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.