Alightment of Edovum puttleri Grissell (Hymenoptera: Eulophidae) in Response to Colors Mimicking Three Hosts of the Colorado Potato Beetle (Coleoptera: Chrysomelidae)

The effect of leaf color on alighting behavior of Edovum puttleri Grissell was examined in a laboratory sticky-board test. Paint models mimicking the leaf top colors of eggplant, potato, and tomato and a model mimicking average underside leaf color were tested in paired comparisons. The underside leaf color mimic was the most preferred; no significant differences in landing rates occurred among any of the three leaf top color mimics. The underside leaf color mimic also was tested against two gray shades sharing the same intensity of reflectance; no significant differences were detected. The parasitoid, therefore, preferentially alighted based on the intensity and not the hue of the models. For all assays, a significant departure from randomness was found because a higher percentage of females alighted on the paint models than that which was in the colony. This suggests that parasitoids were alighting in a search for host eggs.

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

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.