Impacto de insecticidas sobre tres parasitoides de Erinnyis ello (L.) gusano de cuerno de la yuca

The effect of the application of ethyl parathion, trichlorfon, diflubenzuron, and Bacillus thuringiensis var. kurstaki to eggs of Erinnyis ello, before and after being parasitized by Trichogramma exiguum and Telenomus sphingis, was studied. Insecticides were also tested on the adults of these parasites and on the adults and pupae of Apanteles congregatus. A methodology to rear A. congregatus was also developed. When ethyl parathion and trichlorfon were applied to eggs before being parasitized, they inhibited parasitism, restrained development of parasites within the eggs, and affected the longevity and productivity of female T. exiguum and T. sphingis from treated eggs. Diflubenzuron and B. thuringiensis did not affect these parameters. Ethyl parathion and trichlorfon, applied to parasitized eggs, inhibited the emergence of T. exiguum adults by 80 and 70 percent, and that of T. sphingis by 96 and 91 percent, resp. When females emerging from previously treated E. ello eggs were confined, diflubenzuron or trichlorfon affected longevity and parasitic activity in both species. Trichlorfon had a similar effect when applied to eggs parasitized by Trichogramma. B. thuringiensis had no negative effects. Diflubenzuron and B. thuringiensis did not affect the adults of the 3 parasite species nor the emergence of A. congregatus adults. In all expt., ethyl parathion and trichlorfon were the most toxic while overall, B. thuringiensis and diflubenzuron were the least toxic. (AS-CIAT)