David Owens, Extension Entomologist, owensd@udel.edu
Some of the early corn is beginning to tassel, and other fields are approaching tassel. Scout fields, particularly those close to wheat fields, for stink bugs. V14 to VT thresholds from NCSU (https://corn.ces.ncsu.edu/2020/05/important-changes-for-stink-bug-thresholds-in-corn-for-2020/) are 10 stink bugs per 100 plants at this stage. If stink bugs are observed, bifenthrin is the only pyrethroid that has decent brown stink bug activity. Japanese beetles are becoming active. I have not seen numbers high enough to cause significant damage by feeding on silks or leaves, although defoliation hotspots near field edges have been observed in previous years.
Soybeans
Spider mite activity has been increasing in fields, but recent wet and cool weather may retard them and stimulate beneficial fungal pathogens to take them out. Monitor defoliation levels and consider a treatment if defoliation reaches or exceeds 30-40% of the total crop canopy. Thus far, no reports of heavy feeding have been received.