May 11, 2007

Oat-bird cherry aphid

Greenbug

I have received a few calls from southeastern and central Nebraska reporting aphids in wheat. In one case it was thought they were oat-bird cherry aphids. I have not received any samples, but greenbugs are another possible aphid in wheat at this time of year.

Often in Nebraska spring aphid populations are controlled by natural enemies such as lady beetles and parasitoid wasps. To determine if it is worth treating for aphids, it is necessary to determine the identity and number of aphids present. When scouting for aphids in wheat, estimate the number of aphids per stem at several locations in a field. Don't just count aphids in the "hot spots" because you need to get an estimate of the overall aphid population in the field.

Treatment threshold levels vary by aphid species and plant growth stage (Table 1)

Insecticides

A variety of effective insecticides are available for aphid control on wheat. Check the Department of Entomology Web site at http://entomology.unl.edu/instabls/waphids.htm for a list of rates and restrictions for suggested insecticides for aphid control in wheat.

Additional information on aphids in small grains, including photos of common species and a key for their identification, can be found in NebGuide G1284, Cereal Aphids.

Bob Wright
Extension Entomologist