Aerial Applications of Altosid 5% for the Area-Wide Control of Aedes aegypti and albopictus Populations Christopher R. Lesser/Mark D. Latham Manatee County Mosquito Control District
Domestic Mosquitoes Aedes aegypti Aedes albopictus Culex quinquefasciatus Culex nigripalpus
Rules to Remember for Controlling Mosquitoes Adulticides: Must present small droplets to actively flying mosquitoes typically at evening or night Larvicides: Must introduce the chemical to the water Social Concerns: Must be able to introduce intervention w/o creating havoc with the public Cost Limited Funds
Compare/Contrast: Traditional vs. Domestic Mosquitoes Traditional Ae. taeniorhynchus, vexans, Ps., Cx. Salt marshes, pastures, roadside ditches, rural Species Source Domestics Aegypti, albopictus Small and isolated containers, tree holes, urban Night/evening Activity Period Daytime Concentrated and focused; predictable pop. spikes Population Dynamics Widespread and diffuse; continual emergence Moderate to High Chemical Susceptibility Low to Moderate (resistance to many OP/SP adulticides)
If you can eliminate those used tires, buckets, trash, and 15-year old boat from your backyard then your mosquitoes will be eliminated
I already pay $40/year in taxes for mosquito control Isn t that what you get paid to do?
There is no Santa Claus.. but in an Ideal World Best form of domestic mosquito control is sanitation and source reduction but. Public won t do it Forced sanitation is difficult and unpopular (illegal) And access by us is often difficult/impossible (dogs, guns, knives, fences, labor, time) Scope: Each domestic inspection 20min/home x 6hr field day = 18homes per day = 6 acres/day (for 2 inspectors)!!!!
Domestic Complaints received by Manatee County MCD June, July, August 2011
25,000 acre treatment area Need 4,200 days for 2 people to make a complete sanitation operation (11.5 yrs) Or need 140 employees to make the complete inspection every 30-days Cost - $7.0 million in direct/indirect employee costs
Why Do We Control Mosquitoes Nuisance Control/Quality of Life Economic Importance Disease Suppression/Public Health Dengue Yellow Fever
2011 (July) (1) DENV-? Martin 2011 (Sept) (1) DENV -1 Hillsborough DENV-1 2009: 27 cases 2010: 68 cases 2011: 0 cases 2011 (Sept) (2) DENV-1 Palm Beach 2010 (2) DENV -3 Broward 2011 (Jan. Aug. Sept.) (3) 2010 DENV -1 DENV -2 Miami - Dade Miami - Dade
From Florida Keys Mosquito Control District
Dengue Key West vs. Singapore No. of Dengue Cases 10000 9000 8000 7000 6000 5000 4000 3000 2000 1000 0 Key West Singapore 65 Key West Cases 2007 2008 2009 2010
Incidence of Dengue: Key West vs. Singapore 350 Dengue Cases per 100,000 300 250 200 150 100 50 0 Key West Singapore 2007 2008 2009 2010
Successes and Not-So-Successful Worldwide, there has been some success in controlling aegypti but mainly in those countries where military rule is employed.. via Dr. Fred Soper (Thailand, Vietnam, Brazil, Cuba) The US has very poor success in numerous cases (none successful) Miami-Dade 10 yr pgm employing door-to-door sanitation.. mid 1980 s to present Code Enforcement
Domestic Inspections in Miami-Dade Conducted November thru May 8 teams of 2 inspectors, each team assigned a section (square mile) at a time All accessible premises inspected Containers emptied, yards sprayed when necessary, educational flyers distributed to every premise 65,000 premises inspected annually Whole county inspected every 5-7 years No significant change between 1995 2001
Other US Attempts: Florida Keys - Response to Dengue: 27 Human cases in 2009; 67 cases in 2010, 5% infected Added 8-10 new inspectors covering an area 2x4 mile (5,000 acres), aerial larviciding, ground adulticiding, source reduction, public education, TV and radio, lethal ovitraps.. 2 years later 15% reduction
Purpose & Objective Continue a 5-year research program to develop an effective IPM strategy for areawide control of Ae aegypti and albopictus Previous Research evaluated multiple control strategies and found: Truck applied ULV larvicides and adulticides can be effective in some locations/habitats when sprayed in combination.. but expensive and time consuming Truck applied ULV larvicides (alone) and truck applied ULV adulticides (alone) have no effects upon reducing domestic mosquito populations
