| "I decided the only way we could get a lot of beetles out quickly was to get more help. I went to the public and started asking ... if they would be interested in rearing some of these beetles, and paying the costs of doing it themselves." | |
| Brock Woods, Wisconsin Department of Natural Resources |
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Researchers in Wisconsin are successfully getting the public to raise bugs, and to pay for the opportunity to do it. The resulting population of imported insects is proving to be an effective, natural control for the invasive weed purple loosestrife, which has become a serious threat to the state's wetlands.
"We are working with 130 or so cooperators around the state who over the last several years have produced a million and a half beetles that have been placed in at least 250 new areas with loosestrife infestations," says Brock Woods, research ecologist at the Wisconsin Department of Natural Resources. "This has captured the imaginations of the volunteers, and the media as well. It's been a very popular project in Wisconsin."
Purple loosestrife is an aggressive, nonnative weed that is replacing native plants in wetlands because it has no natural enemies. In turn, wildlife that depend on the native plants for food are being driven out.
Woods says purple loosestrife has moved into almost every county in the state and occupies an estimated 40,000 acres of wetlands. "In the last couple of decades, the number and size and density of loosestrife infestations have all increased, despite increasing traditional control efforts to try to curb it."
To combat the rapidly spreading weed, state researchers turned to biological control, and beetles and weevils were imported from Northern Europe to eat the plants. After exhaustive testing at Cornell University to be sure they would be safe, the insects were released at two Wisconsin sites in 1994.
"The beetles were very successful in a much shorter time than expected," Woods explains. "Within two to four seasons, they were reducing the amount of flowering and seed production by 90 percent on sites two acres or less. Curtailing the flower and seed production eliminates the plant's ability to keep spreading, which is a huge step toward controlling it."
While the results of the release proved encouraging, and monitoring of the sites found no problems, state funding for the program remained minimal, Woods says. "I decided the only way we could get a lot of beetles out quickly was to get more help. I went to the public and started asking lake associations, school teachers, conservation organizations, and private industries if they would be interested in rearing some of these beetles, and paying the costs of doing it themselves."
Woods notes that the program is relatively cheap, costing volunteers about $200 to take 100 beetles in May and release the resulting 10,000 beetles in July or August. "This project is so easy, and volunteers are so concerned about their local wetlands, that many people came forward who were willing to continue the program and provide the necessary funds themselves. That made the whole thing take off quickly."
He adds, "The opportunity for educators is perhaps the real silver lining in the loosestrife cloud. There are many great curricular activities that can be centered on this work."
"I feel good about it," Woods says. "As time goes by, I feel better and better. It's probably biologically impossible to eliminate the species. We just need to tame it a bit. Sometimes it's better to work with nature and not try to get it to do everything we want."
For more information about the Purple Loosestrife Biocontrol Project, point your Web browser to www.dnr.state.wi.us/org/land/er/invasive/info/loose2.htm or www.nysaes.cornell.edu/ent/biocontrol/weedfeeders/galerucella.html. You may also contact Brock Woods at (608) 221-6349, or woodsb@dnr.state.wi.us.
