Activity of neem oil in Drosophila melanogaster: toxicity and delayed effect on the progeny

Abstract

Azadirachtin, derived from the neem tree, has been used successfully against insect pests; however, their effects on non-target organisms remain contradictory. The current study, examined the effect of neem oil, a commercial formulation of azadirachtin, on biological model of reference, D. melanogaster. In first bioassays, various doses of neem oil were tested, by topical application, on newly ecdysed pupae and the inhibition doses (ID) of adult emergence were determined (ID25: 0.68 μg; ID50 1.17 μg). Then, sublethal effects of neem oil have been specified on the weight of the pupae and on the fertility of adults that survived from treated pupae. Results showed that neem oil reduced, significantly, pupal weight at the two tested doses. Fertility and fecundity of various formed couples (between control and treated) were affected significantly by the insecticides excepted when only males were treated with the lowest dose. Thus, neem oil acts with delayed effects.