Development, Survival, and Reproduction of Geocoris punctipes (Hemiptera: Lygaeidae): Effects of Plant Feeding on Soybean and Associated Weeds

Abstract

Effects of plant feeding on the biology of the insect predator Geocoris punctipes (Say) were examined in the laboratory. Supplementing a prey diet with plant food resulted in shorter developmental times for certain instars, greater nymphal survival, and increased weight of newly emerged adults. Plant food alone was sufficient to sustain first instars for a short period and allowed some development to the second instar, but was not sufficient for sexual maturation and oviposition and did not significantly increase the fecundity of mature adults compared with a water control. Plant feeding, serving as a moisture source, allowed adults resulting from prey-fed nymphs to survive for a limited time in total absence of prey, while limited consumption of prey in early adult life more than doubled longevity of adults restricted to plant-only diets. Effects of particular plant species were variable, depending on developmental stage and sex. A seed diet of green bean was superior for adult longevity in the absence of prey but was less suitable than many plant foliage diets for nymphs. G. punctipes appears to be able to draw moisture and nourishment from a wide variety of herbaceous plants, an ability that may increase developmental and survival rates in periods of prey abundance and may represent an important means for dealing with periods of prey scarcity.