Lethal and Sublethal Toxicity of Insecticides to the Lacewing Ceraeochrysa Cubana.

Abstract

The lethal and sublethal effects of 11 insecticides on the predator Ceraeochrysa cubana (Hagen) were assessed under laboratory conditions. First-instar larvae and adults ≤ 48h old were sprayed with the highest insecticides doses allowed to control Diaphorina citri Kuwayama in the citrus crop. The survival and duration rates of the different development stages, sex ratio, pre-oviposition period, fecundity, and fertility of the insects were evaluated. In the larval bioassay, chlorpyrifos and malathion had lethal effect which none larvae survived. Azadirachtin, lambda-cyhalothrin + chlorantraniliprole, lambda-cyhalothrin + thiamethoxam, and thiamethoxam had lethal and sublethal effects that did not allow to estimate the life table parameters because the low number of couples formed. Esfenvalerate, imidacloprid WG and SC, phosmet, and pyriproxyfen had sublethal effects which were reflected in the net reproductive rate and in the intrinsic rate of natural increase. In bioassay using adults, none of the individuals survived in the chlorpyrifos, lambda-cyhalothrin + chlorantraniliprole, lambda-cyhalothrin + thiamethoxam, malathion, or thiamethoxam treatments, and the azadirachtin, esfenvalerate, imidacloprid WG and SC, phosmet, and pyriproxyfen treatments were significantly lower compared to the control. None of the insecticides was harmless to first-instar larvae and adults of C. cubana under laboratory conditions showing their potential to reduce the efficiency of this predator.