Effects of Temperature and Hunger on the Functional Response of Geocoris bullatus (Say) (Hemiptera: Lygaeidae) to Lygus spp. (Hemiptera: Miridae) Density 1

Abstract

Experiments were conducted to determine the effects of hunger on the functional response of female Geocoris bullatus (Say) to the combined density of two species of Lygus at three temperatures (15, 25, and 35°C). Models published by Holling and Rogers were fit to these data to predict values of handling times and searching rates. Observed handling times were much shorter than predicted handling times in all cases. Searching rates varied as the predator was starved. A simulation model incorporating handling time, searching rates, and hunger predicted acceptable rates of predation except when prey were very abundant. Under these conditions, observed rates were lower than predicted rates, probably because the predator spent most (71%) of its time in a small (32%) part of the arena.