Control of mosquito vectors of tropical infectious diseases: (2) pyrethroid susceptibility of Aedes aegypti ( l) collected from different sites in Thailand.
Four strains (SS, BS, A and B) of Aedes aegypti collected from different sites in Bangkok and at different times were examined for their pyrethroid susceptibility. Mosquito coils containing dl, d-T80-allethrin, d, d-T-prallethrin and methoxymethyl-tetrafluorobenzyl tetramethyl-cyclopropanecarboxylate (K-3050) with or without a synergist were tested by the 25 m3 semi-field test method. One strain (SS) was the most susceptible with KT50 values of about < 30 minutes for all mosquito coils, while the other three strains (BS, A and B) were found to be around 10 to 20 times more tolerant to pyrethroids than the SS strain. A similar tendency for the pyrethroid susceptibility of the four strains was obtained with tests by topical application method. In field efficacy tests, mosquito coils with d, d-T-prallethrin 0.20% plus N-(2-ethylhexyl)bicycle-[2,2,1]- hept-5- ene-2,3-dicarboxyimide as a synergist exhibited a repellent effect of about 85%, while those with K-3050 0.10% plus the synergist exhibited a greater repellent effect of about 90%. In contrast, the repellent effect of commercial dl, d-T80-allethrin 0.20% coils was as low as about 50%. The d, d-T-prallethrin and K-3050 coils with the synergist were confirmed to be highly effective in repelling Ae. aegypti.
Research and Development Laboratory, Dainihon Jochugiku, Osaka, Japan. y.minamite@kincho.co.jp
Yoshio
Y
Katsuda
Somjai
S
Leemingsawat
Supatra
S
Thongrungkiat
Samreng
S
Prummonkol
Yudthana
Y
Samung
Tsutomu
T
Kanzaki
Tomoe
T
Watanabe
Tomoko
T
Kahara
D000330:Aedes / Q000187:drug effects*; D000487:Allethrins / Q000494:pharmacology; D000818:Animals; D004351:Drug Resistance; D007302:Insect Repellents / Q000494:pharmacology*; D007303:Insect Vectors / Q000187:drug effects*; D010574:Pesticide Synergists / Q000494:pharmacology; D011722:Pyrethrins / Q000737:chemistry / Q000494:pharmacology*; D013785:Thailand
D000487:Allethrins; D007302:Insect Repellents; C533286:K-3050; D010574:Pesticide Synergists; D011722:Pyrethrins; C055818:d,d-T80-prallethrin