Pea Aphid Control

Host Plants

• Pea aphids are commonly found in all the alfalfa and peas growing regions in the United States and Canada. Other host plants of the pest include sweet clover, leguminous weeds and field peas. The insects frequently overwinter in crimson clover and vetch. In areas with mild winters, the insects also overwinter in debris on the ground. The eggs remain unaffected even in severe winters though the adult insects die.

Description

• The adult aphid is light to dark green colored with reddish eyes, measuring less than ¼ inch in length. The wingless pests have long and slender, tailpipe like projections growing from the abdomen. The tiny eggs are light green in color and change to a glossy black before hatching. The nymphs are similar in structure to the adults, only a little smaller in size.

Damage

• Like other species of aphids, pea aphids are also primarily sap sucking pests that feed on plant juice from tender plant areas. Damage is characterized in the form of deformed and wilted plants. Heavier infestation can kill plants entirely. Infested plants have a shorter height and a more bunch like, lighter colored growth. Brown colored spots are often seed on wilted areas. As they feed, the pests secrete sticky honeydew that promotes the growth of sooty black fungus on infested areas. Pea aphids are also vectors of the pea enation mosaic and the yellow bean mosaic viruses.

Damage

• Introducing natural predators into infested plants is usually sufficient to keep pea aphid populations under control. These include many species of lady beetles and parasitic wasps. The use of pesticides is recommended when weather conditions do not support the presence of natural predators, especially lady beetles. Chemical control options include products containing malathion, methomyl or dimethoate.