Soybean aphid: distribution and impact on soybean

On June 16, Brian Lang, extension specialist-field crops, found soybean aphids on V2-stage soybean plants 3 miles southwest of Decorah in northeastern Iowa. Aphids were very uncommon and Brian described finding them like looking for a needle in a haystack. The aphids were first found by following a trail of ants to the plant were the ants were collecting honeydew from the aphids. The highest density was 30 aphids per plant but aphids occurred on less than one plant out of 100. Most of the aphids were clustered on the youngest unexpanded trifoliate leaf