Maine’s dense forests and numerous lakes create ideal breeding grounds for mosquitoes, black flies, and midges. When you step outside in the Pine Tree State, you quickly realize there are many Types Of Flies In Maine that can ruin your day. Understanding these insects helps you prepare and enjoy the outdoors more.
Black flies are the most notorious pests here. They swarm in late spring and early summer, especially near rivers and streams. Their bites can cause itching, swelling, and even allergic reactions in some people.
Mosquitoes are another common nuisance. They breed in standing water and are active from dusk to dawn. Maine has over 40 species of mosquitoes, each with its own habits.
Deer flies and horse flies are larger and more aggressive. They attack during the day and their bites are painful. You’ll find them near wooded areas and wetlands.
Stable flies look like house flies but bite. They often target livestock and pets, but they will bite humans too. Their bites are sharp and can cause welts.
Types Of Flies In Maine
Maine has a wide variety of flies, from tiny midges to large horse flies. Knowing the differences helps you identify them and choose the right repellent. Below is a breakdown of the most common types you will encounter.
Black Flies (Simuliidae)
Black flies are small, humpbacked insects that breed in fast-moving water. They are most active in May and June. Their bites can cause severe itching and swelling.
- Size: 1/16 to 1/8 inch
- Color: Dark gray to black
- Breeding: Streams and rivers
- Active: Dawn and dusk
- Repellent: DEET or picaridin
These flies are known for swarming around the head and face. They can crawl into your ears, nose, and eyes. Wearing a hat with a net is the best defense.
Mosquitoes (Culicidae)
Maine has many mosquito species. Some carry diseases like West Nile virus and Eastern Equine Encephalitis. Most are active from spring through fall.
- Size: 1/8 to 1/2 inch
- Color: Brown, gray, or black
- Breeding: Standing water
- Active: Dusk to dawn
- Repellent: DEET, picaridin, or oil of lemon eucalyptus
Mosquitoes are most common near marshes, ponds, and lakes. They are also found in suburban yards with bird baths or clogged gutters. Removing standing water reduces their numbers.
Deer Flies (Chrysops)
Deer flies are medium-sized with patterned wings. They are aggressive biters and prefer warm, sunny days. Their bites are painful and can cause allergic reactions.
- Size: 1/4 to 1/2 inch
- Color: Yellow and black stripes
- Breeding: Wetlands and marshes
- Active: Daytime
- Repellent: DEET or permethrin-treated clothing
Deer flies are most active in July and August. They are attracted to movement and dark colors. Wearing light-colored clothing helps reduce attacks.
Horse Flies (Tabanus)
Horse flies are large and robust. They have large eyes and powerful mouthparts. Their bites are deep and painful, often drawing blood.
- Size: 1/2 to 1 inch
- Color: Dark brown or black
- Breeding: Moist soil near water
- Active: Daytime
- Repellent: DEET or physical barriers
Horse flies are strong fliers and can chase you for long distances. They are most common near farms and pastures. Traps can help reduce their numbers.
Stable Flies (Stomoxys Calcitrans)
Stable flies look like house flies but have a pointed mouthpart for biting. They are common around livestock and pets. Their bites are sharp and can cause welts.
- Size: 1/4 inch
- Color: Gray with dark stripes
- Breeding: Decaying organic matter
- Active: Daytime
- Repellent: DEET or fly sprays
Stable flies are most active in summer. They often bite the legs and ankles. Keeping barns clean and using fly traps helps control them.
Midges (Chironomidae)
Midges are small, non-biting flies that look like mosquitoes. They swarm in large numbers near water. They do not bite but can be annoying.
- Size: 1/8 inch
- Color: Green, brown, or black
- Breeding: Lakes and ponds
- Active: Evening
- Repellent: Not needed
Midges are often called “lake flies” because they emerge from lakes in huge swarms. They are harmless but can cover surfaces and get into your eyes and mouth.
House Flies (Musca Domestica)
House flies are common indoors and outdoors. They do not bite but can spread diseases. They are attracted to food and garbage.
- Size: 1/4 inch
- Color: Gray with four dark stripes
- Breeding: Decaying organic matter
- Active: Daytime
- Repellent: Sanitation and screens
House flies are most common in summer. They can carry bacteria like E. coli and Salmonella. Keeping food covered and disposing of trash properly reduces their presence.
Fruit Flies (Drosophila)
Fruit flies are tiny and attracted to ripe or rotting fruit. They are common in kitchens and gardens. They do not bite but can be a nuisance.
- Size: 1/8 inch
- Color: Tan with red eyes
- Breeding: Fermenting fruit
- Active: Daytime
- Repellent: Remove fruit sources
Fruit flies are most common in late summer and fall. They can be controlled by storing fruit in the refrigerator and cleaning up spills.
Cluster Flies (Pollenia)
Cluster flies are larger than house flies and have a golden sheen. They enter homes in fall to overwinter. They do not bite but can be annoying.
- Size: 1/4 to 3/8 inch
- Color: Dark gray with golden hairs
- Breeding: Earthworms
- Active: Fall and spring
- Repellent: Seal cracks and gaps
Cluster flies are most common in rural areas. They often gather in attics and wall voids. Vacuuming them up is the easiest way to remove them.
Green Bottle Flies (Lucilia)
Green bottle flies are metallic green or copper. They are attracted to dead animals and garbage. They do not bite but can spread diseases.
