacate an area until the adulticide evaporates or settles to the ground. Adulticides also have more impact on non-target or- ganisms compared to larvicides. Final recommendations on adult control activities will weigh heavily on recommendations from the city of Boulder management staff, CDPHE, BCPH, CDC, and EPA. Among the thresholds established for implementation of adult mosquito control activities is ﬁnding WNV in C. tarsalis or C. pipiens adult females. Meeting or exceeding these thresholds does not directly correlate to spraying pesticides every time WNV is discovered in adult mosqui- toes. Control for adult mosquitoes will be determined on a site-speciﬁc basis. The presence of mosquito-borne pathogens in Boulder, if detected, will prompt one or more responses or interventions. These interventions can range from continuing existing routine monitoring to, in worst-case scenarios, large-scale application of adulticides. Mon- itoring data will be used to assess the risk of an outbreak of human disease and the need to apply pesticides in a limited and targeted area to control adult mosquitoes. The control response will depend on a combination of thresholds being met that include, but are not limited to: • the overall intensity and persistence of the WNV activity in adult Culex mosquitoes, hu- mans, birds, and non-avian vertebrates • the proximity of WNV activity to human populations within the city • the time of year • vector index level • seasonal climate Explanation of Mosquito Infection Rates and the Vector Index The CDC encourages surveillance programs to routinely incorporate a more informative index of relative virus activity, the virus infection rate (IR), into their mosquito-based evalu- ation of local virus activity patterns. At the county level or below, weekly tracking of mos- quito IR can provide important predictive indicators of transmission activity levels associ- ated with elevated human risk. Estimates of the IR are usually presented as the number of infected mosquitoes per 1,000 tested. The model used by the city of Boulder to calculate the virus infection rate, is called the Maximum Likelihood Estimation (MLE) and is the model approved and being used by public health ofﬁcials and epidemiologists across the country, including the Boulder Coun- ty Public Health Department. An index, based on the vector MLE and mosquito populations, was applied to the 2003 human WNV case number data by OtterTail and the City of Boulder to determine a single number that would indicate the potential need for adult mosquito control measures. Dur- ing this process, they determined that 0.75 would have provided an early warning of the pending human health epidemic (See Figure 3-3). To calculate the index, the number of Culex species mosquitoes is multiplied by the calculated WNV infection rate of the vector mosquitoes. OtterTail and the City’s proposed index rate of 0.75 was discussed with CDC and BCPH staff and approved by the Boulder City Council as the critical level that would trigger adult mosquito control. The index was developed by combining the data for all the traps in 2003. Although it would have been preferable to use this on an individual trap basis, this was not possible in 2004 due to the mathematical inability to calculate infection rates on one sample. There- fore, the index was used simply as a city-wide early warning system based on the average of all the city traps. The index is now being used, in combination with other thresholds, as an additional tool to aid in the decision making process for the possible need of any adult control activities. 26 adult mosquito controclhapter three Adult Mosquito Control Protocol There are two general strategies for mosquito adulticide applications, large-scale fogging and spot spray treatment. The ﬁrst and most expensive option is to fog large areas to at- tempt to signiﬁcantly reduce the number of adult mosquitoes in a targeted area. The effort could include many types of application methods: ground individual backpack units, fog- gers on ATV’s, foggers on trucks, and aerial applications. To use only one method, such as fogging with a truck-mounted unit, would be far less effective than using multiple meth- ods. However, a full-scale assault could undoubtedly reduce the adult mosquito popula- tions but the process could use an entire season’s budget in less than a month. Also, the main purpose of a large scale fogging approach is to keep the adulticide material airborne as long as possible without it evaporating. To keep the adulticide airborne a certain droplet size is needed and only expensive adulticiding equipment can do this accurately. The ef- fectiveness of the large scale fogging effort will be compromised if the control company does not have somewhat of free range of the city area to perform control. Public concerns or the majority of residential areas on a no-spray list will make effective, widespread con- trol almost impossible. The second option is to spray individual harborage areas, which is called spot treatment. This was the method used at the Boulder Reservoir in 2003 (the only adult spraying event that has occurred for WNV to date in the city of Boulder). Treating the harborage areas where adult mosquitoes are resting in high concentrations allows more mosquitoes to come in contact with the adulticide and uses a lower, focused amount of adulticide material. Each harborage area has unique characteristics and circumstances. Some areas can be controlled effectively with manual removal of the mosquito harborage habitat such as mowing long grass and removing vegetative understory; other areas can only be controlled effectively by spot spray- ing adulticides. After treatment a post check adult collection is performed to determine ef- fectiveness. Spot treatment has many