No confirmed photo of American / Alaska Yellowjacket
American / Alaska Yellowjacket
Vespula alascensis
- Venom
- No official source we use states whether this animal is venomous. That does not mean it is harmless: do not handle it.
Maine Bugs and Insects That Sting or Bite
Last checked November 3, 2026 against official sources.
On this page
This page lists 12 insects. 4 are nonnative.
Not every species: no complete official list of Maine insects exists, so this page covers the ones state and Extension sources name. How lists are built.
Which insects can hurt you
Official sources single out these insects in Maine, in their own words:
-
Browntail Moth (caterpillar hairs)
Maine CDC. “The microscopic hairs found on browntail moth caterpillars, shed skins, and cocoons can cause skin reactions and breathing problems.” Maine DHHS
-
Mosquitoes
Maine CDC. “Mosquitoes in Maine can carry viruses that can cause several illnesses. These include: Eastern Equine Encephalitis virus (EEE) Jamestown Canyon virus (JCV) West Nile virus (WNV)” Maine DHHS
-
Hornets, wasps and yellowjackets (family Vespidae)
Stinging. “Most vespid wasps are social insects and most are capable of repeatedly stinging if they feel threatened or feel their nest is in danger.” University of Maine Cooperative Extension
-
Deer flies (genus Chrysops)
Painful bites. “Significant allergic reactions can develop for some people.” University of Maine Cooperative Extension
-
Hickory Tussock Moth caterpillar
Hairs can cause a very itchy rash in some people (UMaine Extension). “…handle with care as the hairs on these can cause a very itchy rash for some people” University of Maine Cooperative Extension
All 12 insects
From A to Z. Do not handle them.
No confirmed photo of Asian Longhorned Beetle
Asian Longhorned Beetle
Anoplophora glabripennis
- Venom
- No official source we use states whether this animal is venomous. That does not mean it is harmless: do not handle it.
Bald-faced Hornet
Dolichovespula maculata
- Venom
- No official source we use states whether this animal is venomous. That does not mean it is harmless: do not handle it.
- Size
- Missouri: workers 1/2 to 3/4 inch, queens 3/4 inch. University of Maryland: workers 5/8 to 3/4 inch, queens just over an inch. Penn State gives 13 to 20 mm for the queen and her offspring.
- How to recognize it
- Not yellow, unlike typical yellowjackets; larger, black and ivory
- Large, rounded, gray paper nest hanging in trees or shrubs, sometimes on buildings
- Nest entrance is the lowest opening of the cone- or egg-shaped nest
No confirmed photo of Black flies (family Simuliidae)
Black flies (family Simuliidae)
- Venom
- No official source we use states whether this animal is venomous. That does not mean it is harmless: do not handle it.
No confirmed photo of Browntail Moth
Browntail Moth
Euproctis chrysorrhoea
- Venom
- No official source we use states whether this animal is venomous. That does not mean it is harmless: do not handle it.
- Danger to people
- “The microscopic hairs found on browntail moth caterpillars, shed skins, and cocoons can cause skin reactions and breathing problems.” Maine DHHS
- Where in Maine
- Southern and coastal Maine Maine Department of Agriculture, Conservation and Forestry, Maine Forest Service
Common Aerial Yellowjacket
Dolichovespula arenaria
- Venom
- No official source we use states whether this animal is venomous. That does not mean it is harmless: do not handle it.
No confirmed photo of Deer flies (genus Chrysops)
Deer flies (genus Chrysops)
- Venom
- No official source we use states whether this animal is venomous. That does not mean it is harmless: do not handle it.
- Danger to people
- “Significant allergic reactions can develop for some people.” University of Maine Cooperative Extension
Emerald Ash Borer
- Venom
- No official source we use states whether this animal is venomous. That does not mean it is harmless: do not handle it.
Hemlock Woolly Adelgid
- Venom
- No official source we use states whether this animal is venomous. That does not mean it is harmless: do not handle it.
No confirmed photo of Hickory Tussock Moth (caterpillar)
Hickory Tussock Moth (caterpillar)
- Venom
- No official source we use states whether this animal is venomous. That does not mean it is harmless: do not handle it.
No confirmed photo of Mosquitoes (about 45 species in Maine)
Mosquitoes (about 45 species in Maine)
- Venom
- No official source we use states whether this animal is venomous. That does not mean it is harmless: do not handle it.
Spongy Moth
Lymantria dispar
- Venom
- No official source we use states whether this animal is venomous. That does not mean it is harmless: do not handle it.
- Size
- Mature caterpillars 1.5 to 2.5 inches long (Missouri: up to 2 inches). Male moths about 1.5-inch wingspread; females larger, about 2 to 2.5 inches.
- How to recognize it
- Older caterpillars have a double row of five pairs of blue spots followed by six pairs of red spots down the back, and tufts of hair on each segment.
- Spongy moth caterpillars do not make silk webs or tents.
- Females are white and cannot fly; males are brown and fly erratically in daytime in July and August.
