The soybean aphid, Aphis glycines, is a serious pest of soybean in Wisconsin and the upper Midwest. An import from China, the initial detection in 2000 of the soybean aphid in North America was in Wisconsin (Wedberg et al., 2001). Midwestern entomologists responded to the challenge of soybean aphid management by working together to determine a treatment threshold (Ragsdale et al., 2007) to use in conjunction with insecticidal control. In addition, research on soybean plant resistance is underway and is showing great potential as a tool for soybean aphid management (Hill et al., 2006a,b, Diaz-Martin et al., 2007). A third important management tactic, and the topic of this report, is biological control (or biocontrol) of the soybean aphid. We use the term biological control in its broadest context to include the actions of all types of aphid natural enemies – predators, parasitoids and pathogens – and species that are naturally occurring as well as those under human manipulation. We will focus our comments on predators and parasitoids. Soybean aphid is attacked by a number of pathogenic fungi (Nielsen and Hajek, 2005), but we have not observed pathogens to be a significant source of aphid mortality in Wisconsin.
Soil Science Extension
University of Wisconsin Madison