Laboratory experiments were conducted to quantify the influence of weed plant species common to soybean fields in north Florida on rates of predation and oviposition byGeocoris punctipes(Say). Predation rates were affected by plant species and prey abundance when weed species were presented alone and when soybeans were presented with each weed in a paired free-choice arena. Rates of predation were comparatively low on weeds such as sicklepod, crotalaria, and Florida beggarweed. Interactions between soybeans and certain weed plants appeared to alter overall predation rates in free-choice arenas, resulting in reduced rates of attack on prey on soybeans. Changes in plant leaf area were shown to have a significant influence on the searching behavior of the predator. As plant leaf area increased, the predator responded by searching a bigger area, thereby maintaining a fairly constant rate of attack. Alterations in predator searching behavior as a result of plant species and species interactions were most important at the lower range of prey densities (prey per square centimeter leaf area) examined. Oviposition rates were influenced by plant species but not by prey abundance. Soybeans appeared to be a highly suitable plant oviposition site although oviposition on plants in general was very low