I just got a report of a soybean aphid infestation in Essex County. It has been several years since we have seen soybean aphid in Virginia, but the summer conditions (generally cooler, overcast) favor development of that pest. Reports of spotty infestations are also coming in from other states, North Carolina included.

As a reminder, the current economic threshold for aphids is an average of 250 aphids per plant, on two consecutive field visits spaced about 5-7 days apart (hit the ‘more’ button for more). This is because aphid populations can ‘crash’ quickly due to heavy pressure by natural enemies like lady beetles, parasitic wasps, and fungal diseases. When scouting, choose a ‘Z’ or ‘W’ shaped pattern to cover the entire field and sample at last 20 to 30 plants per field by examining the entire plant including stems and upper and lower leaf surfaces. Use the aphid/plant average for determining the need for treatment. The threshold applies to soybean through the R5 growth stage (3 mm long seed in the pod at one of the four uppermost nodes on the main stem), after which time plants can tolerate 1,000+ aphids with no threat to yield.
Additional information: soybean-aphid-threshold-ppt