David Owens, Extension Entomologist, owensd@udel.edu
Soybean
Continue scouting for podworm and stink bug in double crop beans. Stink bug thresholds increase to 7 once we move into R6.5, and up to 10 bugs/15 sweeps past R7. Podworms may still be present and active in double crop beans, especially the youngest beans. Also scout for defoliation. Soybean looper is active. A ballpark level of concern that NCSU uses for loopers is close to 1 looper per sweep. If loopers are present in your field and defoliation exceeds 20% and the beans have not yet reached R6, treatment may be advised. Loopers can be difficult to kill with insecticides, spinosyns, intrepid edge, and steward tend to be the most consistent products further south.
Alfalfa
A question came in last week about worms in alfalfa. A defoliation threshold that Texas A&M uses is 10% defoliation and greater than 7 defoliating worms per sweep.
Sorghum
Continue scouting for sugarcane aphid through the soft dough stage. We should be approaching that in the majority of late sorghum, but very late sorghum might not yet have reached soft dough. The threshold for sugarcane aphid is 30% of plants infested with areas of honeydew slicks present.
Small Grains
Small grain planting is right around the corner. Ask your seed dealer if your wheat varieties have tolerance to BYDV. Malt barley does not have tolerance to BYDV, an insecticide seed treatment will slow down aphid colonization, potentially as late as late Fall when cold weather slows aphid activity and reproduction down. Varieties without tolerance to BYDV or barley (and especially malting barley) should be scouted for aphids. For barley, Endigo is an excellent product offering long residual activity. For wheat, pyrethroids do a very good job on aphids, but the residual activity is not quite as long.