Faucher-Delisle, J., Garcia, P.V., Nunes-Morgado, L. & Ventura, M.A. (2018) Sublethal effects of the ingestion of imidacloprid and deltamethrin by Chrysoperla agilis (Neuroptera: Chrysopidae). Açoreana, 11(2), 227-235.
The sublethal effects of two commonly used pesticides, Deltamethrin (Pyrethroid) and Imidacloprid (Chloronicotinyl) on the auxiliary insect Chrysoperla agilis (Neuroptera: Chrysopidae), were assessed. We followed the development and survival of immature stages fed on contaminated food, and evaluated the survival and sex-ratio of the emerged adults. For the ingestion essays, insecticides were sprayed on the larvae food (Ephestia kuehniella eggs) at doses recommended by the manufacturers for the control of aphids and whiteflies, using third instar larvae (L3) of C. agilis as predator. Deltamethrin treatment resulted in a high mortality rate amongst females, leading to a significant male biased sex-ratio when compared to Imidacloprid and control treatments, with 82.1% of male when adult stages were sexed. The weight gain of L3 was significantly lower after treatment with Deltamethrin compared both to control and Imidacloprid treatments. Contrarily, pupae weight gain was lower in Imidacloprid treated group, the only one differing significantly from the control. This shift in the weight gain (larvae vs. pupae) indicates a recovery trend in the Deltamethrin treated group that results in the absence of significant differences in the weight of the adults.