No confirmed photo of Honeybee
Honeybee
What the sources say
Venom: “The muscular poison sac will continue to pump venom” (University of Wisconsin-Extension, Cooperative Extension)
Wisconsin Bugs and Insects That Sting or Bite
Last checked November 3, 2026 against official sources.
On this page
This page lists 4 insects. 2 are venomous by official accounts. 2 are nonnative.
Not every species: no complete official list of Wisconsin 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 Wisconsin, in their own words:
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Yellow jackets
Stings. “Yellow jackets are responsible for a marked increase in stings and related problems from early August through September.” University of Wisconsin-Extension, Cooperative Extension
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Bees and wasps (including honeybee)
Venomous stings. “All other stinging bees and wasps have unbarbed stingers and can sting repeatedly if given the opportunity. The amount of venom injected will affect the severity of the reaction.” University of Wisconsin-Extension, Cooperative Extension
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Photo: Emmett Collins-Sussman · CC BY 4.0 · iNaturalist Spongy moth (caterpillars)
Caterpillar hairs can cause skin rashes and other reactions in some people (DNR). “In addition, the caterpillar hairs can cause skin rashes and other reactions in some people.” Wisconsin Department of Natural Resources
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Hairy or spiny caterpillars (some types)
Urticating hairs can cause blisters, burns or rashes (UW-Extension). “Some types of hairy or spiny caterpil-lars are covered with urticating, or stinging, hairs.” University of Wisconsin-Extension, Cooperative Extension
All 4 insects
Venomous species first, then A to Z. Do not handle them.
No confirmed photo of Yellow jackets
Yellow jackets
- Danger to people
- “Yellow jackets are responsible for a marked increase in stings and related problems from early August through September.” University of Wisconsin-Extension, Cooperative Extension
What the sources say
Venom: “All other stinging bees and wasps have unbarbed stingers and can sting repeatedly if given the opportunity. The amount of venom injected will affect the severity of the reaction.” (University of Wisconsin-Extension, Cooperative Extension)
Habitat: Some yellow jackets build nests of paper in rodent burrows or other cavities. (University of Wisconsin-Extension, Cooperative Extension)
Emerald ash borer
Agrilus planipennis
- 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 3/8 to 1/2 inch long and 1/8 inch wide; small enough to fit on a penny
- How to recognize it
- Slender, bullet-shaped body
- Signs on ash trees: S-shaped galleries under the bark and D-shaped exit holes about 1/8 inch across
- Tree symptoms: dead branches near the top, sprouts on the trunk, vertical bark cracks, and woodpecker 'blonding'
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.
- Danger to people
- “In addition, the caterpillar hairs can cause skin rashes and other reactions in some people.” Wisconsin Department of Natural Resources
- 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.
- Where in Wisconsin
- Quarantined counties; also reported from non-quarantined counties (DNR) Wisconsin Department of Natural Resources
When insects are active in Wisconsin
Records of insects in Wisconsin peak in June to August. They show when people record insects, not how many there are (about month bars).
- Yellow jacket stings increase markedly from early August through September. University of Wisconsin-Extension, Cooperative Extension
- Ticks: check especially in spring, summer and early fall; deer tick season runs from early April through November (UW-Extension 2010). Wisconsin Department of Health Services
- Spongy moth caterpillars rest on tree trunks and buildings in June and July. Wisconsin Department of Natural Resources
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 Wisconsin Department of Health Services:
- Ticks: do daily tick checks, use insect repellent and wear appropriate clothes outdoors. Wisconsin Department of Health Services
How to report
Rattlesnake sightings: call DNR 1-888-WDNRINFO (1-888-936-7463), or use the DNR Rare Species Observation Form / DNR Wildlife Switchboard ([email protected], 608-267-0866). Threatening wolves or wolf depredation: USDA-Wildlife Services (north 1-800-228-1368, south 1-800-433-0663). Spongy moth outside quarantined counties: 1-800-642-MOTH (6684). Other invasive species: DNR Report invasive species page. Feral pig sightings: DNR reporting form or USDA Wildlife Services (north 800-228-1368, south 800-433-0663). Wisconsin Department of Natural Resources, Bureau of Endangered Resources
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 Wisconsin.
Sources
- Wisconsin Animals. Wisconsin Department of Natural Resources. undated page; checked November 3, 2026.
- Outdoor Hazards in Wisconsin: A Guide to Insects, Plants, and Wildlife (G3564). University of Wisconsin-Extension, Cooperative Extension (Craven, Pellitteri, Renz). R-09-2010; checked November 3, 2026.
Quoted passages (4)
“All other stinging bees and wasps have unbarbed stingers and can sting repeatedly if given the opportunity. The amount of venom injected will affect the severity of the reaction.”
“Yellow jackets are responsible for a marked increase in stings and related problems from early August through September.”
“The muscular poison sac will continue to pump venom”
“Some types of hairy or spiny caterpil-lars are covered with urticating, or stinging, hairs.”
- Spongy moth. Wisconsin Department of Natural Resources. undated page; checked November 3, 2026.
Quoted passages (2)
“In addition, the caterpillar hairs can cause skin rashes and other reactions in some people.”
“Homeowners may see spongy moth caterpillars resting on tree trunks and buildings in June and July.”
- Emerald Ash Borer. Wisconsin Department of Natural Resources. undated page; checked November 3, 2026.
- Illnesses Spread by Ticks. Wisconsin Department of Health Services. undated page; checked November 3, 2026.
Quoted passages (1)
“There are many ways to prevent tick bites, including doing daily tick checks, using insect repellent, and wearing appropriate clothes when you are outdoors.”
- About Ticks. Wisconsin Department of Health Services. undated page; checked November 3, 2026.
Quoted passages (1)
“After you, your family members, or your pets spend time in the woods or areas with tall grass or brush, it is always important to check for ticks, especially in the spring, summer, and early fall.”
- Amphibian and Reptile Frequently Asked Questions #4 - Snakes, PUB-ER-670. Wisconsin Department of Natural Resources, Bureau of Endangered Resources (Kapfer 2011). 2011; checked November 3, 2026.
Quoted passages (1)
“If you have a confirmed rattlesnake sighting, you can report it by calling: 1-888-WDNRINFO (1-888-936-7463).”
- 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.