Corn aphids
Rhopalosiphum maidis

Corn leaf aphids are small to medium and bluish green in color and also infest small grains. 

This aphid infests all parts of the corn plant above ground. The most severe damage occurs to the tassel, often aphid populations become so dense within the protective sheath of the tassel that proper pollination does not occur and incomplete ears result. Leaves may become encrusted with aphids and wilt. Under sever conditions leaves will be dry and chlorotic.

Corn leaf aphid excretes copious amounts of honeydew. This honeydew may attract attending ants, serve as media on which sooty mold may grow, and provides food for corn earworm moths and other pests of corn.