Pacific Northwest Insect Management Handbook

Black locust (Robinia)-Aphid

Cowpea aphid (Aphis craccivora)

Pest description and damage These aphids range in size from 0.05 to 0.08 inches in length and vary in color progressing from light greenish-gray through darkening shades of green to shiny black as they molt. The four molts leave abundant white cast skins among the living aphids and honeydew. Feeding results in puckering, stunting, and curling leaves, and pods, covered with copious sticky honeydew and sooty mold.

Biology and life history Overwintering eggs hatch on alternate hosts such as alfalfa in spring. Shortly after, alates (winged females) fly to black locust and other hosts. Parthenogenetic females lay over one hundred eggs and there may be up to twenty generations.

For biology, life history, monitoring and management

See "Aphid" in:

Common Landscape Pests

Management-chemical control

See Table 1 in:

Chemical Control of Landscape Pests

Use pesticides safely!

Wear protective clothing and safety devices as recommended on the label. Bathe or shower after each use.
Read the pesticide label—even if you’ve used the pesticide before. Follow closely the instructions on the label (and any other directions you have).
Be cautious when you apply pesticides. Know your legal responsibility as a pesticide applicator. You may be liable for injury or damage resulting from pesticide use.

Trade-name products and services are mentioned as illustrations only. This does not mean that the participating Extension Services endorse these products and services or that they intend to discriminate against products and services not mentioned.