Life stage specific predation of Halyomorpha halys (Stål) by generalist predators.
Halyomorpha halys (Stål) is an invasive pest of agriculture in the USA. Feeding damage from H. halys affects dozens of crops yet little is known about the community of predators which prey on H. halys in its invaded range. Ten taxa of predatory or omnivorous insects were evaluated for their capacity to consume eggs and nymphs of Halyomorpha halys in laboratory mesocosm experiments. Predators were collected from agricultural ecosystems in New Jersey, starved for 24-48 h, and then exposed to H. halys eggs, first instar, or second instar nymphs. Survivorship of control prey in predator-excluding containers within the arenas was compared to that of predator treatment groups to determine the effect of predator presence. Stage-specific differences in H. halys survivorship among life stages were observed for several predator taxa indicating stage-specific predation. Acrididae, Coccinella septempunctata (L.), Podisus maculiventris (Say) (nymphs and adults), and Tettigoniidae reduced the hatch rate of H. halys eggs. Hemipteran predators, including Nabis spp. and Reduviidae, reduced the survivorship of first instar nymphs. Similarly, Nabis spp. and P. maculiventris nymphs reduced the survivorship of second instar nymphs. Acrididae, Nabis spp., P. maculiventris nymphs, Reduviidae, and Tettigoniidae showed stage-specific tendencies in their consumption of H. halys. Morphological similarities between the immature stages of H. halys may facilitate predator suppression of these mobile stages. These results indicate that predation estimates that rely solely on sentinel egg masses may underestimate the impact of generalist predators on other H. halys life stages.