I Didn’t Know That!
- 2025-07-07
- By Martha Kirk
- Posted in Horticulture, The Garden Buzz
By Phil Schreiner, Colorado Master Gardener
Poplar Twiggall Fly

The gall-forming larvae of this insect are a common problem for Front Range aspens. Foremost, when evaluating this pest, it is important to note that the tree can deal with the damage caused, and, if otherwise well cared for, it will continue to thrive. The galls of the twiggall fly larvae are primarily an aesthetic issue.
Parasitic wasps and birds like the chickadee are twiggall larvae predators and help to reduce the impact of this pest. Systemic insecticides have marginal efficacy and are not usually effective. Numerous galls on an individual branch can look unattractive and also weaken the branch. Pruning the affected branch can improve both the structure of the tree and its overall appearance.
Read more about Poplar Twiggall Fly here.

