Effect of an oxadiazine, indoxacarb, on the biochemical composition of ovaries in the German cockroach.

Conventional insecticides have been widely used to control cockroaches but these insects have developed resistance to several compounds. Safer insecticides with a low toxicity such as oxadiazine have been advanced: indoxacarb (30% WG) is designated to be a reduced-risk insecticide and is considered as an organophosphate replacement. Insecticidal activity occurs via blockage of the sodium channels in the insect nervous system. In a first series of experiments, the toxicity of different concentrations (15, 20, 25 and 30 ppm) administrated by topical application to newly emerged adults was studied on the German cockroach Blattella germanica, and the LC50 and LT50 values were determined. In a second series of experiments, the compound was applied at its LC50 and LC90 over a period of 6 days, and the effects on the biochemical composition of ovaries (proteins, carbohydrates and lipids) during the adult life (2, 4 and 6 days) were examined.