This story was originally published in May 2023.
An insect that looks like a mosquito on steroids is one of the state’s more innocuous pests — unless you really love your coastal lawn.
Crane flies, which are see-through in larval form and have a really cool nickname, are one of the many invasive insects in Maine.
“For the most part they are not a huge problem here,” said Jim Dill, pest management specialist with University of Maine Cooperative Extension. “They live for the most part only two or three days and all they do is fly around, find a mate, mate and start their [lifecycle] all over again.”
It’s the larval stage of the European crane fly species that recently arrived in Maine that can be a problem, according to Dill.
“It showed up a few years ago on coastal islands and can be a fairly serious lawn pest,” Dill said. “They do lay some eggs in turf or grass and the larvae eat the foliage and roots.”
The crane fly is just the latest invasive species to cause problems for Mainers. In recent years, the state has seen increasing numbers of a variety of insects and other critters, including brown tail moths, dog ticks, emerald ash borers, hemlock woolly adelgid and more.
When enough crane fly larvae are feasting on lawns they can create brown and dead patches in the grass. They can also attract animals such as skunks, who will dig destructive holes in a yard looking for a meal of tasty grubs.
Damage from the larval activities has been observed on some of the islands and along Maine’s coast.
But for most of the state, crane flies are a minor annoyance on a summer’s night.
The adult fly’s body is almost an inch long with legs up to 4 inches long. The flies are attracted to light and can gather in large numbers flitting around like a cloud of giant mosquitos, but they do not bite or sting.
The larvae can be brown, green or white and some are even translucent, allowing you to easily see their internal organs moving around. They also have small tentacles that will extend if the larvae are disturbed.
The larvae do help with natural composting, as they also feed on decaying wood or other organic matter.
“They are also referred to as leatherjackets,” Dill said. “When they pupate in the summer they get a very tough skin that is a brownish color like tanned leather.”
The adult female crane fly lays her eggs late summer in moist, swampy areas or directly in water, according to Dill.
“They really don’t bother anyone,” Dill said. “For the most part, they are just out there.”