When insects are active in Maine
Records of insects in Maine peak in June to August. They show when people record insects, not how many there are (about month bars).
- Browntail moth caterpillars active May to early July (2026). Maine DHHS
- Ticks can be active any time the temperature is above freezing. Maine DHHS
- Mosquito-borne virus surveillance reports run July to September. Maine DHHS
- Hornets, wasps and yellowjackets peak in mid to late summer. University of Maine Cooperative Extension
If you are bitten or stung
Call 911 or Poison Help at 1-800-222-1222 right away. Poison Help connects you to your local poison center, any time of day.
Official advice from Maine Department of Inland Fisheries and Wildlife, Maine DHHS and Northern New England Poison Center:
- Bears: bring in bird feeders and remove food attractants while bears are active (April 1 to November 1). Maine Department of Inland Fisheries and Wildlife
- Ticks and mosquitoes: use EPA-approved repellents (Maine CDC). Maine DHHS
- Bites, stings or suspected poisoning: call 911 or Poison Help at 1-800-222-1222 (Northern New England Poison Center serves Maine). Northern New England Poison Center
About this list
Venom labels come only from official sources and link to them; "Not stated" never means harmless. How labels work.
"Nonnative" and "Invasive" follow the wording of the source list. See invasive species in Maine.
Sources
- Listed Species (Maine Endangered and Threatened Species). Maine Department of Inland Fisheries and Wildlife. undated page; checked November 3, 2026.
- Hornets Wasps And Yellowjackets (Home and Garden IPM fact sheet). University of Maine Cooperative Extension. undated page; checked November 3, 2026.
Quoted passages (2)
“Most vespid wasps are social insects and most are capable of repeatedly stinging if they feel threatened or feel their nest is in danger.”
“They can be a significant nuisance throughout Maine, particularly in mid to late summer when colonies reach peak numbers.”
- Browntail Moth—Euproctis chrysorrhoea (Got Pests?). Maine Department of Agriculture, Conservation and Forestry. undated page; checked November 3, 2026.
- Health Advisory 2026PHADV008: Browntail moth. Maine Center for Disease Control and Prevention (Maine DHHS). Maine Health Alert Network advisory, May 2026; checked November 3, 2026.
Quoted passages (2)
“The microscopic hairs found on browntail moth caterpillars, shed skins, and cocoons can cause skin reactions and breathing problems.”
“This year, browntail moth caterpillars emerged from their winter webs later than in previous years and will be active from May to early July.”
- Invasive Threats to Maine's Forests and Trees. Maine Department of Agriculture, Conservation and Forestry, Maine Forest Service. undated page; checked November 3, 2026.
- Bald Faced Hornet (Home and Garden IPM fact sheet). University of Maine Cooperative Extension. undated page; checked November 3, 2026.
- Black Flies (Home and Garden IPM fact sheet). University of Maine Cooperative Extension. undated page; checked November 3, 2026.
- Deer Flies (Home and Garden IPM fact sheet). University of Maine Cooperative Extension. undated page; checked November 3, 2026.
Quoted passages (1)
“Significant allergic reactions can develop for some people.”
- Vector-borne diseases. Maine Center for Disease Control and Prevention (Maine DHHS). undated page; checked November 3, 2026.
Quoted passages (3)
“Mosquitoes in Maine can carry viruses that can cause several illnesses. These include: Eastern Equine Encephalitis virus (EEE) Jamestown Canyon virus (JCV) West Nile virus (WNV)”
“Using an EPA-approved repellent when spending time outdoors can reduce the risk of bites.”
“The results are published in weekly Arboviral Surveillance Reports from July to September each year.”
- Hickory Tussock Moth (Home and Garden IPM fact sheet). University of Maine Cooperative Extension. undated page; checked November 3, 2026.
Quoted passages (1)
“…handle with care as the hairs on these can cause a very itchy rash for some people”
- Lymantria Dispar (Home and Garden IPM fact sheet). University of Maine Cooperative Extension. undated page; checked November 3, 2026.
- Asian Longhorned Beetle (Home and Garden IPM fact sheet). University of Maine Cooperative Extension. undated page; checked November 3, 2026.
- Bear (mammal species page). Maine Department of Inland Fisheries and Wildlife. undated page; checked November 3, 2026.
Quoted passages (1)
“To prevent conflicts with black bears each year when bears are active (April 1-November 1):”
- Northern New England Poison Center - Serving Maine, New Hampshire & Vermont. Northern New England Poison Center (regional poison control center serving Maine). undated page; checked November 3, 2026.
Quoted passages (1)
“Northern New England Poison Center - Serving Maine, New Hampshire & Vermont”
- Tick and Mosquito Frequently Asked Questions. Maine Center for Disease Control and Prevention (Maine DHHS). undated page; checked November 3, 2026.
Quoted passages (1)
“Any time the temperature is above freezing, ticks could be out.”
- GBIF.org occurrence records, human observations licensed CC0 1.0 or CC BY 4.0 only, accessed November 3, 2026. The datasets behind these counts are listed on our Sources page.