David Owens, Extension Entomologist, owensd@udel.edu
Small Grain
As small grain planting season nears, be prepared to scout for armyworm and for aphids. Earlier planted small grain will have the greatest risk of both and of BYDV. The Hessian fly free date in Sussex County is historically October 10, although recent years have seen warmer ‘falls’. Joanne Whalen wrote in a 2015 article that historically we have Hessian fly biotype L in our area, and that there are wheat varieties resistant to this biotype, but it has been a long time since this was confirmed. In fields that are planted early and have had a history of BYDV, scout for aphids and be prepared to treat during the next 30 to 60 days. The aphid of greatest concern is the bird cherry oat aphid; winged females are black and the wingless forms are a dark olive green with redish coloration around the cornicles. English grain aphids are the most common species and are a lighter green with long, black cornicles. A common threshold is 20 aphids per row foot in the fall.
Soybean
Continue scouting double crop soybean for stink bug, soybean looper and corn earworm. Moths are still active, but attractive crop area is shrinking. The defoliation threshold for beans up to R6 is 15-20%, at R6 is 25%, and past R6.5 it is more than 50%. Stink bug thresholds similar change at R6 from 5 bugs per 15 sweeps to 7 bugs per 15 sweeps.
Sod/Pasture/Turf
Continue scouting for fall armyworm using lemony soapy water to flush out worms from thatch or sweep nets in pasture grasses. Thresholds for pasture grasses are 2-3 FAW per square foot or about 1 per sweep. Mississippi Extension advises that cutting can be an option if at or near threshold, but if it will be two or more days before the field can be cut, it is better to treat. Be prepared to scout any newly seeded grasses! Only a handful of armyworm are necessary to do significant damage to seedlings.