SALISBURY/LEICESTER — The Lake Dunmore/Fern Lake Association (LDFLA) wants to enlist the help of some tiny insects to accomplish a feat that has thus far eluded hail divers and heavy marine equipment: the eradication of Eurasian milfoil.
The LDFLA has applied for permission from the Vermont Agency of Natural Resources to introduce thousands of Euhrychiopsis lecontei — aka milfoil weevils — as another weapon in removing the nuisance aquatic weeds that have been steadily encroaching on the lakes.
If permitted, the weevils would be unleashed to munch on milfoil in a handful of select, shallow areas where there would be little recreational activity to disrupt them. Suction harvesting, with the aid of divers, would continue in deeper areas with dense milfoil growth.
“I think this will be another tool for us; it is not a cure-all,” stressed association President Sue Potter. “We are trying to keep up with (the solutions) that might be available to us.”
Eurasian milfoil was first found in Lake Dunmore in 1988. It’s presence increased to the point where lakefront property owners formed an association in 1994 to combat the pesky plant, which can overwhelm bodies of water and put a serious damper on recreation.
The association eventually hired some college students on a seasonal basis to conduct dives and pull the plants, which are then fed into a suction harvester and removed to the shore. Milfoil spreads if it is chopped and left to re-sew into the bed of a lake.
But in spite of the LDFLA’s best efforts (which are partly underwritten by Salisbury and Leicester taxpayers), milfoil continues to make further incursions into the lakes.
Divers harvested well over 1,000 bushels of milfoil in 2011, which was more than double the previous year’s tally.
“Both lakes are seeing significant spread of milfoil, which requires multiple days or weeks working on specific patches,” reads an October 2011 update on the LDFLA website. “During these periods of time, we are seeing significant re-growth in areas previously harvested, putting us back to square one in many of the patches.”
This spurred the LDFLA to reach out to Middlebury College Professor of Biology Sallie Sheldon, whose work with the milfoil-eating aquatic weevils had earned her national acclaim. While Sheldon’s weevil work essentially ended in 1995, she made a brief comeback in 2006 and 2007. She has again decided to come out of retirement, in deference to the plight of the lakes and because she believes the LDFLA has acted responsibly through the years in its milfoil management plan.
If the LDFLA gets its permit, Sheldon and her helpers will look for, and gather, thousands of weevils.
“They can be extraordinarily difficult to find,” said Sheldon, though she has a general idea where to scout for the insects, which are around half the size of a grain of rice.
Plans call for the weevils to be inserted into a handful of shallows in the lakes this summer. Sheldon said the weevils can have a “substantial” impact on milfoil within three years of their introduction in a lake. She stressed that results are dependent on several factors, including weather events (like Tropical Storm Irene) and the extent to which lake activities thwart or kill the weevils. She noted that severing the weeds — by propeller or other means — often kills the weevils, as they live and eat on top of the plants. The application of chemicals can also hurt the weevil population.
She pointed to Glen Lake in Rutland County and Malletts Bay in the northeast corner of Lake Champlain as examples of bodies of water in which the weevils have substantially cut into milfoil growth because the bugs have been left alone.
Potter and other LDFLA members are hoping the weevils are on the way. There will be no shortage of food waiting for them.
“We can’t just sit back and rely on pulling the milfoil,” Potter said. “We won’t be able to keep up.”
Reporter John Flowers is at firstname.lastname@example.org.