Effects of ingested indoxacarb (Oxadiazine) on biochemical composition of ovaries in Blattella germanica (Dictyoptera, Blattellidae)

Abstract

Cockroaches are generally controlled by conventional insecticides such as organochlorines, organophosphates and carbamates. However, these conventional neurotoxins possess strong secondary effects on the environment. In this context, the efficacy of a commercial formulation of indoxacarb (30% WG) was evaluated on Blattella germanica L. (Dictyoptera, Blattellidae), the most common species in Algeria. In a first series of experiment, the compound was applied by ingestion incorporated into the diet at different doses (0.125, 0.25, 0.50, 0.75, 1 and 2%) on adult females during a exposure period of 10 days under laboratory conditions. In a second series of experiment, the insecticide was tested by ingestion at the dose LD30= 0.127 %, on newly emerged adult females. Its effect was investigated on ovarian contents of proteins, carbohydrates and lipids. Results showed that treatment caused disoriented movements followed by tremors and paralysis. Moreover, biochemical analyzes revealed that the insecticide at the sublethal dose decreased the ovarian levels of proteins, carbohydrates and lipids. These biochemical modifications observed in B. germanica ovaries suggested an interference of indoxacarb with the reproductive process.