positive aspects. First, it helps to identify possible overlooked mosquito breeding sites and areas where larval control should be focused. Secondly, spot treatments are (publicly) lower proﬁle than large-scale operations with much less adulticide material being used in the environment. Also, spot treatment potentially kills the same or more mosquitoes than fogging because the mosquitoes are concentrated in smaller areas. Figure 3-3 Vector Index adult mosquito control 27 Adult mosquito control would occur in the evening when mosquitoes are most active with hand-held spray units and truck-mounted fogger units. WNV No-spray List City residents may opt-out of the adult mosquito spraying program. The city of Boulder ‘s Ofﬁce of Envi- ronmental Affairs maintains a database of city residents who have called, emailed, or written letters re- questing that their property be skipped if adult control is necessary in their immediate area. A list of regis- tered addresses will be provided to the contracted service, who will in turn avoid spraying within 50 feet of the parcel boundaries. In many instances, this no-spray buffer affects neighboring properties, regardless of their interest in participating in the adult control program. As of 2005, 586 private parcels are registered on the no-spray list. In some areas, particularly more dense- ly occupied residential areas within the city, the no-spray zone covers a majority of a block or neighbor- hood. This presents real challenges for control, should a WNV event occur nearby that necessitates adult spraying. Each year, notiﬁcation cards are sent to registered addresses notifying them that their address is included on the no-spray list. No action is necessary for them to remain on the list from year to year. However to remove an address from the no-spray list (and become part of the spray program), residents must call the city’s WNV hotline (303-441-4004) or email the city’s WNV program by visiting www.environmentalaffairs.com. Precautions and Notiﬁcation Prior to Control There may be restrictions on or cancellation of planned outdoor evening activities or recommendations to close recreational areas. The public will be notiﬁed 48 hours in advance of the schedule for application of adulticides, potentially through reverse 911 calls in the affected area, which will allow time to take any necessary precautions to reduce exposure to the pesticide. An informational brochure will be distributed to the public who reside within a 1/2 to 1 mile radius of the epicenter where the WNV pathogen is detected. The brochure will contain recent ﬁndings and protective measures to be taken. Before control of adult mosquitoes begins, information on pesticides and their possible adverse health ef- fects will be provided to physicians and other health care providers, and hospital emergency departments. This information will include product information on pesticides, Material Safety Data Sheets, and other information relevant to identifying possible exposure to pesticides. Calls received by the Colorado Poison Control Center will continue to be monitored during pesticide spraying and will be forwarded to the Colo- rado Registry for Pesticide Sensitive People for possible follow-up and inclusion in the registry. Information will be distributed at least 24 hours in advance through the media, the city website, IPM hot- line, and pertinent city and community organizations. Control measures will be monitored and assessed for potential environmental and health effects through several means, including pre-application and post-application environmental sampling and complaints of exposure to pesticides received. Sampling will include pre-treatment and post-treatment checks using adult mosquito traps. Specimens will be collected more frequently to evaluate the efﬁcacy of the control measures. Example of Adult Mosquito Spraying Schedule All traps will be set on Tuesday night and checked Wednesday morning. Based on information from mul- tiple thresholds, city ofﬁcials would make the decision that emergency adult control is needed. Among the thresholds observed, in this example, are unusually high trap populations and infection rates from one of the traps. Therefore, it is determined that a one-mile radius would be sprayed around this trap. Two cycles of spraying would automatically occur, one on Monday and one on Thursday (the night of the third day) as recommended by the CDC. If the thresholds are still being met, including the information in the data from the post-spraying mosquito trapping, another spray event (two cycles) would occur in the next week. If the combined thresholds suggested that the threat of WNV was still high, spray events would continue until the threat levels fell. chapter three communicatin plan 28 Timeline Example: Wed: Mosquito trap collected and mosquitoes sorted by species and sent to State of Colorado Laboratory for WNV testing. Fri: Data received from lab and infection rate and index calculated. Data from multiple thresholds lead the city to decide that an emergency adulticide application will take place; the following actions would be initiated: Sat: Staff contacts spray contractor and conﬁrms date for spraying (in the evening two days away). Residents in trap area notiﬁed, potentially by 911 callback, press release is sent out and information posted on city’s website. Sun: Notiﬁcation continues. Mon: The spraying would occur in the evening, assuming that environmental condi- tions are favorable for spraying (i.e. low wind speed, no precipitation). Pick-up trucks with ultra- low volume (ULV) sprayers would drive the streets in the designated area. They would have ﬂashing lights and would be identiﬁed as mosquito control equipment. The contrac- tor will have the addresses from the city’s “no spray list” and