Impact of Selected Insecticides Used in Eggplant Production on Edovum puttleri Grissell (Hymenoptera: Eulophidae)

Abstract

The impact of insecticides currently used in commercial eggplant fields to control the Colorado potato beetle, Leptinotarsa decemlineata (Say), on the egg parasitoid Edovum puttleri Grissell was evaluated. Mortality from contact exposure to leaf residues and ingestion of contaminated honey, and parasitoid emergence from treated egg masses were compared for the following insecticides: esfenvalerate alone and in combination with piperonyl butoxide (PBO), oxamyl, PBO, and rotenone alone and in combination with PBO. Studies were conducted using concentrations of 1.0X, 0.75X, 0.5X, and 0.25X of the maximum labeled rate. Mortality was high and significantly different from controls for all chemicals and rates in both the leaf residue tests and feeding studies. Emergence of E. puttleri from treated egg masses also was significantly impacted by all materials and rates with the exception of PBO. The data suggest that the use of these materials in a pest management program that utilizes E. puttleri may reduce the survival of adults and emergence from eggs, thereby slowing parasitoid establishment.