Bugs and spiders in Wyoming
Bold jumping spiders, boxelder bugs, western conifer seed bugs and European paper wasps are recorded most often in Wyoming. The list here is short, and most of the common ones are either small spiders or insects that come indoors in autumn. What sets the state apart is what is established: the western black widow, hobo spider and Rocky Mountain wood tick.
Get advice if bitten
These are found in Wyoming. If you think one bit or stung you, call Poison Help at 1-800-222-1222; call 911 for trouble breathing or swelling.
Common in Wyoming
Established here or recorded often, most-recorded first.
Bold jumping spiderHarmlessCommon · 170 records
Boxelder bugHarmlessCommon · 166 records
Western conifer seed bugHarmlessCommon · 147 records
European paper waspBe carefulCommon · 135 records
Zebra jumping spiderHarmlessCommon · 134 records
Pill bugHarmlessCommon · 95 records
Asian lady beetleBe carefulCommon · 78 records
Western black widowGet adviceEstablished · 76 records
Hobo spiderBe carefulEstablished · 43 records
Barn funnel weaverHarmlessCommon · 39 records
Rocky Mountain wood tickGet adviceEstablished · 16 records
Brown dog tickGet adviceEstablished
House mosquitoBe carefulEstablishedWhat to watch for in Wyoming
The western black widow is established in Wyoming. A bite from an adult female can cause severe muscle pain and cramps, so get medical advice right away. The hobo spider is established too and is rated Be careful. For a worrying bite, call Poison Help at 1-800-222-1222.
The Rocky Mountain wood tick is established in Wyoming and can spread Rocky Mountain spotted fever, Colorado tick fever and tularemia. Remove any attached tick right away. The brown dog tick is established but mostly lives indoors with dogs. The American dog tick has a few records here, but it is not known to live in the state.
Through the year
- Spring
- Rocky Mountain wood ticks are active from snowmelt, and pill bugs turn up indoors in spring and after long rainy periods.
- Summer
- Zebra jumping spiders are out through late summer, western black widows are at their most active, and the occasional pavement ant swarm turns up in June and July.
- Fall
- Boxelder bugs show up from late August, western conifer seed bugs and Asian lady beetles follow, and male hobo spiders wander from August through October.
- Winter
- Barn funnel weavers live in houses year-round, and boxelder bugs and lady beetles stir on warm days in late winter.
Seen now and then
Recorded a few times; often brought in on plants, firewood or luggage.
Carolina wolf spiderBe carefulOccasional · 10 records
Yellow garden spiderBe carefulOccasional · 10 records
Pavement antHarmlessOccasional · 10 records
House flyBe carefulOccasional · 5 records
Woodlouse spiderHarmlessOccasional · 4 records
Odorous house antHarmlessOccasional · 4 records
Rough sowbugHarmlessOccasional · 4 records
Northern yellow sac spiderBe carefulOccasional · 3 records
Long-bodied cellar spiderHarmlessOccasional · 3 recordsRecorded, not established
Range maps don't place these here, but people have recorded them. Usually hitchhikers.
Lists come from research-grade iNaturalist sightings (Wyoming: 41,340 arthropod records) and, for dangerous species, published range maps. A species with few records may be a hitchhiker. Counts pulled Oct 18, 2026.