will shut off the sprayer upwind of these addresses. Tue: Post-spray adult mosquito trapping. Notiﬁcation repeated for spraying on Day 9 (Thursday). Wed: Continue notiﬁcation. Thu: The spraying operation described for Day 6 would be repeated. Fri: Post-spray adult mosquito trapping. Wed: Regularly scheduled adult mosquito trapping. DAY 1 & DAY 2 DAY 1 & DAY 2 DAY 1 & DAY 2 DAY 2 & DAY 3 DAY 4 & DAY 5 Control communicatin planchapter four CHAPTER 4: COMMUNICATION PLAN In 2004 a WNV communications plan was drafted in order to ensure accurate, timely and consistent communication to the public regarding the potential of WNV, personal protec- tion from the virus, and the city’s plan to test for and treat WNV-carrying mosquitoes. As a joint effort between the city of Boulder’s Ofﬁces of Public Affairs and Environmental Af- fairs, the plan is implemented in the spring and continues until the end of the mosquito season by October. Funding is managed by the city manager’s Ofﬁce of Environmental Affairs. Communication Guides Topics and departments that will guide communication include mosquito larvae identiﬁca- tion, Boulder County Public Health efforts, community input, city council/city manager di- rection, and prevention efforts. There are privacy concerns with regards to those members of the public who may contract the disease. Seasonal Guidelines Early/late spring: Staff/consultants hired, prevention and protection messages formulated and information outlets identiﬁed Early Summer: Prevention and protection messages launched; early results of monitoring and treatment data communicated; communication on potential for adult mosquito spraying Mid-Summer: Reinforcement of prevention messages; monitoring and treatment data continues to be communicated; notiﬁcation of adult mosquito spraying (if necessary) Late-Summer/early fall: estimate timeframe for end of mosquito season (depending on WNV presence and abundance during the season); monitoring and control activities slow or stop; data compilation begins Key Messages for Success Success of the WNV plan would mean few to no human cases of WNV, high vector larvae termination rate, and the avoidance of spraying adult mosquitoes due to the public’s com- mitment to self-protection and habitat control. In order to reach these goals, the commu- nication plan highlights the following four key messages to be used in all education and outreach materials: 1) self protection is the most effective way to prevent contracting WNV; 2) avoid WNV by avoiding mosquito bites; 3) clean up sources of standing, stagnant water to eliminate mosquito habitats; and 4) the public still has a responsibility to take personal precautions even if the city sprays for adult mosquitoes. To deliver these key messages, various methods have been employed to target speciﬁc audiences. 1. One identity/graphic that is used throughout materials – Example: The One Bite campaign, produced by Boulder County Public Health, provides the city of Boulder with posters and ﬂyers for distribution to the general public. The campaign materials con- tained information about personal protection using the “4 D’s” (DEET, Dawn and Dusk, Dress, and Drain) and testimonials from persons infected with WNV in the past. Posters are displayed throughout the city of Boulder, at Open Space and Mountain Parks trail- heads, Parks and Recreation facilities, libraries, senior centers and the Municipal Building to raise awareness about WNV in the Boulder community. 29 30 wnv mosquito management chapter plan four 2. Public meetings/open houses 3. WNV hotline (303-441-4004) – Example: The WNV hotline, started in 2004, continues to be a resource for city of Boulder residents. Callers are given information from a menu service and can leave a message for city staff. Most calls received are regarding addition or removal from the No Spray List or to report potential sources of mosquitoes. 4. Videotaped presentations; use on Web and for check-out 5. Web site with details, updates, and announcements. Example: The city of Boulder’s WNV website, www.ci.boulder.co.us/environmentalaffairs/ipm/2005_WNVs.html, contains sections for current WNV activity, frequently asked questions, the city’s mosquito control plan, program maps, a property checklist, and links to email the city with WNV questions and to join the mosquito spraying email list. 6. Advertising and public displays (as needed, especially for spraying) Example: Farmer’s market presence at least once/week from May through August 7. Media Relations – Example: periodic news releases about WNV activity and recommen- dations for preventing exposure to mosquitoes. 8. Channel 8 – update Boulder (airing starting in June) 9. Utility bill inserts – (April or May and possibly July) with extra printed for outreach dis- tribution City WNV Communication Team • Neighborhood and Public Relations Coordinator • Media Relations Coordinator • Council Communications Coordinator • OEA Outreach Specialist • Integrated Pest Management Coordinator wnv mosquito management plan 31 REFERENCES Agriculture Canada. 1982. Report of new registration: Bacillus thuringiensis serotype H14. Food Produc- tion and Inspection Branch. Ottawa, Ontario, Canada. Bayer Environmental Science. 2002. Permanone Ready-To-Use Insecticide Specimen Label. Montvale,New Jersey. 3 pp. Bayer Environmental Science. 2002b. Scourge Insecticide Specimen Label. Montvale, New Jersey. 3 pp. Center for Disease Control and Prevention. 2001. Epidemic/Epizootic West Nile Virus in the United States: Revised Guidelines for Surveillance, Prevention, and Control. U.S. Department of Health and Human Services, Fort Collins, Colorado. 103 pages. 