Nov. 11, 2014

Aphid infestations have been recently reported in winter wheat in four counties in South Dakota (SDSU iGrow Report) and one county in Kansas (KSU Kansas Insect Newsletter). While it is rare to see economically damaging levels of aphids this late in the year, warmer fall temperatures likely have promoted aphid population growth in some areas. However, with colder weather approaching, it is unlikely that aphids will need to be treated in Nebraska wheat this fall. (See the High Plains IPM Guide for treatment thresholds.) Aphids are able to survive a few hours below freezing, but a hard freeze should cause significant mortality.

However, scouting winter wheat fields for aphids and identifying which aphid species are present in the fall can be important for understanding disease risk next spring. Bird cherry-oat aphid, corn leaf aphid, English grain aphid, and greenbug can vector Barley Yellow Dwarf Virus in wheat and barley. This disease is usually not serious in Nebraska; however, in some years it can be significant. For help in identifying aphids in Nebraska winter wheat see the Cereal Aphids NebGuide (G1284). More information on Barley Yellow Dwarf Virus is in NebGuide (G1823). 

Julie Peterson, Bob Wright, and Jeff Bradshaw
Extension Entomologists