Cereal Aphids

suctorial plant-eating insects of the sub-order Aphidodea of the order Homoptera. They are cereal crop pests. The most harmful are Schizaphis gramina, which is widespread in southern Europe, Africa, Asia, America, and the steppe and forest-steppe zones of the USSR;Macrosiphum avenae, which is found north of the tropic of Cancer, in Eastern Africa, and throughout the USSR; Brachycolus noxius, which is found in Western Europe, Southwest Asia, Africa, and the steppe and forest-steppe zones of the USSR; and the common bird-cherry aphid (Rhopalosiphum padi), which is found on all continents and in all parts of the USSR.

The eggs hibernate on winter crops and in wild cereals and on the bird cherry in the case of the common bird-cherry aphid. In spring the larvae hatch, soon turning into wingless stem mothers which bear 25 to 30 larvae parthenogenetically. During the growing season cereal aphids produce ten to 15 generations, which develop on cereals (first on spring grain crops, then on cereal grasses, on sprouting fallen grain, and on the shoots of winter crops). In summer, when plants become coarse, winged virgin female cereal aphids appear among the wingless ones, and the winged aphids fly on to new areas. In September and October a sexual generation of males and females is produced. The fertilized females deposit eggs which hibernate. Leaves damaged by cereal aphids turn yellow and wither, plant growth is inhibited, and the plants often die. Means of controlling cereal aphids include early planting of spring grain crops; the application of fertilizers to the soil, especially phosphorous and potassium fertilizers; shallow plowing of stubble; deep fall plowing; and the use of insecticides on plantings.