Fighting one exotic species with another

Purple loosestrife is target of beetles

Pretty purple plague, meet the beetles.

A number of residents in this region are preparing to raise thousands of imported beetles in a campaign to rid local wetlands of purple loosestrife, a fast-growing and hardy invasive plant that specialists say crowds out New England natives, like cattails, and can clog small ponds to the point of ruining them for skating in the winter.

The plan, hatched by state environmental officials, is to organize beetle growers through local nonprofits like the Groton-based Nashua River Watershed Association and Squannassit-Petapawag Stewardship Committee, whose guides are expected to make sure the beetles - called galerucella - are released into the wild properly. Then everyone can sit back and watch as the beetles chomp away at their favorite food.

"Does anyone have questions involving being a beetle farmer or wrangler?" Beth Suedmeyer, restoration planner for the Massachusetts Office of Coastal Zone Management, asked during a recent beetle-raising workshop at the Nashua River Watershed Association's headquarters in Groton.

Suedmeyer, whose agency oversees the state's purple loosestrife eradication program, showed how would-be beetle farmers need to dig up and pot a ball of purple loosestrife roots in mid- to late April, wait until the roots grow stems 18 inches tall, place beetles on the stems in May, then wait until the beetles mate and produce offspring in August. Growers cover their plants with screen meshes to trap the beetles. Once the mesh is teeming with galerucella, they are released in wetlands designated by the state.

The US Department of Agriculture approved releasing beetles in 1992 after six years of studies examining whether they would cause more problems than they would solve, according to the state's Coastal Zone Management website.

Workshop attendants, including Nashua resident Merle Insinga, nodded their heads as Suedmeyer explained the cultivation process. Insinga knows purple loosestrife well and isn't fooled by its beauty. She has seen the plant practically fill a reservoir in her native Pennsylvania.

"It astounded me how rapidly it had taken over," she said after the workshop, adding that she did not intend to have it do the same in her adopted city. "Certainly around Nashua, almost every wetland and drainage area around town has an ample population of purple loosestrife."

Insinga believes she is a perfect foot soldier in the war against the plant, having raised many critters with her son, Jonas, a zoology major at the University of New Hampshire. Insects need only food, water, and the right temperature, she said. They aren't complicated like fish and do not need tender loving care like dogs or rabbits. What's more, they are natural. She wanted no part in bombing riverbanks, swamps, and streams with herbicides and other toxins, she said.

"I've had experience growing bugs. Mostly I've raised meal worms for his leopard geckos and tree frog," she said. "I feel a great deal of adversity comes from trying to control things chemically." The chemicals "don't decay as rapidly as I'd like."

Able to grow more than 8 feet tall, purple loosestrife came to the United States from Europe and Asia in the early 1800s in the soil that was used as ballast in ships' hulls, said Suedmeyer. Because it is arguably beautiful in full bloom, and because it helps bees produce good honey, settlers encouraged its growth.

Now, however, the plant is threatening to overwhelm local ponds, riverbanks, and swamps, especially in northern Massachusetts, Suedmeyer said. Because of its extensive root network, it grows back if it is cut down, and its tiny seeds, around 2 million on a mature plant, are easily scattered.

Once it takes over, she said, the invader kills off other wetland plants that provide food and shelter to native birds and other animals. It also changes the chemical composition of the water where it grows. Studies show that frogs reproduce less successfully where it dominates, said Suedmeyer.

But purple loosestrife has an archenemy: the light-brown, 4-millimeter-long galerucella beetle, whose diet consists solely of the plant. Loose them on the loosestrife, said Suedmeyer, and in a couple of seasons the plants' leaves will be brown and filled with holes.

The beetles, also originally from Europe and Asia, do not eat purple loosestrife's roots, so they do not necessarily kill it off entirely. But they are one of the better ways to control the plants, Suedmeyer said.

She said Massachusetts has released 300,000 beetles since 2000; Granite State environmental officials have also released hundreds of thousands of beetles, according to the website of the New Hampshire Department of Transportation, which maintains a beetle program. Because the galerucella is nonnative, authorities want to monitor where and how the beetles are used.

Suedmeyer said she will provide as many interested residents as possible with about 20 beetles per plant to start their own hordes. In exchange for the beetles, however, growers need to agree to keep in contact with the NWRA, whose officers will monitor their progress and organize where they should be set free.

Officials are considering deploying beetles in Ayer, Groton, Lunenburg, and Pepperell. They are securing permission from local property owners and conservation commissions, who oversee local wetlands and usually allow the beetles to be released, Suedmeyer said. After a year or two of releasing beetles in the same area, it is not uncommon to find around 1,000 beetles on one plant, she said.

Suedmeyer was not surprised that as many as 60 people attended the March 31 workshop. People are craving hands-on experiences that put them in touch with nature's life cycles, and they are sick of the dangers of herbicides, she said. "This seems to be something that really hit a nerve in the community," she said.

Workshop attendant William Daniels, chairman of Ayer's Conservation Commission, said he would try anything to rid the wetlands on his property of the loosestrife. "In the beginning, we started to see purple come up," he said. "My wife thought it was pretty, and she's right."

But now, said Daniels, he is afraid the purple pandemic is going to consume his backyard. "If you're standing in a 10-foot area, there's got to be 20 plants," he said. "The density is pretty remarkable."

Residents interested in participating in the NWRA and state beetle program should call Rick Muehlke at 978-448-0299. Those who want to acquire beetles on their own need to go through an application process with the US Agriculture Department and pay around 11 cents per beetle, according to Suedmeyer.

John Dyer can be reached at johnjdyerjr@gmail.com.

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