- Size: 1/4 to 1/2 inch
- Color: Metallic green or copper
- Breeding: Carrion and garbage
- Active: Daytime
- Repellent: Sanitation
Green bottle flies are most common in summer. They are often seen around trash cans and compost piles. Keeping these areas clean reduces their numbers.
Flesh Flies (Sarcophagidae)
Flesh flies are medium-sized with gray and black stripes. They are attracted to decaying meat and animal waste. They do not bite but can be a sign of poor sanitation.
- Size: 1/4 to 1/2 inch
- Color: Gray with black stripes
- Breeding: Carrion and feces
- Active: Daytime
- Repellent: Sanitation
Flesh flies are most common in rural areas with livestock. They can be controlled by removing animal waste and keeping areas clean.
Robber Flies (Asilidae)
Robber flies are predators that catch other insects. They are large and have a long, pointed proboscis. They can bite if handled but are not aggressive.
- Size: 1/2 to 1 inch
- Color: Brown, black, or yellow
- Breeding: Soil and wood
- Active: Daytime
- Repellent: Not needed
Robber flies are beneficial because they eat pests like mosquitoes and deer flies. They are most common in sunny areas with flowers.
Bee Flies (Bombyliidae)
Bee flies look like small bees with long, thin legs. They hover near flowers and feed on nectar. They do not bite or sting.
- Size: 1/4 to 1/2 inch
- Color: Brown, black, or yellow
- Breeding: Parasitic on other insects
- Active: Daytime
- Repellent: Not needed
Bee flies are most common in spring and summer. They are important pollinators. They are harmless to humans.
Dance Flies (Empididae)
Dance flies are small and often seen swarming in the air. They perform mating dances in groups. They do not bite humans.
- Size: 1/8 to 1/4 inch
- Color: Brown or black
- Breeding: Moist soil
- Active: Evening
- Repellent: Not needed
Dance flies are most common near streams and ponds. They are harmless and add to the biodiversity of Maine.
How To Identify Flies In Maine
Identifying flies can be tricky because many look similar. Here are some tips to help you tell them apart.
- Look at the size. Horse flies are large, while black flies are tiny.
- Check the wings. Deer flies have dark patterns, while house flies have clear wings.
- Observe the behavior. Biting flies are aggressive, while non-biting flies are more passive.
- Note the location. Black flies are near water, while fruit flies are near food.
- Use a magnifying glass to see details like eye color and body shape.
If you are unsure, take a photo and compare it to online guides. Many extension services offer identification help.
Prevention And Control Methods
Preventing fly bites is key to enjoying the outdoors. Here are some effective strategies.
Personal Protection
- Use EPA-approved repellents like DEET, picaridin, or oil of lemon eucalyptus.
- Wear long sleeves and pants in light colors.
- Use a hat with a bug net for heavy infestations.
- Avoid being outside during peak activity times.
- Use fans to keep flies away from patios and decks.
Environmental Control
- Remove standing water to reduce mosquito breeding.
- Keep grass and shrubs trimmed to reduce hiding spots.
- Use fly traps for deer flies and stable flies.
- Install screens on windows and doors.
- Keep garbage cans covered and clean.
Natural Repellents
- Citronella candles can help but are less effective than DEET.
- Essential oils like lavender, eucalyptus, and peppermint may repel some flies.
- Plant marigolds, basil, and lavender around your yard.
- Use garlic spray on clothing and skin.
When Are Flies Most Active In Maine?
Fly activity varies by season. Here is a general timeline.
- Spring (April-May): Black flies emerge first, followed by mosquitoes.
- Summer (June-August): Deer flies, horse flies, and stable flies are most active.
- Fall (September-October): Cluster flies enter homes, and mosquitoes decline.
- Winter (November-March): Most flies are inactive, but cluster flies may appear indoors.
Weather affects activity. Warm, humid days increase fly activity. Cool, dry days reduce it.
Health Risks From Fly Bites
Most fly bites cause minor itching and swelling. However, some can transmit diseases.
- Mosquitoes: West Nile virus, Eastern Equine Encephalitis, and Jamestown Canyon virus.
- Black flies: Can cause severe allergic reactions in some people.
- Deer flies: Can transmit tularemia (rare in Maine).
- Stable flies: Can cause painful welts and secondary infections.
If you develop a fever, headache, or rash after a bite, see a doctor. Most bites heal on their own with over-the-counter treatments.
Frequently Asked Questions
What is the most common fly in Maine?
The most common biting fly is the black fly. Non-biting house flies are also very common indoors.
How long do black flies last in Maine?
Black fly season typically lasts from mid-May to late June. Cool, wet weather can extend the season.
Are there any dangerous flies in Maine?
Mosquitoes can carry diseases like EEE and West Nile virus. Deer flies can transmit tularemia, but cases are rare.
What repels black flies best?
DEET-based repellents are most effective. Picaridin and oil of lemon eucalyptus also work well. Wearing a bug net is the best physical barrier.
Do all flies in Maine bite?
No. Many flies like house flies, fruit flies, and midges do not bite. Only females of biting species feed on blood.
Understanding the types of flies in Maine helps you prepare for outdoor activities. Whether you are hiking, fishing, or just sitting on your porch, knowing what to expect makes the experience more enjoyable. Use the tips above to reduce bites and stay comfortable. Maine’s natural beauty is worth a few bugs, but you don’t have to suffer.