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

The defoliating Klamath Weed Beetle, Chrysolina quadrigemina, feeds on the foliage of this weed in both the adult and larval stages. The Klamath Weed Beetle has dramatically reduced the abundance and density of this weed in areas where fall temperatures are mild. This biological control agent is responsible for contributing to the impressive decline in St. Johnswort in the Pacific states. Releases of 105 adults are available during June and July for $100.00.

St. Johnswort Defoliating Inchworm
Aplocera plagiata

Aplocera plagiata, the St. Johnswort Inchworm, lays about 300 eggs onto the leaves of this poisonous perennial weed. The larvae that hatch from these eggs feed on the leaves and defoliate the plant. Two generations often occur with this species able to withstand high and low temperature extremes and dry habitats. Releases of 105 larvae are available in July for $75.00.

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

Email: bugs@bio-control.com