David Owens, Extension Entomologist; owensd@udel.edu
Soybeans
Continue monitoring fields for defoliation. Full season bean fields are in their early reproductive stages when defoliation thresholds decrease to around 15% of defoliation. Begin scouting fields for corn earworm. Corn earworm moths are unusually active right now. Adult moths prefer to oviposit in open canopy fields, and open canopy, drought stressed fields that have had recent insecticide applications are at greater risk. Worms can eat flowers without impacting yields because soybeans can compensate for flower feeding and soybeans produce more flowers than will become pods. However, economically damaging earworm populations may develop in soybean fields flowering at the beginning of a moth flight, because worms will be developing on small pods and pods developing seed. An economic threshold calculator is available to assist with management decisions. https://soybeans.ces.ncsu.edu/wp-content/uploads/2017/08/CEW-calculator-v0.006.html. While scouting for earworm, stink bugs may be observed. Stink bugs in flowering soybean are not injuring plants. Check plants again as pods begin developing to see if stink bugs are still present or if they have dispersed.