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A review of the environmental impacts of the microbial insecticide Bacillus thuringiensis. Horticulture Research and Development Centre, Agriculture and Agri-Food Canada, http:// res2.agr.ca/stjean/publication/bulletin/bacillus_thuringiensis_ 4_e.htm. Accessed April 3, 2003. Leighton, F. A. 2000. Western Equine Encephalitis [Web Page]. Located at: http://wildlife.usask.ca/ bookhtml/arbovirus/arbowee.htm. Accessed on April 15, 2001. Merritt, R. W. and M. Wipﬂi. 1994. “Impact of Bti on non-target aquatic insects and trout.” Michigan State University, www.msue.msu.edu/msue/imp/modet/61893002.html. Accessed 04/17/03. Metropolitan Mosquito Control District. 2002. 2002 Field Operations Manual. Revised March 2002. Metropolitan Counties Government Center, St. Paul, Minnesota. 237 pages. Mueller-Beilschmidt, D. 1990. Toxicology and Environmental Fate of Synthetic Pyrethroids. Journal of Pesticide Reformation 10 (3):32-37. references wnv mosquito management plan National Pesticide Telecommunications Network. 2000. Bacillus Thuringiensis Technical Fact Sheet [Web page]. Oregon State University, Corvallis, Oregon. Located at: http://nptu.orst.edu. Accessed: April 17, 2003. National Pesticide Telecommunications Network. 2000b. Inert or “Other” Ingredients Technical Fact Sheet [Web page]. Oregon State University, Corvallis, Oregon. Located at: http://nptu.orst.edu. Accessed: May 5, 2003. Nielsen-LeRoux, C., and M. H. Silva-Filha. 2002. Bacteria: A Tool in the Integrated Control of Mosquito Vectors of Diseases [Web Page]. Located at:www.nri.org/IPMForum/ipmwd/issue7/7mossies.htm. Accessed on April 18, 2003. Soliman, E. No Date. California Encephalitis [Web Page]. Located at: www.emedicine.com/med/byname/california-encephalitis.htm. Accessed April 15, 2003. U.S. Environmental Protection Agency. 1998. Bacillus thuringiensis subspecies israelensis strain EG2215 Factsheet, www.epa.gov/pesticides/biopesticides/ingredients/factsheets/factsheet_ 006476.htm. Accessed 04/10/03. Webpage last updated 04/01/03. U.S. Environmental Protection Agency. 1998. Reregistration Eligibility Decision for Bacillus thuringiensis. EPA, Washington D.C. 156 pages. U.S. Environmental Protection Agency. 2002. Larvicides for Mosquito Control [Web page]. EPA Region 10. Located at http://epa.gov/pesticides/factsheets/larvicides4mosquitos.htm. Accessed: March 3, 2003. U.S. Environmental Protection Agency. 2005. Pesticide Registration Notice 2005-1 Notice to Manufactur- ers, Producers, Formulators, and Registrants of Pesticide Products. www.epa.gov/opppmsd1/PR_Notices/ pr2005-1.pdf, 2005. 15 pages. U.S. Geological Survey. 2002. Wild Birds Help Scientists Understand West Nile Virus [Web page]. Located at www.nwhc.usgs.gov/whats_new/fact_sheet/fact_westnile_res.pdf. Accessed April 10, 2003. 2 pages. Whitman, S. 2003. Personal communication [May 2 telephone conversation with S. Barker, Greystone Environmental Consultants, Greenwood Village, Colorado. RE: Manufacturing Process of Bti]. Public Health Products Specialist, Valent Biosciences Corporation, Laramie, Wyoming. 1 page. This West Nile Virus Mosquito Management Plan is comprised mostly of information presented in the following reports and plans: “City of Boulder West Nile Virus Mosquito Control Plan.” OtterTail Environmental, Inc. Colorado, July 2003. “City of Boulder West Nile Virus Surveillance and Control Report, 2003 Season.” OtterTail Environmental, Inc. Colorado, March 2004. “OtterTail Mosquito Control Field Manual.” OtterTail Environmental, Inc. Colorado, 2004. 32 references wnv mosquito management plan APPENDIX A: CITY OF BOULDER INTEGRATED PEST MANAGEMENT POLICY City of boulder integrated pest management policy can be found at: www.ci.boulder.co.us/environmentalaffairs/ipm/IPM%20policy%20rev%202002%20ﬁnal.pdf APPENDIX B: LARVACIDE AND PESTICIDE LABELS AND INFORMATION This appendix can be found at: www.ci.boulder.co.us/environmentalaffairs/documents/appendixb.pdf APPENDIX C: CONTRACTS AND PERMITS Contracted Services with City of Boulder The initial contract is executed and put into force for 1 year. The Contract is then eligible for annual renew- als for 4 additional years. These term limitations are due in part to Tabor and are not alterable. A ‘scope of work’ or ‘schedule of work’ that is redeﬁned from year to year is necessary for annual contract renewals. Renewals are handled by the requesting department’s contact in the Purchasing Department. Putting together an initial contract is a cooperative effort between the issuing department, the City Attor- ney’s Ofﬁce and Purchasing. Purchasing facilitates the bid process, execution of the contract and renewals of the contract. The City Attorney’s Ofﬁce provides the Contract Boiler and assists with language additions, etc. The issuing department administers the fulﬁllment of the contract terms with the contractor. A copy of the current contract and scope of work can be found at: www.ci.boulder.co.us/environmentalaffairs/documents/appendixc.pdf Permits A wetland permit is required for larval mosquito control using a pesticide in all regulated city of Boulder wetlands, as stated in the 1981 Boulder Revised Code, Title 9 Land Use Regulation, Chapter 12 Wetlands Protection (and amended by Ordinance No. 7338). The following is a link to the wetland ordinance. Section 9-12-12 covers the renewal requirements. www.ci.boulder.co.us/cao/brc/title9.html A copy of the current contract and scope of work can be found at: www.ci.boulder.co.us/environmentalaffairs/documents/appendixc.pdf 33 mosquito borne infectious diseases wnv mosquito management plan APPENDIX D: MOSQUITO-BORNE DISEASES THAT MAY OCCUR IN COLORADO There are currently four arboviruses found in Colorado that are transmitted by mosquitoes: WNV, Western Equine Encephalitis, St. Louis Encephalitis, and California Encephalitis. Arbovirus, which is short for arthro- pod-borne virus, is a group of viruses that are spread