Physiological age study of the consperse stinkbug, Euschistus conspersus (Hemiptera: Pentatomidae) in Fresno County, California

Changes in the physiological age of females in a population of consperse stinkbugs, Euachistus conspereus Uhler, in Fresno County, California, were followed through one annual cycle. The gonotrophic age techniques developed by Detinova (1945, 1959) and Rosay (in manuscript) for studying the age structure in mosquitoes and other Diptera were used in this study. The observed sequence of events in E. eonspersus was typical of many insects which overwinter as nulliparous females. The female becomes active in the spring, mates, produces a number of egg clutches and dies. By the end of July, nearly all of the new generation females have become multiparous, and their offspring form the overwintering generation. The fat body is readily observable in the females throughout the year. In the diapausing overwintering forma, the fat body changes color and becomes hypertrophied. These females do not mate until spring as shown by their empty spermathecae throughout the winter.