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Soybeans
Volume 58 Number 13 Date 08/01/2013 SOYBEAN APHID - Densities are still generally low for late July. The average count in 39 fields surveyed from July 25-31 was only 12 aphids per plant. The highest count documented was 180 aphids per plant in the Appleton area of Outagamie County. Foliar insecticides directed against this pest have been justified for only two soybean fields sampled by DATCP so far this season. JAPANESE BEETLE - This pest continues to cause light to moderate (5-15%) defoliation of soybeans, particularly along field margins. Infestations were noted in Brown, Columbia, Dodge, Sauk, Trempealeau and Winnebago counties this week. The economic threshold for Japanese beetle and other leaf feeding soybean pests is 20% defoliation between bloom and pod fill. Spot treatment is an acceptable form of control for fields with the heaviest injury occurring in the peripheral areas. GREEN CLOVERWORM - Larvae are widely distributed throughout the state, but populations are low (less than six per 100 sweeps) and leaf injury has been minor in surveyed fields. Defoliation has not exceeded the 20% treatment threshold thus far. -- Krista Hamilton, DATCP Entomologist 
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