Invasive Plants in PNW Ecosystems
|
Developing a Biological Control Program for Invasive Knotweeds (Fallopia spp.).Fritzi Grevstad, Olympic Natural Resources Center, University of Washington, 2907 Pioneer Road, Long Beach, WA 98631, (360)642-3920, grevstad@u.washington.edu A classical biological control program is being developed for Japanese and giant knotweeds (Fallopia japonica and F. sachalinensis) and their hybrid (F. x bohemica) in North America. Knotweeds are listed among the world’s worst invasive plants and are particularly problematic along streams and rivers of the Northwest and Northeastern coastal areas of North America. The steps in developing a biological control program include surveys of the natural enemies already using the target weed, foreign exploration for new natural enemies (candidate biocontrol agents) from the weed’s native range, host specificity testing of candidate agents, safety review by the Technical Advisory Group, acquisition of state and federal permits, and finally, if approved, release and monitoring of biocontrol agents. The search for knotweed-specific natural enemies will follow up on extensive research already carried out for a biological control program against knotweeds in the United Kingdom. Much of the required foreign exploration and initial testing has already been carried out, substantially reducing development costs. Among the more promising candidate biocontrol agents are a leaf-feeding chrysomelid beetle Gallerucida bifasciata, a sap-sucking psyllid Aphalara itadori, a stem-boring weevil Lixus impressiventris, and a leafspot pathogen Mycosphaerella sp. These organisms will be imported first into an escape-proof quarantine facility where they will be tested for their ability to feed on ~60 related native and economically important plant species. Provided host specific natural enemies are used, biological control can be a safe, effective, and highly economical means of long term control of environmental weeds.
|
||
|