On June 18, 2001 Brian Lang, extension specialist in crops, found soybean aphids on V1-stage soybean plants near Decorah in northeastern Iowa. He noted that aphids were common in fields in river floodplains. The highest density was 20 aphids per plant and most of the aphids were clustered on the youngest unexpanded trifoliate leaf. He did not find aphids on hilltop fields even though the fields had woodlands nearby that might harbor their alternate host, buckthorn. Next week I will have additional information on aphid biology, scouting, and management decisions.
This article originally appeared on page 125 of the IC-486(15) -- June 25, 2001 issue.