Effects of Azadirachtin on the Biology ofLutzomyia longipalpis(Diptera: Psychodidae: Phlebotominae) Adult Female, the Main Vector of American Visceral Leishmaniasis

Abstract

The effects of azadirachtin A added to the sucrose diet of the adult females on the mortality, oviposition, and hatching of the sand fly vector of American visceral leishmaniasis Lutzomyia longipalpis (Lutz & Neiva, 1912) were investigated. Concentrations of 0.1, 1.0, and 10.0 microg/mg of azadirachtin significantly increased insect mortality in comparison with control insects. The same dose also significantly reduced oviposition but not hatching. After a long development period, significantly fewer adult insects were obtained from eggs hatching by azadirachtin-treated females in a dose-response manner. These results indicate that azadirachtin is a potent sterilizer that could be used against the development of Lu. longipalpis populations and as a tool for studying physiological and biochemical processes in phlebotomine species.

Azadirachtin effects on mating success, gametic abnormalities and progeny survival in Drosophila melanogaster (Diptera)

“…44 Indeed, a concentration of only 12 ppm causes 40% mortality in those species. Similar observations were reported by De Andrade-Coelho et al 46 in female adults of another Diptera, Lutzomyia longipalpis (Lutz and Neiva). Previously, azadirachtin was reported to impair, with variable effects, the survival of different insect species.…”

“…Indeed, a concentration of only 12 ppm causes 40% mortality in those species. Similar observations were reported by De Andrade‐Coelho et al . in female adults of another Diptera, Lutzomyia longipalpis (Lutz and Neiva).…”

“…Our study shows strong toxic effects of azadirachtin, from 24 h after topical treatment in D. melanogaster . We highlight a more drastic impact of azadirachtin on progeny output in treated females compared to males, even if this species is less sensitive than the targeted ones . The impact of azadirachtin on D. melanogaster may be explained by the widely documented inhibition of JH and ecdysteroids, and their interaction with insulin‐signalling pathways .…”

“…in female adults of another Diptera, Lutzomyia longipalpis (Lutz and Neiva). Previously, azadirachtin was reported to impair, with variable effects, the survival of different insect species . Strong variations in insects' susceptibility to azadirachtin were noted depending on insect order, species, formulation, or the method of application .…”

“…Previously, azadirachtin was reported to impair, with variable effects, the survival of different insect species . Strong variations in insects' susceptibility to azadirachtin were noted depending on insect order, species, formulation, or the method of application . Sensitivity of insects to insecticides varies also with the regulation of plasma membrane receptor and/or ion channels, penetration rate through the cuticle, absorption by insects, transport in tissues of the body and metabolism …”