Researchers Release New Bio Agent to Fight Invasive Weed
Date:10-07-2013
University of Rhode Island entomologists reached a milestone in their efforts to control the invasive weed swallow-wort this month with the first release of a biological agent to fight the pest.The URI scientists, led by Professor Richard Casagrande and Research Associate Lisa Tewksbury, sent 500 larvae of the moth Hypena opulenta to partners in Canada for release in patches of swallow-wort near Ottawa.
"Swallow-wort is an aggressive invasive perennial weed that forms dense patches in a wide variety of habitats and may have negative impacts on monarch butterfly populations," said Casagrande. "But we believe that this moth has potential for keeping the weed in check.In 2006, URI doctoral student Aaron Weed discovered the moth larvae feeding on swallow-worts in southern Ukraine."
He brought the larvae to partners at the Commonwealth Agricultural Bureau International (CABI) in Switzerland for rearing and initial testing. Research on the biology, impact, and host range of these insects was conducted at CABI and in the URI Insect Quarantine Laboratory over the next six years by Weed, now a postdoctoral researcher at Dartmouth College, and a second URI graduate student, Alex Hazlehurst.
After finding that the moth larvae will only attack and survive on swallow-worts, the URI scientists and colleagues in Canada and Switzerland petitioned the U.S. Department of Agriculture in 2012 to allow field release of this biological agent in North America. The review panel recommended it for USDA approval on September 4.
The USDA has additional steps in its approval process before the agent can be released in the United States next spring, but the Canadian government granted permission for immediate release.The URI team sent larvae to partners at Canada Agriculture late last week for the first release. According to Naomi Cappuccino of Carleton University, the release appeared successful and larvae were already pupating in preparation for the Canadian winter.
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