mainly by blood-sucking insects, such as mosquitoes. Encephalitis is an acute inﬂammation of the brain tissue. It can be caused by a variety of agents, but vi- ruses are the most common cause. The following chapter describes these viruses. Western Equine Encephalitis Western Equine Encephalitis (WEE) is found throughout North, Central, and South America. However, the majority of the cases in North America have been reported from the rural western United States. WEE is spread mainly by the vector mosquito C. tarsalis. Birds are the primary hosts for WEE because of their abil- ity to act as reservoirs to the virus and allow it to replicate easily (Leighton 2000). Birds are infected in the spring by virus-carrying mosquitoes; the virus replicates and ampliﬁes in the birds, other mosquitoes feed on the birds, the newly infected mosquitoes can infect more birds, and the cycle continues. WEE is common in the summer, with peaks in July and August when populations of the vector mosquito are the highest (Nadalur and Urban 2002). The risk of disease in humans and horses varies from year to year depending on the number of infected mosquitoes. A vaccine is available for horses, but there is no vaccine for general use in humans because of the small amount of veriﬁed WEE cases. Saint Louis Encephalitis The St. Louis Encephalitis (SLE) virus was ﬁrst recognized in 1933 in St. Louis, Missouri. Currently, the virus occurs throughout the United States, with higher concentrations in the Mid-West and Southern states with small (fewer than 30 people affected), isolated regional outbreaks (CDC 2001). Birds are immune hosts of the virus, which is transmitted between birds and from birds to humans and other animals by the blood- sucking mosquitoes (CDC 2001). The virus is transmitted and spread primarily by mosquitoes of the genus Culex. As with WEE, humans are a dead-end host for SLE. Most humans that are infected never show any symptoms of the disease. Currently, there is no vaccine against SLE. California Encephalitis The California Encephalitis (CE) virus was ﬁrst named after a human case diagnosed in 1946 in Kern Coun- ty, California (Soliman, No date). Since that time, most cases have been linked with the La Crosse virus. The La Crosse virus occurs in north-central states, primarily in the upper Mississippi River Valley, and is transmit- ted by the treehole mosquito, Aedes triseriatus. The vertebrate hosts of the virus are primarily small wood- land mammals, such as squirrels and chipmunks, which harbor the virus until it is passed to other mosqui- toes. The virus is able to survive the winter within the vector mosquito (CDC 2001). Only about 70 cases of La Crosse encephalitis are reported annually. West Nile Virus West Nile Virus (WNV) was ﬁrst found in the United States in 1999 in New York City and has since spread to 43 states (U.S. Geological Survey [USGS] 2002). The virus is carried long distances by infected birds and then spread locally by mosquitoes that bite the infected birds. The virus is primarily transmitted by mos- quitoes of the genus Culex. In Colorado, the mosquito species Culex tarsalis and Culex pipiens are known to be involved in the transmission cycle of the virus. C. tarsalis is considered more likely to transmit the virus to mammals, such as horses and humans, which are dead-end hosts. Humans and horses are de- scribed as dead-end hosts for the virus because, once it has been contracted, they cannot transmit the disease. The highest risk of WNV infection for humans is usually August through early September. Because the status of WNV in Colorado is changing rapidly, the most current information on WNV in the state can be found by referring to the WNV educational campaign web page at: http:// www.ﬁghtthebitecol- orado.com. For additional information on WNV, refer to the Centers for Disease Control and Prevention (CDC) web page at: www.cdc.gov/ncidod/dvbid/westnile/index.htm or by calling the Colorado Health Educa- tion 34 Line for the Public at 1-877-462-2911. The statewide, toll-free hotline, which is staffed by trained op- mosquito borne infectious diseases wnv mosquito management plan erators, is open from 7 a.m. to 11 p.m. seven days a week. Callers to the hotline will be able to obtain infor- mation in English and Spanish on a wide variety of topics relating to WNV, including the following: • Information on repellants and how they should be used both on adults and children. • Symptoms of WNV, however, hotline operators will not be able to help diagnose whether a person has contracted WNV. Rather such individuals will be referred to their personal physician for diagnosis and treatment. • Methods of preventing WNV. • How pets might be affected by WNV. West Nile Virus Pathway WNV is carried long distances by infected birds on seasonal migration patterns and then spread locally by mosquitoes that bite the infected birds. The virus is primarily transmitted by mosquitoes of the genus Culex. In the Boulder Area, the primary species of Culex are Culex tarsalis and Culex pipiens. These two species are considered the most likely to transmit the virus to mammals, such as horses and humans, which are dead- end hosts. Humans and horses are described as dead-end hosts for the virus because; once it has been contracted, they cannot transmit the disease due to inadequate amounts of viremia, or virus circulation in the bloodstream to infect other mammals or mosquitoes. Mosquito of the Culex genus overwinter and; therefore, can continue the disease the following spring. West Nile Virus in the U.S. WNV was ﬁrst isolated in 1937 and known to cause asymptomatic infection and fevers in humans in Africa, West Asia and the Middle East. First detected within the U.S. in the state of New York in 1999, WNV has spread from East to West across the United