Aerial Yellow-jacket
Dolichovespula arenaria
What the sources say
Venom: “Social wasps use their sting and venom for defense and can sting multiple times.” (Montana State University Extension)
Montana Bugs and Insects That Sting or Bite
Last checked November 3, 2026 against official sources.
On this page
This page lists 20 insects and 6 ticks. 3 are venomous by official accounts. 4 are nonnative.
Not every species: no complete official list of Montana 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 Montana, in their own words:
-
Western Yellowjacket
Stings. “…most of our stings come from the western yellowjacket” Montana State University Extension
-
Blister beetles
Defensive oil can cause blistering. “…they have a defensive oil called cantharidin that can cause blistering” Montana State University Extension
Ticks (arachnids, not insects)
Official sources single out these ticks in Montana, in their own words:
-
Rocky Mountain Wood Tick
Disease vector per MSU and DPHHS. “It can transmit viral Colorado tick fever (CTF), Rocky Mountain spotted fever (RMSF), bovine anaplasmosis, and tularemia.” Montana State University Extension
-
Photo: Turner Brockman · CC BY-SA 4.0 · iNaturalist · resized American Dog Tick
Disease vector. “It is one of the major vectors of RMSF and can also transmit tularemia.” Montana State University Extension
All 20 insects and 6 ticks
Venomous species first, then A to Z. Do not handle them.
Bald-faced Hornet
Dolichovespula maculata
- 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
What the sources say
Venom: “Social wasps use their sting and venom for defense and can sting multiple times.” (Montana State University Extension)
No confirmed photo of Western Yellowjacket
Western Yellowjacket
Vespula pensylvanica
- Danger to people
- “…most of our stings come from the western yellowjacket” Montana State University Extension
What the sources say
Venom: “Social wasps use their sting and venom for defense and can sting multiple times.” (Montana State University Extension)
American Dog Tick
Dermacentor variabilis
- 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
- “It is one of the major vectors of RMSF and can also transmit tularemia.” Montana State University Extension
No confirmed photo of Bed Bug
Bed Bug
Cimex lectularius
- Venom
- No official source we use states whether this animal is venomous. That does not mean it is harmless: do not handle it.
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Black Blister Beetle
Epicauta pensylvanica
- 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 Blackjacket
Blackjacket
Vespula consobrina
- 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 Brown Dog Tick
Brown Dog Tick
Rhipicephalus sanguineus
- Venom
- No official source we use states whether this animal is venomous. That does not mean it is harmless: do not handle it.
Brown Marmorated Stink Bug
Halyomorpha halys
- Venom
- No official source we use states whether this animal is venomous. That does not mean it is harmless: do not handle it.
- Size
- Adults about 5/8 inch (about 17 mm) long; shield-shaped, almost as wide as long.
- How to recognize it
- Two white bands on the antennae; blunt front edge of head; smooth shoulder margin; dark bands at the tip of the membranous forewings; banded abdominal edge visible beside the wings
- Smooth (not spiny) shoulders; slightly larger than most native stink bugs
- Where in Montana
- Confirmed in Billings Montana State University Extension
No confirmed photo of Cuckoo Yellowjacket
Cuckoo Yellowjacket
Vespula infernalis
- Venom
- No official source we use states whether this animal is venomous. That does not mean it is harmless: do not handle it.
European Honey Bee
Apis mellifera
- Venom
- No official source we use states whether this animal is venomous. That does not mean it is harmless: do not handle it.
- Size
- About 10 percent smaller than a European honey bee, a difference too subtle to see without measurement or lab tests.
- How to recognize it
- Cannot be identified by eye: only DNA testing or microscopic measurements can tell it from a European honey bee.
- Clue is behavior and nest site: very defensive, and may nest in small cavities such as water meter boxes, old tires, house eaves or the ground.
