Many species of Aphids or plant lice occur on ornamental trees and shrubs in Pennsylvania. Certain species feed on foliage, others on twigs and branches, flowers or fruit, and some on roots. They feed on both coniferous and deciduous plants. Effective control of Aphids has been a problem to homeowners and landscape managers for years. Some of the more common Aphids include the Green Peach Aphid, Melon Aphid, Tuliptree Aphid, Giant Bark Aphid, White Pine Aphid, and Rose Aphid.
Aphids constitute a large group of small, soft-bodied insects.
They may measure up to 6 mm in total length. Aphids have piercing-sucking mouth parts which enable them to remove plant fluids from a host. Aphids generally can be recognized by their pear-like shape, a pair or cornicles at the posterior of their bodies and fairly long antennae. Aphids vary in color from green, yellow, red, purple, brown or black. The life history of many Aphids is complex and unusual.