States by mosquito hosts and carrier birds. During 1999 and 2000, WNV encephalitis was found in U.S. residents in three northeastern states with a total of 83 human cases and 9 reported deaths. WNV spread westward in 2001 occurring in 10 states having 66 cases and 9 deaths. As of 2005 WNV has been detected in all states except for Alaska and Hawaii. There is currently no WNV vaccine for humans, but there is for horses. West Nile Virus in Colorado In 2002, Colorado had its ﬁrst cases of humans infected by WNV with 14 documented human cases and no reported WNV-related deaths (CDPHE 2004). These 14 cases occurred despite a severe drought. Addition- ally, 138 bird, 3 sentinel chicken ﬂocks, and 380 horses tested positive for WNV in 2002 (CDPHE 2004). During the 2003 mosquito season, Colorado lead the nation in WNV human cases (2,945) and WNV-related deaths (55) (CDPHE 2004). This is likely due primarily to Colorado’s wet spring and hot summer increasing mosquito breeding populations and earlier emergence as described earlier. The onset of human symptoms was ﬁrst documented with less than 10 cases on June 30, 2003, by CDPHE. The number of cases from June to September followed a Bell shaped curve with the major peak in August that year. West Nile Virus in Boulder County By the end of 2003 there were 430 WNV infections reported to Boulder County Public Health, 378 were diagnosed with WNV Fever and 52 with either WNV Encephalitis or Meningitis. Based on monitoring data among human cases from 2003, it is estimated that there were approximately 7,800 individuals infected with WNV in Boulder County (only 430 reported illnesses) (Harmon 2004). 35 mosquito habitat and biology wnv mosquito management plan APPENDIX E: GENERAL OVERVIEW OF MOSQUITO HABITAT AND BIOLOGY Larval Habitat Mosquitoes successfully inhabit almost every kind of collection of water. A “breeding site” can be any place that will hold water for a week or more after rainfall. Prime breeding sites include marsh edges, short-grass ditches, tire ruts, hoof prints, discarded tires left outdoors, poorly maintained bird baths, holes in trees, clogged rain gutters, unused swimming and plastic wading pools, and pots and pans with standing water, and many other habitats that will hold stagnant water (New York City Department of Health and Mental Hygiene 2003, Metropolitan Mosquito Control District [MMCD] 2002). The most proliﬁc breeding sites in the city are probably ﬂood-irrigated lands, and seasonally wet/dry locations when stagnant water is present. Some areas that do not support mosquitoes include moving water (rivers, streams, and creeks), deeper lakes, ornamental ponds, and duck ponds. Other conditions that are unfavorable for breeding of mosqui- toes are turbulence and the presence of natural predators. Adult Habitat In the daytime, adult mosquitoes avoid adverse environmental conditions, such as intense heat, by taking refuge in resting areas known as “harborage sites”. Typically, these resting areas are composed of natural vegetation, including forests, tree stands, grass, shrubs, or other foliage. Ideal resting areas are generally shaded with cooler daytime temperatures and high relative humidity. These conditions are typically found in forests or tree stands that have a canopy, and dense underbrush. Wetlands also may be present nearby. Other resting sites include culverts, hollow logs, areas underneath decks, shaded sides of buildings, base- ments, and garages. General Mosquito Biology Mosquitoes develop through four general stages in their life cycle. The following sections describe these four stages. Eggs – All mosquitoes must develop in water before they can ﬂy. The adult female mosquito, after taking a blood meal, will search for a place to lay her eggs. Culex mosquitoes lay eggs in clusters, also called egg rafts, on the water’s surface. C. tarsalis lay eggs in rafts on the surface of permanent and semi-permanent clear ground pools, springs, and ditches. In late summer, they also lay eggs in temporary pools and contain- ers that contain standing water. C. pipiens use standing or slow-moving water that contains decaying or- ganic materials to lay their eggs. Larvae – Larvae develop in shallow water. They have four growth stages known as instars (Figure D-1). They are found in the water hanging head down just below the surface because the larvae breathe through a respiratory siphon at the tail end of their body that breaks the surface of the water. When larvae ﬁrst hatch, they are less than _ inch long and they grow to be approximately _ inch long by the fourth instar. The larvae of C. tarsalis and C. pipiens are found in somewhat different habitats. C. tarsalis larvae are found in a wide variety of semi-permanent and permanent sources of water in both rural and urban areas (Nielsen et al. 2002). They occupy a wide variety of either fresh or polluted water habitats, usually in open, sunlit locations (Harmston and Lawson 1963). In contrast, C. pipiens larvae are found in a wide variety of natural and artiﬁcial sources of water that often are highly polluted with organic wastes (Nielson et al. 2002, Harmston and Lawson 1963). They have been found in containers of various types, catch basins, ornamental pools, cesspools, swimming pools that are not completely drained, ditches, and tree holes (Nielsen et al. 2002). Pupae – At the end of the fourth instar, the larva molts into a pupa. The pupa is a cocoon-like stage when the adult mosquito is forming. This stage typically lasts about 2 days; however, the amount of time spent in the pupa may vary depending on water’s temperature. The mosquito does not feed during the pupa stage, but when disturbed, will tumble as it avoids danger. Adult –When the adult is fully formed, it breaks through and emerges from the pupal skin. It rests