Insecticide selectivity to ooencyrtus submetallicus (Hymenoptera: Encyrtidae) under extended laboratory conditions1

Abstract

Bioassays to evaluate the selectivity of pesticides to beneficial organisms are important tools to discriminate products compatible with biological pest control programs. This study aimed to evaluate the effects of the main insecticides used in the soybean crop on the egg parasitoid Ooencyrtus submetallicus (Hymenoptera: Encyrtidae). The tested treatments (active ingredients) were: methomyl, lambda-cyhalothrin + thiamethoxam, beta-cyfluthrin + imidacloprid, novaluron and teflubenzuron, in the highest doses indicated by the manufacturer for the soybean crop, and a control treatment (water). The evaluations enabled to calculate the mortality and parasitism capacity of adults exposed to the pesticides, in addition to the sex ratio of their descendants. Methomyl and lambda-cyhalothrin + thiamethoxam were classified as Class 4 (harmful), beta-cyfluthrin + imidacloprid as Class 3 (moderately harmful), and novaluron and teflubenzuron as Class 1 (harmless). The products classified as Class 3 and Class 4 should, as much as possible, be replaced by insecticides selective to O. submetallicus.