These aphids overwinter as adults on various weeds and field crops in or outside the orchards. Usually after pear bloom, when trees are growing rapidly, these aphids appear on foliage and shoots, establishing colonies and several generations may occur in cool spring weather. Although these aphids are frequently encountered in pear orchards, they seldom require special treatment unless the weather remains cool throughout spring and early summer.
Aphids generally serve as a valuable early season food source for insect predators.
With the onset of warm weather, aphids leave pear trees for other hosts and do not reappear until the following spring. Green peach aphid is light green in color. On adults a dark blotch in the middle of the abdomen serves to distinguish this species from others. Melon or cotton aphid is generally dark green, but immature forms may be yellowish. Bean or dock aphid is dark colored and seems to prefer sucker shoots in the center of the tree.