Soybean aphid populations have been relatively low this growing season, but growers searching for the damaging pest are reporting another pest that looks surprisingly aphid-like.
Jenny Mennenga, Syngenta Seeds agronomist, led growers to the soybean field August 18, during a field day in Pekin, Ill. Shaking plant leaves, a small flurry of insects fill the air around us. “Let them settle a bit and you’ll see they aren’t aphids, but whitefly,” says Mennenga.
Whiteflies have historically been major pests in greenhouse plants, commercial vegetables and cotton. Searches of the literature find the pest has caused economic damage to soybean in southeastern Australia. Yield reductions from heavy populations have also been reported in Florida and Georgia. However, despite some reports in recent years in Illinois and Iowa, little is known about their potential in Midwestern soybeans.
Mennenga says the levels she is seeing aren’t causing economic damage.
Whitefles are similar to aphids in that they have high reproductive potential and are notorious for quickly developing resistance to insecticides. Yield loss comes when they insert sucking mouthparts into the leaf and remove sap from the leaves. The insects can produce honeydew that creates a sooty mold on the leaves of the plant.
One of the easiest places to find the critters is on the underside of velvetleaf (buttonweed) leaves.
Keep an eye open for this aphid mimic and consult your state extension agronomist if you are experiencing heavy whitefly populations.