Arthropod predator community associated with soybean gall midge, Resseliella maxima(Diptera: Cecidomyiidae), in Minnesotan soybean fields

The soybean gall midge, Resseliella maximaGagné (Diptera: Cecidomyiidae), is a pest that injures soybeans in the Midwest United States. Little is known about the natural enemies of R. maximaor the potential for biological control. Therefore, we performed a 2-yr survey in Minnesota to examine the predator community associated with R. maximainfestations. We found that Orius insidiosus(Say) (Heteroptera: Anthocoridae) and Pterostichus melanarius(Illiger) (Coleoptera: Carabidae) were the most common foliar- and ground-foraging predators, respectively. Some of the commonly encountered predator species were tested in laboratory predation experiments. Harmonia axyridis(Pallas) (Coleoptera: Coccinellidae) and O. insidiosusrepresented the foliar-foraging predators tested, and H. axyridisconsumed significantly more R. maximalarvae than O. insidiosus. Among the ground-foraging predators, 4 carabids were tested. Poecilus lucublandus(Say) (Coleoptera: Carabidae) and Pt. melanariusconsumed significantly more R. maximalarvae than Poecilus chalcites(Say) (Coleoptera: Carabidae) and Bembidion quadrimaculatum oppositum(Say) (Coleoptera: Carabidae). We conclude that Pt. melanariusshould receive further attention as a potential biological control agent of R. maxima, due to its high abundance in the soybean fields in this study, temporal overlap with the pest, and high propensity to feed on the pest.