Update on Duet™ and insecticide-treated surfaces

Sandra A. Allan

Center for Medical, Agricultural and Veterinary EntomologyARS/ USDAGainesville FL

DoD Pest Management WorkshopJacksonville NASFebruary 12 2010

Update

1. Effect of ULV droplets of DUET™ on mosquito (Culex quinquefasciatus) responses

2. Behavioral effects of ULV droplets of DUET™ on the sand fly (Lutzomyia shannoni)

3. Effect of different insecticides on surfaces onlanding by mosquitoes and sand flies

Hypothesis

Prallethrin contained in Duet enhances flight activity and results in greater mortality

Objective

Quantify mosquito excitation and mortality caused by Duet and its components applied as an ultra-low-volume aerosol

Military Relevance

Duet may be a ULV formulation useful for military applications

Duet™

New product

1. Effect of ULV droplets of DUET™ on Culex quinquefasciatus responses

Treatments

Components A B C D E

Prallethrin - 1% 1% 1% -

Sumithrin 5% - - 5% -

Piperonyl butoxide 5% - 5% 5% -

Inert Ingredients + + + + +

Formulations obtained from Clarke Mosquito Control

Sprays delivered at a sublethal rate so that behavior can be observedsublethal

Side view of wind tunnel

air flowFan Fan

IntakeOutput

Pesticide filters

FiltersLam

iniz

erR

educ

er

Door

Pesticide cloud delivery

Door Lam

iniz

er

*

screened cagewith mosquito

Filters

4 fto

Video recording

Individual mosquitoes placed in screened cage in wind tunnel downwind of spray inlet

*

pre-spray post-sprayspray

5 min 5 min2.5 min

Video recordings were 12.5 min long:

Video Analysis using behavioral analysis software (Observer)

Behaviors of individual insects are coded with start and stop times by different keys and data exported to Excel for analysis

Event panel

Assay cage in wind tunnel

Event time Behavior

Video Analysis using motion analysis software (Motus)

Manual tracking of individual insect produces a flight track and x-and y-coordinates that are exported to Excel for further analysis

Assay cage in wind tunnel

Cursor on top of insect

Resulting flight track

ULV Droplet analysis

Mosquitoes treated in the wind tunnel were dissected and body parts placed on slides

Droplets were measured and counted

50 microns

Conclusions

Behavior: (pre-spray compared with spray and post-spray) Prallethrin produced increased flight activity (excitation)

during spray Sumithrin produced increased flight activity post-spray Controls: no differences in behavior were observed

Mortality:

Increased mortality appears to be linked to increased activity levels during spray, especially when exposed to treatments with prallethrin

0

10

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0% 25% 50% 75%

No.

of D

ropl

ets

Per

Mos

quit

o

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0% 25% 50% 75%Dro

plet

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ume

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3 ) P

er M

osqu

ito

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Volume 1000 μm3 = 1-6 μL

PRE-SPRAY SPRAY POST-SPRAY

% Time Flying % Time Flying% Time Flying

r=0.536P<0.0001

Increased flight results in increased droplet contact

Droplets

Pre-spray Spray Post-spray

Objective

Quantify sand fly excitation and mortality caused by Duet™ and its components applied as an ULV spray

MethodsSimilar to study with mosquitoes except: Used field-collected Lutzomyia shannoni Smaller assay cages Double screening to contain sand flies

2. Behavioral effects of ULV droplets of DUET™ on the sand fly (Lutzomyia shannoni)

0

20

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100

Legs Wings Body

% o

f to

tal

dro

ple

ts

Sand fliesMosquitoes

Detection of ULV droplets of Duet on body parts

Droplets most detected on wings of sand flies

Sand fly wing

50 microns

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35

2.5 5 7.5 10 12.5 15

Droplet size (um)

Mea

n n

o./

ind

ivid

ual Sand flies

Mosquitoes

Droplet size distribution – Comparison between sand flies and mosquitoes

More small droplets detected on sand flies than on mosquitoes

Sand fly wing

10 microns

Mortality of sand flies after treatment with Duet formulations in wind tunnel

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60

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100

A B C D=Duet E

% m

ort

alit

y

1 hr

24 hr

Treatmentscontaining prallethrin

Treatments containing prallethrin had higher mortality at 24 hr

Sand Fly Duet - MidA7

Sand Fly Duet - Mid B7

Sand Fly Duet - Mid C1

Sand Fly Duet - Mid D4

Sand Fly Duet - Mid E25

Sumithrin, PBO + inerts

Prallethrin, PBO + inerts

Prallethrin + inerts

Duet (sumithrin, prallethrin, PBO + inerts)

Control (inerts)

Flight tracks of sand flies (Lutzomyia shannoni) exposed to ULV spray of Duet in wind tunnel

During spray

More movement by sand flies exposed to prallethrin

Conclusions

Similar to mosquitoes, sand fly activity and mortality is enhanced in the presence of prallethrin

If given a choice, will mosquitoes land on surfaces treated with residual pesticides?

Are there differences between mosquitoes and sand flies?

Objective To compare landing of mosquitoes and sand flies on surfaces treated with different residual pesticides

Military RelevanceTo identify the most effective available residual pesticides for control of mosquitoes and sand flies

3. Effect of different insecticides on surfaces on landing by mosquitoes and sand flies

Active ingredient Formulation AI (%)

Bifenthrin Talstar One 7.9Cyfluthrin Tempo Ultra (SC) 11.8Deltamethrin Suspend SC 4.75Permethrin Dragnet 36.8Lambda-cyhalothrin Triazicide 0.002%

Methods

Selected residual insecticides approved for application on vegetation and other surfaces for mosquito control

Applied to surfaces at maximum label rate

Methods

Species Aedes albopictus (lab-reared)Lutzomyia shannoni (field-collected)Phlebotomus papatasi (lab-reared)

Approach Each test cage with:

Filter paper

Wax myrtle leaves

Treated surface Control surface

Methods – Mosquito videotaping

Assay cage

Camera

Methods – Sand fly videotaping

Assay cage

Camera

Preliminary Conclusions

Mosquitoes were more sensitive than sand flies to pesticide-treated substrates

Repellent responses were stronger to treated filter paper than to treated leaves which likely reflects a higher dose on the filter paper

Landing responses were least affected by lambdacyhalothrin and most decreased by permethrin

Acknowledgements

CMAVE

Gary Clark Miriam Cooperband (USDA/APHIS)Erin VrzalFran Ellison William Jany, Clarke Mosquito ControlLarry PittsEric PaulsenLee Cohnstaedt

This study was supported in part by funds from the Deployed War-Fighter Protection Research Program from the U.S. Department of Defense through the Armed Forces Pest Management Board to the Agricultural Research Service of the U.S. Department of Agriculture.