If you are heading outdoors ticks are just one of the pests you need to watch out for this summer. Credit: Linda Coan O'Kresik / BDN

This story was originally published in June 2021.

Browntail moth caterpillars and an abundance of dog ticks have made late spring pretty tough here in Maine. But these pests aren’t the only ones to expect this summer.

While you can’t completely avoid any of these pests outside, knowing what you are up against can help you limit your exposure. That knowledge can also help you treat any bites, rashes or other allergic reactions they may cause.

From those that are a mere nuisance to those causing potential health issues, here are six pests to be on the lookout for this summer.

Browntail moth caterpillars

Browntail moth caterpillars, like those seen here, are coming from the trees and bringing with them health risks, according to the Maine Centers for Disease Control. Credit: Courtesy of Maine CDC

Last summer was the worst for the invasive browntail moth caterpillar since it first arrived in Maine a century ago.

With browntail moth activity in all 16 Maine counties, many people around the state are experiencing the blistery rash similar to poison ivy or respiratory distress caused by the caterpillars’ poisonous hairs.

Fortunately, most allergic reactions can be treated with over the counter remedies. Pharmacies in Maine can also prepare doctor-prescribed compounds for more serious reactions.


Ticks are on the move in Maine, especially dog ticks which have been reported in numbers far exceeding last year’s count. A dog tick, right, is twice the size of the Lyme disease-carrying deer tick seen on the left. Credit: Courtesy of Griffin Dill

Recent dry conditions and winters helped lead to an explosion in the dog tick population in Maine. Dog ticks are considered a nuisance pest that cause reactions ranging from minor itching to some localized pain, according to experts at the University of Maine.

That is very different from the seriousness of a bite from another tick found in Maine — the Lyme disease-carrying deer tick.

To protect yourself when venturing outside, experts recommend using an insect repellent that includes DEET, wearing long pants tucked into your socks and long sleeved-shirts with tight cuffs or clothes that have been treated with permethrin. Some people are also using a trick with duct tape to trap ticks before they get a chance to bite. Every foray outside should be followed by an all-body tick check when you get back inside.

Black flies

An adult black fly feeding on a human. Credit: Courtesy Griffin Dill

Anyone who has spent any time outside in the Maine woods during the summer has no doubt experienced clouds of tiny winged black flies. The state is home to 48 different species of this biting pest that has been jokingly referred to as the Maine State Bird.

Reactions to black fly bites range from an annoying itchy bump to more serious reactions including swollen lymph nodes and respiratory issues. Black flies’ life cycle requires running water so they are often found close to streams and rivers. They are active feeding and biting during the day.

To avoid becoming a moving black fly feast, you can use chemical insect repellents and wear light-colored clothing that does not seem to attract the flies like darker shades.


An adult mosquito prepares to feed on a human. Credit: Courtesy of Griffin Dill

It can appear that the biting insects in Maine work in shifts. That’s because when the black flies become inactive at night, mosquitos take their place. Of the more than 40 mosquito species in Maine, about half feed on human blood.

Mosquitos are most active at dusk and dawn when temperatures are above 50 degrees Fahrenheit. They are a nuisance when they swarm around you and can leave you with an itchy welt when they bite. But they are also a serious health threat as carriers of Eastern Equine Encephalitis and West Nile virus.

Wearing long sleeve shirts and pants and using an insect repellant can help cut down on exposure.

Deer flies

Deer flies are the largest, fastest and among the nastiest of flying pests in Maine. Credit: Courtesy of Griffin Dill

When it comes to flying pests, few are as large or as dreaded by outdoors enthusiasts as the deer fly. Also known as the moose fly, these biting insects can be up to an inch and a half long.

Deer flies use their scissor-like mouthparts to slash into your skin so they can lap up your blood. The bite is painful, and leaves a large, itchy welt. They are among the fastest of all flying insects, so don’t even try to outrun them. That just seems to annoy a deer fly which will simply follow you, while circling around and bouncing off your head.

These flies are sight-hunters, attracted by motion so insect repellents — which rely on scent — have no effect. They are attracted to dark colors, so avoiding dark clothing is recommended. There is a bit of good news — deer fly larvae feed on mosquito larvae, so there is that.


Fine mesh netting over window screens or in tents is one of the only ways to avoid tiny biting midges. Credit: Julia Bayly / BDN

Biting midges in Maine are commonly referred to as no-see-ums due to their tiny size. They are so small they can easily fly through most window screens. You may not even notice them until you feel a tiny pin-prick like bite on your skin.

Fortunately, that brief discomfort is typically the only reaction associated with a midge bite, but if enough of them are around, it can be extremely annoying. They are most active and feed around dusk.

Chemical insect repellants have little effect on biting midges. Instead, you can keep them from getting inside by covering your window screens with fine-mesh netting. Other than that, scheduling your outdoor activities to avoid peak no-see-um hours is the most effective way to avoid getting bitten.

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Julia Bayly

Julia Bayly is a reporter at the Bangor Daily News with a regular bi-weekly column. Julia has been a freelance travel writer/photographer since 2000.