Rachel Cliche, 6/14/2006, Garrett Island, "mile-a-minute invading Island habitats."

Katie Silcox, 6/14/2006, Garrett Island, "Approximately, 400 Asian Weevils released to biologically manage mile-a-minute."

Katie Silcox, 6/14/2006, Garrett Island, "R. latipes beetles feeding on mile-a-minute."

Biologist, Rachel Cliché opens the lid of the shipment container to release approximately 400 Asian Weevils (Rhinoncomimus latipes Korotyev) into an extensive tangle of mile-a-minute weed (Polygonum perfoliatum L.). These stem-boring weevils, about 2mm long, are being used as part of a biological control program targeting mile-a-minute weed on Garrett Island, a division of the Chesapeake Island National Wildlife Refuge in Maryland. 

Mile-a-minute is an annual Asian vine that grows rapidly, climbing over other plants, and attains lengths of 6 meters or more.  It invades a variety of habitats in the northeastern, United States, including forested floodplains, streamside herbaceous wetlands and upland forests.  The biological program for mile-a-minute was initiated by the Forest Service in 1996, and was approved for field release in July 2004.

The refuge received funding for monitoring the program from the University of Delaware, and it received R. latipes beetles from the Phillip Alampi Beneficial Insect Lab.  The beetles were released on June 14, in conjunction with a field trip for the Friends of Blackwater National Wildlife Refuge.  This trip not only introduced the Friends to the Chesapeake Island Refuges, but also provided an educational opportunity on the damaging effects of invasive species on native habitats and refuge management techniques.   

Two interns were hired to monitor this site following the release of the 2006 “Mile-a-minute Weed Monitoring Protocol” put together by Judy Hough-Goldstein, Professor of entomology and wildlife ecology at the University of Delaware. 

Interns Katie Crane and Katie Silcox set up 15 monitoring quadrants in a release and control site on Garrett Island.  Once a month, they assess the percent of defoliation caused by the weevils and the presence of node damage, indicating emergence of the weevil larvae.  Biweekly, the interns monitor the seed production of mile-a-minute by noting the presence of mature and immature fruit in a 10 by 1 meter plot at both sites. Signs were posted at each of the sites to educate people about the project and asking visitors not to disturb the area. 

The biological control project is an excellent example of agencies collaborating to manage an invasive species.  The Asian weevils are one management technique the Chesapeake Island Refuges staff is utilizing to control the mile-a-minute invasion plaguing Island habitats.