We need better knowledge on ecologically acceptable methods of managing introduced noxious weeds.

Hill, R. L.: Markin. G. P.: Gourlay, A. H.: Fowler, S. V.: Yoshioka, E. 2001. Host range, release, and establishment of Sericothrips staphylinus Haliday (Thysanoptera: Thripidae) as a biological control agent for Gorse, Ulex europaeus L. (Fabaceae). in New Zealand and Hawaii. Biological Control. 21: 63-74.

Markin, George P.; Nagata, Roddy F. 2000. Host suitability studies of the moth, Pyrausta perelegans Hampson (Lepidoptera: Pyralidae), as a control agent of the forest weed banana poka, passiflora mollissima (HBK) Bailey, in Hawaii. Proc. Hawaiian Entomological Society. 34: 169-179.

Redmon, S. G.; Forrest, T. G..; Markin, George P. 2000. Biology of Bruchidius villosus (Coleoptera:Bruchidae) on scotch broom in North Carolina. Florida Entomologist. 83(3): 242-253.

Coulter, Mel. 2001. Leafy spurge hit by beetle bombs. Programs & People: University of Idaho College of Agriculture Magazine. Winter 2001: 7-8.

Biological control is an important tool in managing noxious weed invasions in western Forests. Many of these weeds are particularly invasive following fire and compete with natural plant communities. We initiated new studies with support from the Fire Plan. We work with many cooperators in Eurasia, including Switzerland, France, Republic of Georgia, Bulgaria and Ukraine to understand the natural history of weeds and to search for biological control. A Bulgarian graduate student is studying the natural enemies of Rush skeletonweed in that part of its home range. We evaluate the host specificity and effectiveness of the agents in quarantine before releasing and monitoring them in the field. In Switzerland, we are studying the biology and learning how to propagate a root- feeding beetle for tansy ragwort. These colonies are being evaluated in quarantine. Typically, a complex of agents attacking different plant organs (flowering parts, stems, roots) is necessary for effective control. In NW Montana, we are assessing such a complex affecting tansy ragwort populations.

We cooperate with land managers in the release of new agents. With the Helena National Forest, we released a new biocontrol agent, a stem-mining beetle that attacks Dalmatian toadflax and set up vegetation monitoring plots to evaluate the impact of this insect on Dalmatian toadflax as it resurges in an area burned by wildfires in 2000.

We monitor previously released agents. Four years after the release of a foliage- feeding caterpillar on tansy ragwort in the Flathead National Forest, populations are now totally defoliating all tansy plants in wide areas around the original release sites. We released this agent on the Kootenai National Forest 2 years ago, and agents are already established.

We completed a cooperative research effort to implement an integrated pest management program for leafy spurge on the Sawtooth National Forest with Forest Health in R-4 and Range Management. High school students in Bozeman (the KidNappers project) introduced 4 biocontrol agents on spotted and diffused knapweeds. By this summer, three agents were so well established that knapweeds began to disappear at the release sites.