for a short time on the water surface while its wings expand and dry. Male mosquitoes usually emerge ﬁrst and 36 form a swarm where they will mate with females as they emerge from their pupae. Females mate only once mosquito habitat and biology wnv mosquito management plan 37 and store sperm in their bodies to fertilize their eggs as they are laid. Once the female has mated, she ﬂies off in search of a blood meal to obtain the proteins necessary for laying eggs. Males and females feed on plant nectar for energy. A number of factors inﬂuence the blood feeding of the adult female. They include humidity, wind, tem- perature, light, and animal emanations (such as respiration or body heat). For most mosquitoes, the pri- mary period for feeding on blood is between sunset and midnight during the summer. A second feeding period occurs around sunrise. This feeding behavior may change during the spring and fall, when daytime conditions favor mosquito activity over evening conditions. Temperatures above 55 degrees F and humidity levels at or in excess of 70 percent are optimum feeding conditions. Mosquitoes of the genus Culex can overwinter as gravid (egg bearing) females. This characteristic results in populations that are low in numbers in the spring but grow geometrically during August and September. Because the populations of mosquitoes increase greatly late in the summer, potential vectors and disease transmission are most prevalent at this time. C. tarsalis breeds several generations per year. Females overwinter in protected places, including caves, abandoned mines, and cellars (Harmston and Lawson 1963). Adults prefer to feed on birds, but will bite humans and other mammals (Nielson et al. 2002; Harmston and Lawson 1963). Feeding occurs near dusk and after dark (Nielsen et al. 2002). Its life cycle varies from 4 days to 30 days, depending on conditions. C. tarsalis commonly travels up to 2 miles for a blood meal. Collections have been made at elevations up to 10,000 feet (Harmston and Lawson 1963). C. pipiens females hibernate in cellars, basements, and other protected sites (Harmston and Lawson 1963). Studies suggest that birds are the major hosts of C. pipiens because it takes blood meals from them more than 95 percent of the time. Mammals constitute the rest, with humans representing less than 1 percent of the total (Nielsen et al. 2002). C. tarsalis is probably the main carrier of WNV because of its afﬁnity to take blood meals from birds. At least 120 bird species and eight mammal species have been infected (USGS 2002). Corvids (crows, magpies, ra- vens, and jays) seem to be affected more than other species; however, because many corvids die when in- fected, they are not an ideal host for the virus. Other species, such as house sparrows, do not seem to die as readily when infected and are therefore a more effective host for the virus. wnv task force Figure D-1 Mosquito Life Cycle wnv mosquito management plan 38 APPENDIX F: CITY-WIDE STAFF WEST NILE VIRUS TASK FORCE The city has set up “teams” of staff to help in the decision-making and implementation of the West Nile Virus Mosquito Management Plan. Technical Team The technical team is a group of city staff members who have knowledge and expertise in pest control and, as best known to date, West Nile Virus. This group consists of: • Team Lead, WNV Project Co-Manager, Ofﬁce of Environmental Affairs (OEA) • OEA intern • Open Space and Mountain Parks • Parks and Recreation • Transportation & Utilities Maintenance • Monitoring and Control Consultant Public Affairs Team The public affairs team is a group of public information specialists from throughout the city that are led by Public Affair’s staff. The group is tasked with developing and implementing the city’s communication plan on WNV to both internal and external customers of the city. • Team Lead - WNV Project Co-Manager, Public Affairs • Public Affairs • City Manager’s Ofﬁce • OEA • PIT (as needed) - Public Information Team (public information representatives from departments city-wide) City-wide Staff Task Force The city-wide task force is made up of representatives of the departments and ofﬁces within the city. The task force shares information, asks questions of the technical and public affairs teams, coordinates individual department efforts with other departments, and brainstorms ways to engage city staff and the public in the prevention of WNV. Task Force Co-Leaders: wnv task force • WNV Project Co-Manager, Public Affairs • WNV Project Co-Manager, OEA Participating Departments • City Manager’s Ofﬁce • Environmental Affairs • Fire Department • Housing and Human Services/Senior Services • Human Resources • Library • Municipal Court • Open Space and Mountain Parks: • Parks and Recreation • Public Affairs • Public Works 2006 wnv mosquito management plan 39 2006 WNV Mosquito Management Plan Prepared by: City of Boulder Ofﬁce of Environmental Affairs In collaboration with OtterTail Environmental Inc. 1 1 West Nile Virus Management Policy and Response Plan Season Summary October 29, 2013 2 Overview • Council Feedback • Program Purpose and Focus • Background • Summer of 2013 – What Went Well? – Areas for Improvement. • Annual Review Process ATTACHMENT 6 2 3 Direction Sought • What is working well with the existing WNV Policy and Program Response Guidelines and what areas need to be improved? • Does Council concur with the proposed review process? Are there any adjustments Council would like to see? 4 Program Purpose • Reduce the risk of human West Nile Virus infection while limiting adverse human health and environmental impacts. 