enlarge
Gordon Chibroski/Staff Photographer
enlarge
Gordon Chibroski/Staff Photographer
"The darn greenheads are so annoying," said Janine Durant, visiting the town-owned beach with her daughter and twin granddaughters. "We've lived in Scarborough all our lives, and I've never seen them so terrible."
Durant and her daughter, Jacqueline Durant-Harthorne, estimated that in a morning at the beach they'd killed about 50 greenhead flies -- fast-moving pests with bright green heads that deliver painful bites. One fly still managed to nip one of the twins, who are not quite 2 years old, making her cry.
It's the time of year when greenhead flies, which breed in marshes along the coast, frequent beaches along with sunbathers. And it appears that a greater number of the persistent pests may be around this year.
Charlene Donahue, an entomologist with the Maine Forest Service, said that while she doesn't have any data on greenheads, she's heard reports that deerflies -- close cousins of the greenhead fly -- are present in greater numbers. She said no one can be sure, however, because the state doesn't have the resources to keep track of the numbers of insects that don't carry diseases that threaten people's health or hurt the state's economy by destroying trees.
What is certain is that we're in the heart of the season for deerflies and greenheads, as well as their other annoying relatives such as horseflies, and a bite by even one or two of the hard-to-kill insects can be a spoiler for people trying to enjoy the outdoors.
Just down Ferry Beach, Cate Baker was sunning with three friends. She said the greenheads seemed to have a particular affinity for her. "I've killed three and I've had three bites," said Baker, a 22-year-old visiting from Australia.
Her friend, Jess Morgan, also 22, said that in Australia they're called "March flies," the local name for horseflies.
Donahue said horseflies, greenhead flies and deerflies are related. She said they even have a cousin called a "moose fly," although those are more common in northern Maine. "If you know what a deerfly is, a moose fly is probably four times that size," she said.
She said the flies are all classified as Tabanidae, a family of large, blood-sucking flies. There are many types, Donahue said. She said 76 species of tabanids have been identified in Maine and there may be even more. "Not all of them bite people," she said.
What they do have in common is similar life cycles, Donahue said. For example, only the female bites and that's because she needs a protein blood meal to produce her eggs, she said.
And the insects, which are swift and agile, also all have blade- like mouth parts instead of needle-like organs that biting insects like mosquitoes have. "They have mouth parts that tear into your skin and then they lap up the blood," Donahue said.
She said that after the adults mate, the eggs are laid on vegetation near water and the larvae live in or near the water.
If there are more greenheads and deer flies this year, Donahue said there aren't any obvious reasons why. Although the summer has had periods of wet and dry, cold and heat, none has been long enough to make significant differences in the population, she said. One possibility, she said, is that weather conditions have "compressed" the insects' season, enabling a lot of them to mature all at once, instead of more gradually over a period of weeks.
Whatever the reason, Ferry Beach in Scarborough seems to be especially hard hit. Steven Crups, 17, who sits all day at a booth at the park collecting entrance fees, said the flies like to join him on the job. "It seems like there's a lot more than last year," he said.
At Wolfe's Neck Woods State Park in Freeport, manager Andy Hutchinson believes there may be a few more greenheads and deerflies than usual, although he said typically...
Reader comments
Click here to view or add comments on this story
Were you interviewed for this story? If so, please fill out our accuracy form