Evaluation of Spatial Repellents Under Semi-field and Field Conditions

Daniel L. KlineUSDA-ARS, CMAVE

Gainesville, FLdan.kline@ars.usda.gov

Spatial (area) repellents

Spatial (or area) repellent products are intended to significantly reduce the number of mosquitoes (and potentially other biting flies) in a defined area over a designated period of time.

Military Objectives

•Protect Individual SoldierSentry dutySpecial Operations•Protect Community of SoldiersTentWhole Encampment

Effects On Target Species

•Mortality•True Repellency•Expellency

Commercial Products Tested---2009

o Hot Shot No Pest Strip---2,2- dichlorovinyl dimethyl phosphate 18.6%o SC Johnson’s Clip-On---metofluthrin

31.2%o ThermaCell---d-cis/allethrin 21.97%

Semi-field Tests

4 ft 2 ft

2 ft 4 ft

4 ft8 ft

8 ftMortality Effects

Hot Shot with 2,2-diclorovinyl dimethyl phosphate 18.6% Aedes aegypti

Top position – 3(1’ from the ceiling)

Middle position – 2(3.3’ from the floor)

76-100%

51-75%

26-50%

0-25%

Mortality rate

S N

Bottom position – 1(1’ from the floor)

(Open end)

Hot Shot with 2,2-dichlorovinyl dimethyl phosphate 18.6% Aedes taeniorhynchus

Top position – 3(1’ from the ceiling)

Middle position – 2(3.3’ from the floor)

76-100%

51-75%

26-50%

0-25%

Mortality rate

NS

Bottom position – 1(1’ from the floor)

(Open end)

Hot Shot with 2,2-diclorovinyl dimethylphosphate 18.6% Stomoxys calcitrans

Top position – 3(1’ from the ceiling)

Middle position – 2(3.3’ from the floor)

76-100%

51-75%

26-50%

0-25%

Mortality rate

S N

Bottom position – 1(1’ from the floor)

(Open end)

Off Clip-On with metofluthrin 31.2%Aedes aegypti

Top position – 3(1’ from the ceiling)

Middle position – 2(3.3’ from the floor)

76-100%

51-75%

26-50%

0-25%

Mortality rate

S N

Bottom position – 1(1’ from the floor)

(Open end)

Off Clip-On with metofluthrin 31.2%Aedes taeniorhynchus

Top position – 3(1’ from the ceiling)

Middle position – 2(3.3’ from the floor)

76-100%

51-75%

26-50%

0-25%

Mortality rate

S N

Bottom position – 1(1’ from the floor)

(Open end)

Off Clip-On with metofluthrin 31.2%Stomoxys calcitrans

Top position – 3(1’ from the ceiling)

Middle position – 2(3.3’ from the floor)

76-100%

51-75%

26-50%

0-25%

Mortality rate

S N

Bottom position – 1(1’ from the floor)

(Open end)

ThermaCell with d-cis/allethrin 21.97%Ae. aegypti

Top position – 3(1’ from the ceiling)

Middle position – 2(3.3’ from the floor)

76-100%

51-75%

26-50%

0-25%

Mortality rate

S N

Bottom position – 1(1’ from the floor)

(Open end)

ThermaCell with d-cis/allethrin 21.97%Aedes taeniorhynchus

Top position – 3(1’ from the ceiling)

Middle position – 2(3.3’ from the floor)

76-100%

51-75%

26-50%

0-25%

Mortality rate

S N

Bottom position – 1(1’ from the floor)

(Open end)

ThermaCell with d-cis/allethrin 21.97%Stomoxys calcitrans

Top position – 3(1’ from the ceiling)

Middle position – 2(3.3’ from the floor)

76-100%

51-75%

26-50%

0-25%

Mortality rate

S N

Bottom position – 1(1’ from the floor)

(Open end)

Repellency Effects

Mosquitoes Released Into Each Cage

Ochlerotatus taeniorhynchus (500)Aedes aegypti (500)

Flies Released Into Each Cage

Stomoxys calcitrans (500)

Series10

10

20

30

40

50

60

70

80

90

100

23

0

20

0

55

0

16

40

0

28

18

35

Percent reduction in trap capture using Hot Shot No-Pest Strip, Summer 2009.

Ae. aegypti Ae. taeniorhynchus

Date

Perc

ent r

educ

tion

8/27 9/01 9/04 9/09 9/10 9/15

0102030405060708090

10089

8389 89 87 91

9889

95 9297

86

Percent reduction in trap capture using Off Clip-On repellent, Summer 2009.

Ae. aegypti Ae. taeniorhynchus

Date

Perc

ent r

educ

tion

6/30 7/02 7/07 7/09 7/21 7/23

Series10102030405060708090

100

75

87 82 8375

95

74 76 76

54

85

39

Percent reduction in trap capture using ThermaCell repellent, Summer 2009.

Ae. aegypti Ae. taeniorhynchus

Date

Perc

ent r

educ

tion

7/307/28 8/04 8/06 8/13 8/18

Arkansas Field Studies

Arkansas Field Studies

• 13 trap nights•Five species capturedPsorophora columbiaeAnopheles quadrimaculatusCulex erraticusCulex salinariusAedes vexans

Arkansas Field Studies

•None of the candidate spatial repellents prevented mosquitoes from finding the traps.

•Traps equipped with ThermaCELL captured significantly fewer mosquitoes.

What’s Next: Additional Compounds•Linalool•Geraniol•DEET•TL-I-73 transfluthrin analogue•1% prallethrin•1-Methylpiperazine•1-Ethylpiperazine•1-Methylpyrrolidine•Kamal’s compounds

What’s Next: Delivery Systems

• Attract and Kill Technologies• Spatial repellents and artificial barrier

treatments against Anopheles mosquitoes under field conditions

What’s Next:

Collaborators

•Ulrich Bernier• Jerome Hogsette•Kamal Chauhan• James Dunsford•Todd Walker•David Dame•Max Meisch

Acknowledgements

• Special thanks to Joyce Urban who did all the hard work• Jolene Malicoate for rearing Aedes aegypti•Haze Brown for rearing Aedes taeniorhynchus• Heather Furlong for rearing Stomoxys calcitrans