Effects of mating status on body weight, oviposition, egg load, and predation in the predatory stinkbug Podisus maculiventris (heteroptera: pentatomidae)

Abstract

Effects of mating on body weight, oviposition, and egg load in the predatory bug Podisus maculiventris (Say) were studied in the laboratory using the greater wax moth, Galleria mellonella L., as prey. In the early stage of adult life (i.e., from day 3 to 10), mated females had higher body weights than unmated ones. Mated females produced about twice as many eggs as virgin females but longevity was similar. Unmated predators oviposited less frequently and later in life than mated predators. High egg loads found in 7-d-old unmated females suggested that mating in the genus Podisus stimulates egg deposition rather than oogenesis. Results are compared with previous studies on the life history of the predator under laboratory conditions. Females of P. maculiventris in our study had markedly higher body weights and fecundity rates than those in other studies. Approximately 10-15% of P. maculiventris females succeeded in mating with males of the smaller-sized Neotropical species Podisus nigrispinus (Dallas). Such females initiated oviposition at the same time after mating as females mated with conspecific males. Their fecundity was intermediate between that of virgin females and females mated with conspecific males, but none of their eggs developed. Mating status had a significant impact on predation and consumption of caterpillars of beet armyworm, Spodoptera exigua (Hübner). Mated females of P. maculiventris attacked and consumed 3-4 times as many prey as unmated females. The implications of these findings for evaluating the reproductive and predatory potential of this pentatomid are discussed.