A Comparison of Predation by the Pentatomids, Podisus maculiventris (Say) and Stiretrus anchorago (F.)1, on the Mexican Bean Beetle, Epilachna varivestis Mulsant2, 3

Abstract

Predation by Podisus maculiventris (Say) and Stiretrus anchorago (F.) on the Mexican bean beetle, Epilachna varivestis (Mulsant), was studied in the laboratory and field cages. P. maculiventris accepted a wider range of E. varivestis stages as prey than did S. anchorago. Both predaceous pentatomid species responded to a rise in temperature with an increase in prey consumption. However, P. maculiventris responded more acutely to the increase in temperature than did S. anchorago. Prey consumption by each species increased at a negatively accelerating rate as prey density increased. These data were fitted to Holling's disc equation. S. anchorago had a distinct preference for E. varivestis to velvetbean caterpillar, Anticarsia gemmatalis Hiibner, while P. maculiventris took approximately equal numbers of each. Field cage data substantiated finding from laboratory studies in that E. varivestis larval populations were significantly reduced by both pentatomid species.