Insect identification > Homoptera > Aphids > Apple aphids

Apple aphids


The apple aphids. - There are three species of aphids which attack the apple more or less generally throughout the United States and a fourth is injurious in some parts of the country. In addition, a woolly species, feeding on both the twigs and roots, is of importance.

The three species referred to are the apple aphid (Aphis pomi De G.), the rosy apple aphid (Anuraphis roseus Baker) and the apple grain aphid (Rhopalosiphum prunifoliae Fitch), the last formerly believed to be the same as a European species and called the European grain aphid. All three lay their eggs in the fall on the twigs of the apple.

In the spring these hatch and the young feed on the buds and opening leaves and grow into stem mothers.

The apple aphid stem mother has a uniformly green body, brown head and long, dark cornicles : the rosy apple aphid stem mother is greenish, blended with purplish brown and the cornicles are long, slender and dark, the body so dark as to be often described as blue; the apple grain aphis stem mothers are yellowish green with a broad darker green stripe along the middle above, from which several side branches pass off, and with rather short, stout, yellowish corniclees.

The feeding of the aphids on the developing leaves in the case of the rosy apple aphid causes these to curl greatly, but with the apple aphid this is usually less marked and with the apple grain aphid it does not occur.

After a generation or two on the apple, winged forms begin to appear and these migrate to summer food plants. The rosy apple aphid passes to species of plantain, particularly the narrow-leaved plantain; the apple grain aphid migrates to small grains such as wheat and oats; the apple aphid, however, may migrate to any of a long list of plants for the summer, but some usually remain on the apple.

On these summer food plants, generation after generation is produced, but in the fall a migration back to the apple occurs and here both sexes are produced and eggs are laid which hatch the following spring.

In some cases the apple grain aphid may winter on the grain, close to the ground, not returning to the apple. During the summer months the rosy apple aphid in its winged form has a pinkish or reddish body which has led to its being given its common name.

The widely distributed clover aphid (Anuraphis bakeri Cowan) which at times causes serious loss to the clover seed crop in the West generally lays its eggs in the fall on the apple, pear, hawthorn or rosaceous plants but after a few generations there in the spring it passes to clover, alfalfa or shepherd's purse for the summer.

The chief injury to the apple by these insects is that growth of the buds and leaves is often checked and the latter may become hard, malformed and grow but little.