The first spring adults are winged females which fly in search of suitable host plants, sometimes migrating far northward. Shortly thereafter, they give birth to live nymphs which usually develop into wingless females. Under favorable conditions, more winged females develop and migrate. Males are rarely found but females continue to reproduce without mating. No egg stage is known.
Reproduction slows down in winter and summer and is most rapid during cool weather.
Therefore, corn leaf aphids tend to be a problem on winter grains in spring and on late-planted corn in fall. The number of generations per year varies from 9 in Illinois to 50 in southern Texas. Corn leaf aphids rarely require control in North Carolina because high temperatures and natural enemies reduce aphid populations in summer. Should damaging aphid populations develop, consult the current North Carolina Agricultural Chemicals Manual .