Once again, Drs. Dave Voegtlin (retired entomologist, Illinois Natural History Survey) and Dave Hogg (Professor of Entomology, University of Wisconsin) conducted their annual spring survey of soybean aphids. From May 12-17, they looked for soybean aphids on the primary host — common buckthorn, Rhamnus cathartica. At some sampling locations, they also examined the glossy buckthorn, Frangula alnus. The overall assessment by these entomologists — there were fewer soybean aphids this spring as compared with the previous 2 years. Sampling occurred in the following states: Illinois, Indiana, Iowa, Michigan, Ohio, and Wisconsin. At these seven locations, also sampled in previous years, soybean aphids were found at only two sites. In 2013, soybean aphids were detected in six of the seven sampling sites. Near the Quad Cities, soybean aphids were found at two of the three locations surveyed. The number of aphids within the colonies was low.
These results suggest that soybean aphids are off to a slow start this spring. This is not surprising based upon the very cold and prolonged winter of 2013-14. A mild summer could still result in soybean aphid outbreaks in some fields. If hot and dry conditions dominate the summer weather, soybean aphid densities should remain below economic levels in many areas of the Midwest.
I extend my thanks to Dave Voegtlin and Dave Hogg for generating these survey results.