BODY WEIGHT OF PODISUS MACULIVENTRIS (SAY) UNDER VARIOUS FEEDING REGIMENS

Abstract

AbstractBody weights were measured for Podisus maculiventris (Say) (Heteroptera: Pentatomidae) given low prey inputs. Predators were fed green bean slices ad lib and a single mealworm larva (Tenebrio molitor L.) of one of two size classes, for a 24-h period every 1, 2, 4, 8, or 16 days. Other treatments included predators fed to excess of daily attacks, predators given only green bean slices, and predators given no food. Results showed that predators fed bean slices maintained body weight after an initial decline, whereas predators given no food lost weight continually until death. Predators maintained weight when fed prey ad lib, and when fed prey of either size daily. Those fed at longer intervals lost weight between feedings, and weight fluctuations increased as the interfeeding interval increased. Slopes of weight change between feedings did not differ significantly for predators fed at 2- through 16-day intervals. During oviposition, predators lost about 15 mg of body weight. Egg clutches comprised about 60% of the weight lost. Egg weights did not differ among treatments. The results suggest that P. maculiventris can survive long periods without prey, and adjusts its weight loss by reducing reproductive effort when prey become scarce. The importance of these adaptations for P. maculiventris to sustain populations in agricultural systems is discussed.