Apple aphid (Aphis pomi)
Potato aphid (Macrosiphum euphorbiae)
Pest description and damage Several species of aphids may feed on the foliage, stem, and flower clusters. They have piercing-sucking mouthparts and generally exude honeydew. The potato aphid is green, yellow or pink in color and has long cornicles ("dual exhaust pipes"). The winged adults are yellowish with whitish wings. These potato aphids cause the leaves toward the tips of the twigs to turn yellow and twist. They also are a serious pest in the vegetable garden so controlling the aphids on cotoneaster may reduce problems elsewhere. The apple aphid (often called the green apple aphid) is primarily a pest of apples but affects other rosaceous hosts. Green apple aphid is a tiny green aphid with visible cornicles. The winged form has a darker thorax, greenish abdomen, and whitish wings. This aphid feeds in clusters on leaves and around the developing fruit. It is nearly indistinguishable from the spirea aphid and is often treated the same. Aphids produce copious amounts of honeydew that gardeners find objectionable.
For biology, life history, monitoring and management
Both aphids appear in the spring when cotoneaster is blooming, so take care to choose a pesticide that is harmless to bees.
See "Aphid" in:
For more information
Beers, E.H., S.C. Hoyt and M.J. Willette. 1993. Apple Aphid and Spirea Aphid (http://jenny.tfrec.wsu.edu/opm/displaySpecies.php?pn=380).
Berry, R. and G. Bishop. Potato Aphid. Insects of Economic Importance. Oregon State University (http://ipm-dd.orst.edu/potato/potatoaphid.pdf).