Study Location
Study Location
Germination Paper
Eggs on Paper
Larvicide Adulticide Larvicide + Adulticide Control Efficacy of 3 Techniques For Ae. aegypti/albopictus Control (Values Indicate Average # of Eggs & Larvae at 15 Sampling Sites within each group) Weekly adulticiding & larviciding activities started on 7/21. 239.3 183.1 168.6 158.4 166.1 153.8 142.7 143.3 147.2 158.9 135.9 131.3 126.4 127.9 132.1 115.5 105.5 90.7 105.0 87.2 97.7 81.1 77.3 102.5 82.2 82.5 97.5 77.9 85.3 70.1 69.1 79.6 74.1 61.7 57.5 51.3 52.1 51.5 53.1 40.7 45.7 46.7 46.4 46.4 30.6 42.1 43.3 33.8 32.6 34.7 25.4 20.1 24.0 31.4 21.1 34.5 Larviciding Stopped 3.9 7.7 7.7 3.2 6.3 0 6/29 7/7 7/13 7/20 7/28 8/3 8/11 8/17 8/24 9/1 9/8 9/14 9/21 9/28 10/5 10/12 Date of Collection 210.1 240.0 300 250 200 150 100 50 0
Percent Population Change Efficacy of 3 Techniques for Ae. aegypti and Ae. albopictus Control; Data Normalized by Location and Corrected for Control Variation 400 350 377.06 Larvicide Adulticide 300 250 262.00 Larvicide and Adulticide Control 200 150 167.51 207.51 159.99 135.74 100 73.23 81.17 70.50 72.64 72.32 62.42 50 18.02 7.78 30.32 34.62 2.05 0 0.00-25.83-50 -25.16-8.17-27.12-42.06-46.03-70.44-56.51-61.94-76.70-78.30-80.08-84.12-72.94-100 7/20 7/28 8/3 8/11 8/17 8/24 9/1 9/8 9/14 9/21 9/28 10/5 10/12 Date of Ovitrap Collection
Would Aerial Applications Be More Effective?
Methodologies 2011 Two study sites selected (128 and 413 acres); both within older residential neighborhoods in/near Bradenton, FL with history of high domestic mosquito problems Spray Platform: Hughes 500D; spray block treated 1x per fortnight starting in mid August for a total of 3 applications Larvicide = Altosid 5% (diluted to 1% tank mix) delivered through spray system at 240psi yielding a VMD of ca. 250-400microns at final application rate of 19.5 fl oz/ac in a 200ft swath (equivalent to 4.0 oz/ac Altosid 5%)
Methodologies (cont.) Measured mosquito population dynamics via 15 ovitraps located within each of the study sites; eggs and larvae were collected and counted weekly Selective hatching of collected ovi-strips (paper) found 95% Aedes aegypti and 5% albopictus in each of the study sites Larvicide applications made late in the evening/early morning when human outdoor activity would be predictably low. Generally between midnight and 2am.
Efficacy of Aerial Larviciding upon Ae. aegypti/albopictus Populations (Values Indicate Average # of Eggs & Larvae at 15 Sampling Sites within each group) 161.5 167.2 Aerial Larvicide - Methoprene on 8/16, 8/31 and 9/14; Midnight - 2am 128-acres Control Treatment 130.8 180 160 140 107.1 110.1 104.3 99.4 94.7 88.7 91.2 78.2 69.7 66.9 62.2 63.6 70.2 57.0 60.5 62.3 59.8 53.8 53.5 55.7 51.6 52.1 48.2 40.7 32.8 31.1 30.5 27.2 24.1 64.6 60.0 64.1 60.6 52.1 51.9 34.9 29.9 25.2 26.1 23.1 31.4 18.1 23.3 9.6 5/2 5/9 5/16 5/23 5/31 6/6 6/13 6/20 6/27 7/5 7/11 7/18 7/25 8/1 8/8 8/15 8/22 8/29 9/6 9/12 9/19 9/26 10/3 10/10 Date of Collection 120 100 80 60 40 20 0 Number of Eggs and Larvae
Results The practices of aerial larviciding appears to have a significant effect upon reducing Ae. aegypti and albopictus populations. About 75% in this study Delivery Systems: Aerial applications are a much more effective chemical delivery method as compared to ground-ulv larvicide applications probably as a result of a more uniform chemical application. (2010 and 2011 data showed Ground Larviciding had no population reducing effects on local domestic mosquitoes)
Discussion Aerial ULV adulticiding would likely not be an effective control agent for domestic mosquitoes for a number of different reasons (mosquito behavior, meteorology and spray cloud dynamics, public acceptance, etc) Aerial ULV applications appear to be very effective Ground ULV applications likely not applicable to area-wide applications given time constraints and costs This study was conduct under the purview of an EUP from FDACS
QUESTIONS? Christopher.Lesser@manateemosquito.com