Heavy domestic andperidomestic infestations of

The effect of deltamethrin of the sandfly population in a focus of American Cutaneous Leishmaniasis in Viana, Espírito Santo State is described. The phlebotomine population density was determined inside and outside houses during a one year period in a treated and untreated area. The results showed a significant reduction in the number of sandflies inside houses in the treated area compared with both the untreated area and the same area before spraying. Despite having a residual action for 12 months after spraying the insecticide was ineffective outside houses. It is concluded therefore that deltamethrin is an efficient insecticide for reducing the number of phlebotomine sandflies inside houses.

This work demonstrates that deltamethrin in low doses produces an excito-repellency effect on triatomines, as already observed for mosquitoes. A wooden box covered with a cloth impregnated with deltamethrin at doses of 2.5 and 5mg ai/m 2 was utilized for the experiment. The triatomine species studied were Triatoma infestans, Panstrongylus megistus, Rhodnius neglectus and Triatoma sordida. Adults were released in one of the sides of the box and their position was noted in subsequent periods. The observations were realized on the day the cloth was impregnated and subsequently repeated at 30 and 60 days for T. sordida; on day 120, the remaining species were included. Insect mortality and attempts at flight from the box were also observed. Excitorepellency was evident for all species and doses up to day 120. The only species that attempted to fly was P. megistus. The excito-repellency effect may be considered as an additional advantage to the insecticide power, as it should be able to prevent the installation of new colonies by females that fly into the homes, and at the moment of the spraying, it should promote the flushing out of triatomines from the wall crevices and from other shelters. Key-words: Excito-repellency. Triatominae. Deltamethrine. Pyrethroid. Chagas' disease. Control.Resumo No presente trabalho procurou-se constatar se a deltametrina em baixas doses produz excito-repelência em triatomíneos, conforme já observado para mosquitos. O experimento foi realizado utilizando-se uma caixa de madeira recoberta com tecido impregnado com deltametrina nas doses de 2,5 e 5mg ia/m 2 . As espécies de triatomíneos estudadas foram o T. infestans, P. megistus, R. neglectus e T. sordida. Exemplares adultos eram liberados em um dos lados da caixa, e a posição dos mesmos era anotada em períodos subseqüentes. A experiência foi realizada no dia da impregnação do tecido, e repetida aos 30 e 60 dias para o T. sordida; aos 120 dias incluíram-se as demais espécies. Também foram observadas a mortalidade dos insetos e a tentativa de fuga da caixa através do vôo. A excito-repelência foi evidente para todas as espécies e doses até o 120 o dia. A única espécie que voou foi o P. megistus. O efeito excito-repelente pode ser considerado uma vantagem adicional ao poder do inseticida pois dificultaria a instalação de novas colônias a partir de fêmeas que ingressassem nas casas através do vôo, além de promover o desalojamento de exemplares presentes nas frestas das paredes e outros esconderijos. Palavras-chaves: Excito-repelência. Triatominae. Deltametrina. Piretróide. Doença de Chagas. Controle.

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Introduction:We attempted to supplement traditional insecticide spraying by treating peridomiciliar food sources with a powder formulation. Methods: Two groups of houses were treated with deltamethrin suspension concentrate (SC), one of which had its primary peridomestic food sources treated with deltamethrin 2P. Results: Triatoma brasiliensis was the most commonly captured triatomine. Birds, dogs and rodents were the major food sources identifi ed by the precipitin reaction; 554 domestic animals received powder treatment. A sharp reduction in infestation rates was observed in the two groups up to 360 days after spraying. Conclusion:The combination SC + 2P did not improve the control of triatomines.