Weevils continue battling invasive vines
Updated 11:30 pm, Wednesday, August 29, 2012
Researchers this week found mixed results in Greenwich in the effort to control an invasive vine.
University of Connecticut researchers and Connecticut Agricultural Experiment Station scientists, along with a town official and an Audubon Greenwich employee, on Tuesday visited Audubon Greenwich's Gimbel Sanctuary off Sherwood Avenue and Bruce Park, two areas where weevils, a kind of beetle, had been released to combat the mile-a-minute vine.
Aleksandra Moch, a town wetlands analyst, was impressed with the weevils' work in a Bruce Park area where weevils were released in 2011.
"It looks like it is under control and in some sort of balance with other plants," she said after a count of weevils at the site. "It looks like it is working."
Spread out over the area, researchers counted weevils in a five-minute span.
The weevils eat through the plants, resulting in leaves looking like Swiss cheese.
A surprise awaited the group at its second stop, the Gimbel Sanctuary.
The scientists had last been there in June. In the meantime, the Audubon cut down a pair of locust trees in the area where weevils were first released in 2009. Also, another area where weevils were released about 20 yards away had also been cleared.
Audubon Greenwich's Andrew Chapin said the trees were cut and the area was cleared to prevent trees from growing because the Audubon wants it to remain a meadow.
While it resulted in fewer weevils, Donna Ellis said she is confident the weevils would move to other areas to seek out mile-a-minute plants, which can choke off native plant life.
"The damage is coming along here. We would like to see more of what it is like in Bruce Park, but certainly there are holes in the leaves," said Ellis, co-chair of the Invasive Plant Working Group.
Weevils reproduce quickly, with a new batch of adults emerging about every four weeks, she said.
Scientists believe the vine arrived in a delivery of holly seeds from Japan to a now-defunct nursery outside of York, Pa., in the 1930s. The vine seeds may have been spread by birds or inadvertently by humans. The vines gradually spread outward from Pennsylvania into other mid-Atlantic states.
Scientists turned to weevils as a way of naturally controlling the rapid spreading vines.
The weevil -- no larger than an eighth of an inch -- eats the vine, slowing its growth. That helps prevent the vine from overpowering native plants.
In Greenwich, the mile-a-minute vine was first spotted along King Street and Sherwood Avenue in 2000. Many of the plants took root in the 80-acre Gimbel Sanctuary.
Beginning in 2009, weevils have been released in a number of locations throughout the state, including Greenwich. The researchers have conducted counts throughout the state in the last week, also visiting Wilton, Norwalk and Fairfield.