Ad 5F381A721F61FCD7021B759BC3645CDD1F4C3B88

Pest Information

Poplar Gall Aphid

Poplar Gall Aphid

  • Latin Name: Pemphigus spp.
  • Common Name: Poplar Gall Aphid
  • Latin Family Name: Aphididae
  • Other Names: Poplar stem gall, leaf petiole gall

Pest Details

Poplar Gall Aphid
Poplar Gall Aphid
Poplar Gall Aphid


There are several species of aphids in this genus, possibly native to North America, and found wherever poplar or cottonwood grow.


As with most aphids it is the eggs that over-winter, deposited by females on the bark of cottonwood trees. These hatch in the spring to nymphs that feed on the petioles (the stem) of new leaves, causing the stem to swell and create a gall that completely encloses the aphids. The next generation will include winged females that fly to the alternate host plants in the Mustard family, and several successive generations will feed on the roots of these plants. This may include various crop plants as well, allowing this aphid to be an economic pest. In the fall new winged females return to cottonwood trees to deposit their eggs. The gall is the most noticeable feature for this aphid, but it appears to cause little harm to the infested tree.


Identified by the swollen, light green gall on the petiole of cottonwood or poplar trees. If the gall is cut open it reveals dozens of small, gray, waxy aphids inside.

Characteristicts Important to Control:

Difficult to impossible to control once the gall encloses the aphids, but since infested cottonwoods suffer no damage from the gall control is not necessary at this stage. Control should focus on dormant oil applications in the winter, applied to the trunks and branches of the trees to smother the over-wintering eggs.

Related ProTraining Courses

Ad 41EBD59F92428E18914CABF5DD7F8E9E93AE28EA
Back to top