Volume 64 Number 10 Date 07/04/2019
SOYBEAN APHID - Densities have not increased noticeably since aphids were first observed on June 4. Counts averaged less than 9 aphids per 100 plants in 17% of the fields surveyed this week, and 83% had no detectable aphid population. Routine monitoring should begin by mid-July or once fields reach the R1 (first flower) development stage.
DEFOLIATORS - Leaf feeding by rose chafers, bean leaf beetles, sand chafers, slugs and various caterpillars is common in soybeans, though defoliation is light, ranging from 5-10% on no more than 2-3% of plants in most fields. The distinctive silver-spotted skipper caterpillar, recognizable for its two large orange eyespots on a dark purple head, was observed in Columbia County. Surveys indicate thistle caterpillars are prevalent again this season.
-- Krista Hamilton, DATCP Entomologist