Origin:
Native to Europe, but now found throughout the world, including throughout the U.S. and on every island of Hawaii.
Biology:
A serious pest of agricultural crops, causing leaf distortion, stunting of young plants, and unmarketable produce. They form dense colonies, and are major pests of Kohl crops such as cabbage, broccoli, cauliflower, or brussels sprouts, where they may feed deep within the folds of the leaves, making control difficult. They are known vectors of many viruses of plants. The life cycle is typical of aphids, with eggs over-wintering in cool climates, nymphs emerging in the spring to wingless females which produce living offspring asexually, winged forms developing in the early summer to migrate to new plants, and winged males and females showing up in the fall to mate and produce new eggs. In warm climates there may be no eggs, but just continuous generations of the aphids.
Identification:
Small aphids that are greenish gray and with a light coating of wax over them.
Characteristicts Important to Control:
Principally a pest of agricultural crops, and control is a combination of cultural methods, use of biological controls and natural enemies, and properly timed applications of insecticide.
