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

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 LD 50 (0.63 g) 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 LD 50 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.

Development Rate and Ultrastructure Changes of Puparia of Megaselia scalaris (Loew) (Diptera: Phoridae) Induced by Azadirachtin.

“…In addition, the percent pupation and the tendency of the treated pupae to develop to adults, obviously, decreased when they were treated as larvae with azadirachtin. The same findings were also reported for other insect species by using azadirachtin against Aphis glycines (Kraiss and Cullen 2008), Plodia interpunctella (Rharrabe et al 2008, Lynn et al 2012, Aedes aegypti (Koodalingam et al 2014), Drosophila melanogaster (Boulahbel et al 2015, Bezzar-Bendjazia et al 2016, Oulhaci et al 2018, Lutzomyia longipalpis (Andrade Coelho et al 2014) and Anopheles stephensi (Siddiqui et al 2003). The major retarding effect of azadirachtin on the development of M. scalaris, in the present study, can be explicated by the delaying effects of azadirachtin on the ecdysis and transformation of the insect.…”

Proteomic Profiling Analysis of Male Infertility inSpodoptera LituraLarvae Challenged with Azadirachtin and its Potential‐Regulated Pathways in the Following Stages

“…For insects, the reproductive ability was vital for species propagation and great potential as targets for insect control. Indeed, azadirachtin could have impacts on the reproductive ability of flies by regulating the yolk protein content in fat body and ovaries, postmating process of both sexes of flies, and the number of cysts and the apical nuclei position, reducing the size of the queens’ reproductive organs . However, the detailed mechanisms underlying such regulation were largely unknown.…”

Multi-tissue transcriptome analysis using hybrid-sequencing reveals potential genes and biological pathways associated with azadirachtin A biosynthesis in neem (azadirachta indica)

“…Azadirachtin A, the major insecticidal ingredient in neem-based products, exhibits excellent bioactivity against over 600 insect species [ 1 ] in agricultural areas [ 2 ]. It is processed by insects as a natural hormone and it induces antifeedant, repellent, and growth inhibiting behavior in insects [ 3 ]. Azadirachtin A-based pesticides are biodegradable, environment-friendly, and non-toxic to mammals, plants, and birds.…”