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Soybeans
Volume 60 Number 11 Date 07/02/2015 SOYBEAN APHID - Levels of this insect remain well below the economic threshold of 250 aphids per plant and over 85% of the soybean fields surveyed in the past two weeks still had no detectable population. Average counts at the sites sampled from June 25-July 1 were less than five aphids per plant and 35 per infested plant, based upon examination of 100 plants per field. The highest total count was 350 aphids on 10 of 100 plants in (3.5 per plant) in a field near Black River Falls in Jackson County. Despite the low sample numbers, aphid populations could increase rapidly in flowering soybean fields and economic densities may develop later this month. This pest requires consistent monitoring from now until the R5.5 stage of soybean growth in August. DEFOLIATORS - Defoliation is common but light, ranging from 2-25% on 10-20% of plants in most surveyed fields. The leaf feeding insects observed during recent surveys were the rose chafer, bean leaf beetle, Japanese beetle, slugs and various caterpillars. Slug feeding damage was most prevalent. Defoliation rates have not exceeded the 30% economic threshold for soybeans in the pre-bloom vegetative stages as of July 1. -- Krista Hamilton, DATCP Entomologist 
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