- Leafy Spurge
- Knapweeds
- St. Johnswort
- Yellow Starthistle
- Musk Thistle
- Canada Thistle
- Tansy Ragwort
- Toadflax
- Poison Hemlock
- Purple Loosestrife
- Educational Materials
(insect photographs)
Poison Hemlock Insects

The larvae of Agonopterix alstroemeriana, the Defoliating Hemlock Moth, chew numerous holes in the leaves and flowers of this weed. As the larvae mature, they form conspicuous leaf rolls at the top of the plant, feeding on seeds prior to pupation. Attacked hemlock plants are extensively defoliated and damaged. We formally offered this species but, because of health concerns for our collectors, in 2018 we have stopped collecting this moth.
Defoliating Hemlock Moth
Agonopterix alstroemeriana larvae (left) and damage (right).

Biological Control of Weeds, Inc.
1418 Maple Drive • Bozeman, MT 59715
Phone 406-586-5111

Email: bugs@bio-control.com