Poplar Vagabond Aphid (Mordwilkoja vagabunda)

From: Ostry, Michael E.; Wilson, Louis F.; McNabb, Harold S., Jr.; Moore, Lincoln M. 1988. A guide to insect, disease, and animal pests of poplars. Agric. Handb. 677. Washington, DC: U.S. Department of Agriculture. 118 p.

Importance-  Colonies of feeding nymphs cause the new shoots to become distorted and produce galls rather than elongate into a branch. Heavy infestations distort entire trees. Injury is often restricted to a few trees.

Look For: Large convoluted green or brown galls (2 to 3 inches long) at the tips of the shoots.

Galls of poplar vagabond aphid.

Biology- The aphids feed on the growing shoots in the spring and form this unusual gall. The aphids vacate the gall in midsummer but return to it in the fall. Eggs overwinter inside the galls.

Monitoring- Inspect trees at any time for galls. Treat individual infested trees if galls become abundant.

Control:

• If practical, clip and destroy galls by hand.
• Apply an insecticide recommended for aphids in the spring to control emerging aphids.