David Owens, Extension Entomologist, owensd@udel.edu
Sorghum
For the first time in several years, we have significant sorghum aphid populations at the research station. Thresholds in southern states are 30% infested plants with a dime sized or greater colony of aphids and localized areas of honeydew present. If late sorghum has significant honeydew present and the sorghum is drought stressed, a treatment may be justified. Sivanto and Transform are the only recommended materials.
Soybean
Continue scouting double crop soybean for podworm. We just evaluated a spray trial installed last week. Pyrethroids alone provided anywhere from little to 60% control. In our trial, we are still finding very small worms indicating continuing or very recent moth activity.
Stink bugs may also be a threat in double crop and late full season bean fields. Once we get to R6.5, thresholds rise to 7 stink bugs per 15 sweeps. Remember to check the interior of a field if there are significant number of stink bugs on the edge of the field before making treatment decisions. Also identify which species are present. Brown and brown marmorated stink bugs are most susceptible to bifenthrin.