As they feed, aphids also inject saliva. This saliva cause some plants to develop curled, hardened or distorted growth. Overall plant vigor may suffer. They can be black, brown, yellow, red, gray or green. Most of the aphids are without a waxy covering, although the bodies of some of the woolly aphids are covered with white, waxy threads.
Some aphids have white spots or are completely covered with a white waxy powder.
The legs and antennae are usually long and fragile. Aphids may be wingless or may have functional wings. The offspring are smaller than the adults and are always wingless. While feeding, aphids inject saliva into the plant. The saliva of some aphids causes curled or distorted growth.