Impact of insecticides on diamondback moth parasitoids on cabbage in the Federal District of Brazil

Abstract

The objective of this work was to identify parasitoids of Diamondback Moth in the Federal District. Larvae of the insect were collected in areas treated with insecticides or in untreated areas. Four species of parasitoids were identified: Apanteles sp. (Braconidae), Oomyzus sokolowiskii (Kurdjumov) (Eulophidae), Diadegma sp. (Ichneumonidae) and Actia sp. (Tachnidae). The total rate of parasitism ranged from 5% to 94% in fields untreated with insecticides, while they ranged between 11% to 87% in treated ones. Most Diamondback Moth larvae were found on cabbage head and on the underside of outer cabbage leaves. The larvae distribution could allow them to escape insecticide residues and so also allow parasitoid survival.