Mosquitoes, those pesky bloodsuckers that put a damper on summer barbecues and camping trips, have long been a problem for some Maine communities.

Insect-slaying pesticides fell out of favor decades ago, but there is a mosquito control option that at first blush seems like the perfect alternative: dragonflies.

Some municipalities and business groups sell dragonfly nymphs in the spring directly to anyone who wishes to set them free.

The catch? If the dragonflies are coming from out of state, the practice is illegal.

Phillip deMaynadier, a wildlife biologist with the Maine Department of Inland Fisheries and Wildlife, said any introductions of non-native species into Maine from another state require a permit. It doesn’t matter if it’s a giraffe or a cockroach – the department wants to know about it. It’s not that there is an acute risk with importing new species; it’s just the effects are rarely studied before it’s far too late.

However, few of the nymph sellers actually apply for a permit. Any individual or business that knowingly imports or possesses a restricted exotic species is subject to a fine of $50 for each day the individual or business is in violation.

DeMaynadier acknowledged that the state has been less focused on enforcement and more on making people aware of the permitting process. He said non-permitted dragonflies are among the most common offenses.

The Wells Chamber of Commerce has been ordering dragonfly nymphs from a private dealer for more than 35 years, said Executive Director Eleanor Vadenais. This year, more than 13,000 nymphs were sold.

“Our dragonfly program has been a great success, otherwise we probably wouldn’t continue to do it,” she said.

The Wells program works like this: The chamber sends out applications to residents or businesses that want to purchase a group of dragonfly nymphs. Once the orders are taken, the chamber arranges to have the insects delivered in two shipments to be picked up by the person or business that ordered it.

The town of Scarborough, much of which is located in marshy areas, also buys dragonflies in bulk for resale. This year, 2,500 groups of insects were sold, said Steve Kramer, a scheduler in the town’s community services department.

Gail Atkins, a property manager with Portland-based Dirigo Management Co., purchased dragonfly larvae from the town of Scarborough last year on behalf of Cider Hill Village, a 173-unit condominium complex she manages in Old Orchard Beach.

“The feedback among the condo association members was great. They said there were no mosquitoes and they enjoyed having the dragonflies around,” Atkins said. “Who doesn’t love dragonflies?”

Atkins said she would like to use dragonflies at other properties she manages, but the conditions have to be right.

“You really need standing water for the dragonflies to prosper,” she said.

Even though the dragonflies appear to be a hit, neither the Wells chamber nor the town of Scarborough has requested a permit through the state. Scarborough purchases its dragonflies from Berkshire Biological, a Massachusetts company, Kramer said. Representatives of that company did not return calls for comment about what species it sends to Maine or how often it gets requests.

Vadenais would not say where the Wells Chamber of Commerce gets its nymphs. DeMaynadier said he’s spoken with officials at the Wells chamber who told him they get their larvae from a commercial biological supply company. He knows of no such supplier in Maine.

Even if residents didn’t buy from the town of Scarborough or the Wells chamber, there is nothing to stop someone from online purchases.

DeMaynadier said that’s a problem. There are more than 150 dragonfly and damselfly species present in Maine, but more than 450 species nationwide. He said that’s why people are supposed to get permits from the state, because otherwise it’s not possible to tell whether any of the species being brought in are native to Maine.

Alysa Remsburg, an ecologist at Unity College whose research includes dragonflies and damselflies, agreed with the state biologist that importing new species into Maine could be a problem, but said she doesn’t know if the actual impact of bringing in non-native dragonflies has been studied.

A permit is also required for the commercial collection of any species, meaning anyone who is collecting or breeding dragonflies for sale would need approval from the state. DeMaynadier said he is not aware of any state permits granted for insect collection.

Both deMaynadier and Remsburg questioned the efficacy of using dragonflies to control mosquitoes.

“We know dragonflies are voracious predators, but they will eat any kind of insect, usually whatever is most abundant,” Remsburg said. “I don’t know of any documented studies that says they are an effective control.”

She said dragonflies undoubtedly help with mosquito control, but they are “not the silver bullet.”

DeMaynadier said an influx of dragonflies in some areas could increase the competition and predation of other aquatic organisms. In some cases, that could lead to further endangerment of some insect species.

There also is no guarantee that transplanted dragonflies will adapt to a new ecosystem, he said.

The best option for handling mosquitoes, deMaynadier said, is to either use repellents to keep them at bay or just accept them as a part of life here.

“Learning to accept mosquitoes as an important, albeit annoying, component of our natural ecosystems is, hands down, the least risky alternative of all,” he said.

Eric Russell can be contacted at 791-6344 or at:

erussell@pressherald.com

Twitter: @PPHEricRussell