The pentatomid hunters: molecular tracking of predation on stink bugs (Hemiptera: Pentatomidae) in cotton and soybeans

Stink bugs (Hemiptera: Pentatomidae) have emerged as significant pests of cotton and soybeans in the southeastern United States with losses exceeding $70 million annually. Three of the most prominent pests are the southern green, Nezara viridula, green, Chinavia hilaris and brown stink bug, Euschistus servus. However, their predators are poorly understood, especially in respect to early season predation. As field observation of predation is difficult, molecular gut content analysis offers an alternative to traditional approaches. Consequently, species-specific 16S molecular markers were designed and used to discern the gut contents of potential predators of stink bugs. Various predators were collected throughout the summer in cotton and soybean in southeastern Georgia, and predation frequency was examined relative to prey availability. Predation rates were significantly higher on N. viridula than on E. servus and C. hilaris, despite relatively similar availability of all prey resources. Our results showed that N. viridula was consumed primarily by the predators Coleomegilla maculata, Geocoris punctipes, and Notoxus monodon, with up to 40% positive in July. These data suggest generalist predators could provide valuable biological control of stink bugs, but additional research examining the spatio-temporal nature of predator-prey interactions is required to understand the structure of such food webs relative to pest management.