Azadirachtin effects on mating success, gametic abnormalities and progeny survival in Drosophila melanogaster (Diptera). Issue 1 (12th September 2017)

• Record Type: Journal Article
• Authors: Oulhaci, Chemseddine M; Denis, Béatrice; Kilani‐Morakchi, Samira; Sandoz, Jean‐Christophe; Kaiser, Laure; Joly, Dominique; Aribi, Nadia
• Is Part Of: Pest management science. Volume 74:Issue 1(2018)
• Page Start: 174
• Page End: 180
• Publication Date: 2017-09-12
• Subjects: natural pesticide -- azadirachtin -- toxicity -- spermatogenesis -- oogenesis -- Drosophila; Pests -- Control -- Periodicals; Pesticides -- Periodicals; 632.9
• DOI: 10.1002/ps.4678
• Languages: English
• ISSNs: 1526-498X

Abstract

Abstract : Azadirachtin induced a drastic decline of reproduction success via a reduction of mating, number of cysts and oocytes with a decrease of basal oocyte size and cysts abnormalities. Abstract: BACKGROUND: Azadirachtin is a prominent natural pesticide and represents an alternative to conventional insecticides. It has been successfully used against insect pests. However, its effects on reproduction require further analysis. Here we investigated lethal and sublethal effects of azadirachtin, on treated adults in a model insect, Drosophila melanogaster (Meigen). Dose–mortality relationships as well as several parameters of reproduction (mating, spermatogenesis, oogenesis and fertility) were examined. RESULTS: Neem‐Azal, a commercial formulation of azadirachtin, applied topically on newly emerged adults, increased mortality with a positive dose‐dependent relationship. The LD50 (0.63 μg) was determined 24 h after treatment using a non‐linear regression. Adults surviving this dose had a mating success that was divided by 3 and a progeny production reduced by half when males were treated, and even more when females were treated. When combining probability of survival, of mating and reduced progeny, it appeared that LD50 induced a 98% reduction in reproductive rates. Reduced progeny was partially explained by the effect of adult treatment on gametes number and abnormalities. The number of cysts and the apical nuclei positions within the cysts decreased by 29.7% and 20%, respectively, in males. In females, the number of oocytes per ovary and the volume of basal oocytes also decreased by 16.1% and 32.4%, respectively. CONCLUSION: Azadirachtin causes significant toxic effects in both sexes and decreases the fecundity and fertility of D. melanogaster . Females are more sensitive to azadirachtin. © 2017 Society of Chemical Industry