The production of young usually begins 2 or 3 days after the last molt and continues without interruption for over a month. A single female produces an average of about 185 young. Normally, the period of reproduction extends from about pink to June 20 or later. Usually the maximum period of productive activity is around the last week of May and the first week of June. This is usually the period when young fruits are beginning to set and to start active growth.
Populations are usually greatest in the inner and upper parts of the canopy.
There are approximately three generations produced on apple with the second generation occurring 2 to 3 weeks after petal fall and the third generation appearing by mid- to late June. By early to mid July all aphids have developed into alates and have dispersed from apple to summer hosts. These females produce wingless oviparae, which mate with returning winged males from the summer hosts. The mated females deposit an average of 4-6 overwintering eggs, usually in late October and November. They secrete large quantities of honeydew which provides a substrate for a black sooty fungus which can affect fruit finish.