Evaluating Edovum puttleri Grissell and Podisus maculiventris (Say) for Augmentative Biological Control of Colorado Potato Beetle in Tomatoes

Abstract

Multiple releases of Edovum puttleri Grissell (Hymenoptera: Eulophidae) and Podisus maculiventris (Say) (Heteroptera: Pentatomidae) resulted in increased parasitism and predation rates of eggs of Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), in small plots of staked tomatoes grown in plastic or hairy vetch mulch. No consistent effect of the mulch on CPB infestations was found over the years of the study. No parasitism by E. puttleri occurred in 1995, while parasitism ranged from 0 to 30.6% per sample date in 1997. P. maculiventris nymphs were found at higher densities in release plots and readily attacked CPB egg masses. Despite the ability of both beneficials to search the structurally complex plant and find the pest, the cost of maintaining release rates that were high enough to achieve significant control of the pest would be prohibitive on a larger scale.