English grain aphid
Bright green with long black legs and black cornicles. English grain aphid is more common late in the growing season, and prefers to feed on the awns and wheat heads, and can result in damaged and damaged kernals. English grain aphid feeding typically does not cause direct damage, but can have an economic impact indirectly, by transmitting the virus Barley Yellow Dwarf Virus.
Source of information
online (http://entoplp.okstate.edu/ddd/index.html), modified from Department of Entomology (University of Nebraska), iWheat (Wheat Production and Pest Management Guide)