David Owens, Extension Entomologist, owensd@udel.edu
Alfalfa
There have been reports from other states of fall armyworm defoliating alfalfa. Another generation is hatching out of egg masses now, so be on the lookout for them during this week coming and the next.
Soybean
Continue scouting double crop beans for stink bug activity. Pay special attention to areas near woodlines, particularly woods with wild cherry and mulberry, as these are favored hosts of green stinkbugs. Stink bugs tend to aggregate in small but intense hot spots in a field. Thus, many times only a single pass or two are necessary.
Sod, Turf, and Pasture Grass
Scout all cool season grasses during the next two weeks for fall armyworm. Moths are emerging from pupae in the soil and laying eggs now. It takes them two weeks to fully develop. During the last three days of larval development they feed on more than 80% of their total food intake. Thus, by the time damage is noticed, most, if not all of the worms, have begun pupating. Use a soapy water flush to drive them out of thatch so that they can be seen easily. Use 1 tsp of lemon scented dish detergent per gallon of water, 1-2 gallons of water spread out over 1 square yard. This will likely be the last wave of fall armyworm before the season cools down and moth activity diminishes. They overwinter in Florida, advancing cool weather will clear them out of the area.
Fall armyworm egg mass hatching