3 5 Program Focus • Provide a wide range of public outreach and education • Extensive on-going mosquito populations data collection and monitoring, including WNV testing • Aggressive larval control program focusing on Culex mosquitoes • Periodic review to ensure program efficacy 6 Background • West Nile Virus present in Colorado in 2002 • City Response: broad based, prevention focused management plan • Emergency adulticide: 2003, 2004, 2007 – 2007: Technical Advisory Committee formed • 2008 West Nile Virus Management Policy adopted 4 7 Background • West Nile Virus Management Policy – Public awareness – Larval mosquito monitoring and control – Adult mosquito trapping and testing – Adulticiding decision process • Aug. 2012 adult mosquito operation initiated per Program Response Guidelines • Nov. 2012 - Mar. 2013 Technical Advisory Committee review operation, develop recommendations 8 Background • March, 2013 Council Review of TAC recommendations: – Re-establish Backyard Inspection Program. – Re-establish Stormwater Drain Program. – Enhance communication with Poudre School District and Colorado State University. – Increase Vector Index from 0.5 to 0.75. – Enhance gravid trap network. • Aug. 2013 adult mosquito operation initiated per Program Response Guidelines 5 9 2013 Season Summary • 91 cases of WNV in the County. • 60 cases in Fort Collins. – 51 WNV Fever cases. – 9 neuroinvasive cases. – 3 blood donors. • 49 cases contracted pre spray. • 11 cases contracted the week of spraying or later. 10 What Went Well • Application completed on schedule in four evenings avoiding New West Fest weekend. • Successfully avoided properties listed in Pesticide Sensitive Registry • Post-application trapping showed a reduction of the Vector Index from 0.85 to 0.25. • Effective use of social media, website and electronic communication tools • Print and phone notices provided in English and Spanish 6 11 Communication Highlights Prevention & Awareness: • 47,000 utility bill inserts sent in July • 30-second “Fight the Bite” PSA on Cable 14 • News releases • Web updates; Facebook, Nexdoor.com & Twitter posts • 22,000 door hangers in high risk areas Adulticiding Notices: • Email notifications to 3640 subscribers • Social media posts (Facebook reached 23,712 followers) • Non-emergency phone notifications to 30,468 landlines (approx. 64% successful connections) • News releases 12 Areas For Improvement • Improve the public outreach process concerning the adulticiding application – Re-evaluate use of phone system – Adequate testing time and web infrastructure to better utilize GPS tracking system – Increased effort to promote email subscription service • Enhance WNV education and community engagement process 7 13 Review Process • Reconvene the Technical Advisory Committee to review the adulticide operation of 2013. • Investigate Best Management Practices of other agencies: – City of Boulder – Fort Worth, Texas • Recommendations to Council in spring of 2014. 14 Direction Sought • What is working well with the existing WNV Policy and Program Response Guidelines and what areas need to be improved? • Does Council concur with the proposed review process? Are there any adjustments Council would like to see? Successful? YES NO Return to Top ADULT MOSQUITO CONTROL FLOWCHART DAY 1 DAY 2 West Nile Virus present (from Adult Surveillance Flowchart) OtterTail and City Officials make determination to perform adult control Contact adult control company immediately (to allow 48 hours to mobilize) Perform control (1/2 to 1 square mile in area) Perform post control collections (set traps, perform sweeps) Enter information into database Contact law enforcement if necessary to provide police escort for fogger trucks (48 hours prior) Determine where the adult control efforts should be focused (then set traps and perform sweeps) 48 hours prior to control: • Distribute informational adult control brochure in _ to 1 mile radius of epicenter • Issue press release • Post all areas where control will take place DAY 1 & DAY 2 Figure 3-4 Adult Mosquito Control Flowchart chapter three nities (179 genera of aquatic insects from 7 orders) in 27 wetlands Delayed toxicity to many dipteran genera, mostly chironomids, and some non-dipteran predator genera Total insect density signiﬁcantly reduced by 60 percent in second and third year of normal treatment. Total dipteran density signiﬁcantly reduced by 62 percent and 82 percent in second and third year of normal treatment. Total insect richness (number of genera) signiﬁcantly reduced by 33 percent to 67 percent in second and third year of normal treatment. Chironomid richness reduced by 43 percent and 66 percent in second and third year of normal treatment. Non-dipteran predator genera richness reduced by 64 percent in third year of normal treatment. Results indicate a profound change in wetland function and indirect adverse effects are likely for vertebrate predators of chironomids (such as waterfowl). LITERATURE REVIEW OF TOXIC EFFECTS FROM BACILLUS THURINGIENSIS SUBSPECIES ISRAELENSIS ON NON-TARGET ORGANISMS Note: 1 LC50 = Lethal concentration to 50 percent of test population. Sources: EPA 1998, Joung and Côté 2000, Merritt and Wipﬂi 1994, Garcia et al. 1980, Agriculture Canada 1982, and Hershey et al. 1998. Table 2-1 Literature Review of Toxic Effects from Bti on Non-Target Organisms APPENDICES Appendix A: City of Boulder IPM Policy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Appendix B: Pesticide Labels and MSDS Sheets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Appendix C: Contracts and Permits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Appendix D: Mosquito-borne Diseases That May Occur in Colorado. . . . . . . . . . . . . . . . . . . . 34 Appendix E: General Overview of Mosquito Habitat and Biology . . . . . . . . . . . . . . . . . . . . . . 36 Appendix F: City-wide WNV Task Force . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Appendix G: Communication Plan Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . XX