Mile-a-minute vine, now found in most Fairfield County towns, has distinctive triangular leaves.

Mile-a-minute vine, now found in most Fairfield County towns, has distinctive triangular leaves.

Mile-a-minute vine, the fast-growing and rapidly spreading invasive plant now found in many Connecticut towns, continues to move throughout the state.  Fortunately, a tiny beneficial insect that feeds on this invasive vine is also following closely behind.

This year, new populations of mile-a-minute were found in Groton, Madison, Middlefield, Milford, Old Saybrook, Prospect, and Stratford for the first time.

Additional spread of the vines occurred within many of the 24 towns where mile-a-minute had previously been confirmed — including Ridgefield, Wilton, Redding, and Danbury.

An adult weevil

An adult weevil

Scientists at the University of Connecticut (UConn), the Department of Energy and Environmental Protection (DEEP), and the Connecticut Agricultural Experiment Station (CAES) are continuing efforts to control the plant, which outcompetes native species.

Mile-a-minute is an annual vine that spreads by seed and quickly grows into dense stands that can cover and shade out native vegetation.

Scientists from UConn and CAES are conducting a biological control study in the state and have released a beneficial insect at a number of sites since 2009.The insect, a tiny (2 mm) stem-boring weevil, was closely studied under quarantine conditions prior to release in the United States, where it was found to feed and reproduce exclusively on mile-a-minute vine.  The insects are expected to help reduce populations of this invasive plant over time.  At several locations where new mile-a-minute populations were confirmed, weevils were observed already feeding on the vines.

“It is encouraging to see that these beneficial insects are spreading on their own to help reduce the amount of mile-a-minute present in our landscape.  The insects are very good at locating small patches of this invasive plant and can fly from an area where they are established to a new site, where they begin feeding on the vines”, says Donna Ellis, Senior Extension Educator at UConn and project coordinator for the state biological control program.

“This is a great time of year to get outside, and it is also the best time of year to look for mile-a-minute vine, since these annual plants are at their largest later in the season.  If you find a plant you think might be mile-a-minute, please let us know about it before pulling it up or throwing it away”, says CT Invasive Plant Coordinator Logan Senack.  “We may need to collect more information about the plant, confirm that it is mile-a-minute and not a similar species, and look for the beneficial insects at the site before the plants are removed.”

Recently released weevils eating a leaf.

Recently released weevils eating a leaf.

Photos and additional information about mile-a-minute and the biological control agents are available at www.cipwg.uconn.edu (follow link under “Focus Species” on right of page).

 To report a suspected mile-a-minute invasion, visit the CIPWG website (www.cipwg.uconn.edu), email mileaminute@uconn.edu, or contact Donna Ellis at UConn  (860-486-6448).The Connecticut Invasive Plant Working Group will host a full-day symposium about invasive plants at the University of Connecticut in Storrs on October 25, 2012.  Information about the symposium is available online atwww.cipwg.uconn.edu.