Natural Biological Control of Stink Bug Heteroptera Pentatomidae Eggs in Corn, Peanut, and Cotton Farmscapes in Georgia
Environmental Entomology 40(2): 303-314
In southeastern United States farmscapes, corn, peanut, and cotton fields are often closely associated with each other. Thus, this 5-yr study was conducted to determine parasitism and predation of sentinel and natural occurring Euschistus servus (Say) and Nezara viridula (L.) egg masses in farmscapes in Georgia. A variety of parasitoids including six scelionids, Trissolcus basalis (Wollaston), T. brochymenae (Ashmead), T. euschisti (Ashmead), T. thyantae Ashmead, Telenomus podisi Ashmead, and Gyron obesum Masner, and one encyrtid, Ooencyrtus spp., was recovered from E. servus and N. viridula eggs, but overall the greatest diversity of parasitoids emerged from stink bug eggs in corn. Only T. basalis and T. podisi parasitized both N. viridula and E. servus eggs in all three crops over all farmscapes. A wide variety of predators, including Orius insidiosus (Say), Geocoris punctipes (Say), G. uliginosus (Say), Coccinella septempunctata (L.), Hippodamia convergens Guerin-Meneville, Harmonia axyridis (Pallas), Coleomegilla maculata (De Geer), Scymnus loewii Mulsant, Scymnus ardelio Horn, and Solenopsis invicta Buren, preyed on stink bug eggs in each crop. When differences were detected, generally percent parasitization per egg mass was higher than predation in corn, and percent predation was higher than parasitization in peanut. Overall, percent predation per egg mass was higher than parasitization in cotton, but on one occasion percent parasitization was higher than predation in cotton associated with corn. Seasonal occurrence and abundance of natural enemies, levels of parasitization and predation of stink bug eggs, and percent egg predation by sucking and chewing predators indicated that natural enemies of stink bug eggs disperses from crop to crop in the farmscapes. Stink bug egg predators and parasitoids are likely responding to host plant switching by their prey or hosts. In conclusion, this study has shown that natural enemies of stink bugs are prevalent and important biological control agents in these farmscapes.