Multi-state comparison of aphid and aphid natural enemy community compositions in prairies

The advent of Aphis glycines (Hemiptera: Aphididae) in North America has significantly increased the use of insecticides in soybean in the North central region of the U.S. In response to the frequent outbreaks of A. glycines in soybean, a classical biological control program has been implemented. The program has resulted in the release of Binodoxys communis (Hymenoptera: Braconidae) for biological control of A. glycines in 2007. As a complementary portion of the biological control program, a multi-state survey of aphids and aphid natural enemies in prairies was conducted during 2006 and 2007. The survey’s objectives were to (1) study prairie aphid community structure before the release of B. communis and (2) identify potential non-target aphid species. Surveys were conducted in Indiana, Iowa, and Wisconsin. Aphids were surveyed from June through August through the use of transect sampling. The aboveground portions of all plants were visually inspected for aphids. In all, we identified more than 75 species of aphids. A total of 67, 49, and 15 aphid species including 15, 10, and 5 Aphis species were found in Indiana, Iowa, and Wisconsin respectively. Identified aphid natural enemies were utilized at identification levels common to all three states. A multivariate statistical analysis was used to distinguish differences in aphid and aphid natural enemy community compositions among the three states. The differences in community composition demonstrate the need to perform such multi-state investigations into the non-target impacts of B. communis.