Cross-resistance to pyrethroid and organophosphorus insecticides induced by selection with temephos in Aedes aegypti (Diptera: Culicidae) from Cuba.
A sample of Aedes aegypti (L.) from Santiago de Cuba, Cuba, with a high level of temephos resistance (19.58x at the 50% lethal concentration [LC50]), was subjected to temephos selection to evaluate the utility of this organophosphate insecticide for mosquito control. High resistance developed after six generations of selection (200.00x). Little or no cross-resistance was observed to the organophosphates, malathion and fenitrothion, but high cross-resistance was observed for the pyrethroid deltamethrin (337.5x) and the organophosphate fenthion (12.74x). Synergism tests implicated detoxifying esterases in temephos and fenthion resistance and deltamethrin resistance was associated with a cytochrome P450 monooxygenasa. Biochemical tests, polyacrylamide gel electrophoresis (PAGE), and inhibition studies confirmed the presence of elevated esterase activity associated with temephos resistance. Pyrethroid resistance could be associated with a glutathione-S-transferase mechanism but not the esterases. The cross-resistance to deltamethrin from temephos selection could limit the use of both insecticides for Ae. aegypti control.
Rodríguez
María M
MM
Departamento de Control de Vectores, Instituto de Medicina Tropical "Pedro Kourí," Autopista Novia del Mediodfa Km 61/2, Entre Autopista Nacional y Carretera Central, A. Postal 601, Marianao 13, Ciudad Habana, Cuba. mrodriguez@ipk.sld.cu
Bisset
Juan
J
Ruiz
Michel
M
Soca
Alaín
A
D000330:Aedes / Q000145:classification / Q000187:drug effects*; D000818:Animals; D003462:Cuba; D004351:Drug Resistance / Q000502:physiology*; D004534:Egypt; D007306:Insecticides / Q000633:toxicity*; D011722:Pyrethrins / Q000633:toxicity*; D013045:Species Specificity; D000002:Temefos / Q000633:toxicity*
D007306:Insecticides; D011722:Pyrethrins; D000002:Temefos