Volume 58 Number 15 Date 08/15/2013
SOYBEAN APHID - Densities remain low in most Wisconsin soybean fields. The average count at 56 sites surveyed from August 6-14 was 22 aphids per plant. Only six fields had densities of 65-238 aphids per plant, while all others contained fewer than 35 per plant. Most soybeans will not require treatment this year, but exceptions will inevitably occur and fields must be evaluated in the next two weeks. The benefits of foliar treatment diminish beyond R5 (beginning seed) and control is not economical at R6 (full seed) or later.
JAPANESE BEETLE - This beetle is still common over a wide area of the state. Defoliation levels in Dane, Grant, Green, Iowa, Kenosha, Lafayette, Racine, Richland, Rock and Walworth counties varied from 2-20% in the past week, which is below the 35% threshold for soybeans in the seed-fill stages.
-- Krista Hamilton, DATCP Entomologist