David Owens, Extension Entomologist, owensd@udel.edu
Soybean
Continue scouting double crop soybean for stink bugs and late season looper defoliation. Soybean looper activity has been increasing in Virginia, and soybeans even at the R6 stage can still be hurt by defoliation. North Carolina considers a concerning number of loopers near 1 per sweep. Steward, Intrepid Edge, and Denim are the most effective products for loopers. Stink bug thresholds increase to 7 by late R6 stage.
Sorghum
Continue scouting late sorghum for sugarcane aphid. The threshold is 30% infested plants with areas of localized honeydew present. The most effective aphid products are Sefina, Sivanto, and Transform.
Alfalfa
Another report came in this week of worm activity in alfalfa, this time fall armyworm. A reasonable threshold is 10% defoliation with worms present. A better alternative to spraying alfalfa would be to make its final cut of the season and let it regenerate a little as it heads into winter.