David Owens, Extension Entomologist, owensd@udel.edu and Bill Cissel, Extension Agent – Integrated Pest Management; bcissel@udel.edu
The most economically important insect present in soybean fields right now is corn earworm. There are reports from south and southwest Delaware of a few fields above threshold. Pay special attention to late planted, open canopy fields. Pyrethroids should do a good job unless a field is 4x above threshold, in which case you may want to look at an alternative or additional mode of action. Stink bugs are present in low numbers in most fields, mostly greens but also with browns and the occasional brown marmorated. As a reminder, thresholds are 5 bugs in 15 sweeps, 2.5 for seed production. Defoliator complex members include green cloverworm, bean leaf beetle, aphids, and the occasional soybean looper. Virginia has been experiencing significant looper pressure in the last couple of weeks.
As you walk into fields, you may also see flagged leaves – 1 trifoliate that has wilted. This is a sign of possible Dectes infestation. Examine the wilted petiole where it would attach to the stem. If the petiole core is red and hollowed out, Dectes is present. Fields where you see a lot of this activity should be prioritized for timely harvest.