European Paper Wasp
Polistes dominula
- 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 Forest Yellowjacket
Forest Yellowjacket
Vespula acadica
- Venom
- No official source we use states whether this animal is venomous. That does not mean it is harmless: do not handle it.
German Yellow-jacket
Vespula germanica
- 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 Golden Paper Wasp
Golden Paper Wasp
Polistes aurifer
- 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 Northern Aerial Yellowjacket
Northern Aerial Yellowjacket
Dolichovespula norvegicoides
- 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 Northern Paper Wasp
Northern Paper Wasp
Polistes fuscatus
- 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 Old World Yellowjacket
Old World 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.
No confirmed photo of Parasitic Yellowjacket
Parasitic Yellowjacket
Dolichovespula arctica
- 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 Prairie Yellowjacket
Prairie Yellowjacket
Vespula atropilosa
- 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 Rocky Mountain Aerial Yellowjacket
Rocky Mountain Aerial Yellowjacket
Dolichovespula alpicola
- 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 Rocky Mountain Wood Tick
Rocky Mountain Wood Tick
Dermacentor andersoni
- 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
- “It can transmit viral Colorado tick fever (CTF), Rocky Mountain spotted fever (RMSF), bovine anaplasmosis, and tularemia.” Montana State University Extension
No confirmed photo of Soft Ticks
Soft Ticks
Ornithodoros spp.
- 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 Spinose Ear Tick
Spinose Ear Tick
Otobius megnini
- 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 Western Encephalitis Mosquito
Western Encephalitis Mosquito
Culex tarsalis
- 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 Winter Tick
Winter Tick
Dermacentor albipictus
- Venom
- No official source we use states whether this animal is venomous. That does not mean it is harmless: do not handle it.
Insects and Bugs people confuse
Africanized Honey Bee or European honey bee?
Africanized Honey Bee Not stated
European honey bee Not stated
Not by sight: same species and same appearance. Differences are behavior and nest choice, and a confirmed ID needs testing.
Photos show typical adults; individuals vary. Never get close to compare.
When insects are active in Montana
Records of insects in Montana peak in July to August. They show when people record insects, not how many there are (about month bars).
- Ticks most active April to July, with most encounters in May. Montana Department of Public Health and Human Services
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.
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 Montana.
Sources
- Contact Us. Montana Fish, Wildlife & Parks. archived copy, captured October 19, 2026; checked November 3, 2026.
- Montana Field Guide: Insects, selected families only. Montana Natural Heritage Program (Montana State Library) with Montana Fish, Wildlife & Parks: Montana Field Guide. archived copy, captured January 17, 2026; checked November 3, 2026.
- Social Wasps in Montana. Montana State University Extension. undated page; checked November 3, 2026.
Quoted passages (2)
“Social wasps use their sting and venom for defense and can sting multiple times.”
“…most of our stings come from the western yellowjacket”
- Tickborne Illnesses. Montana Department of Public Health and Human Services. archived copy, captured May 18, 2026; checked November 3, 2026.
Quoted passages (1)
“Ticks are most active from April through July, but Montanans are most likely to encounter ticks in May.”
- It's Tick Season (fact sheet). Montana State University Extension. May 2022; checked November 3, 2026.
Quoted passages (2)
“It can transmit viral Colorado tick fever (CTF), Rocky Mountain spotted fever (RMSF), bovine anaplasmosis, and tularemia.”
“It is one of the major vectors of RMSF and can also transmit tularemia.”
- Montana Field Guide: Spiders class Arachnida (family species lists). Montana Natural Heritage Program (Montana State Library) with Montana Fish, Wildlife & Parks: Montana Field Guide. archived copy, captured December 3, 2021; checked November 3, 2026.
- Brown Marmorated Stink Bug in Montana. Montana State University Extension. undated page; checked November 3, 2026.
- Blister Beetles in the Yard and Garden. Montana State University Extension. undated page; checked November 3, 2026.
Quoted passages (1)
“…they have a defensive oil called cantharidin that can cause blistering”
- 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.