Bugs and spiders in Utah

What to watch for in Utah

The western black widow is the spider to know, and an adult female's bite can cause severe muscle pain and cramps. The Arizona bark scorpion is established in the southern low-desert areas, and its sting is very painful and can be dangerous for young children and older adults, so call Poison Help right away. The hobo spider is established and rated Be careful, with adult males searching for mates from August through October.

Ticks established in Utah are the Rocky Mountain wood tick, the brown dog tick and the western blacklegged tick, which is limited to a few counties and described by Utah State extension as rare. American dog tick records exist, but it is not known to live here. All of these can carry disease, so remove an attached tick promptly. Poison Help is 1-800-222-1222 if a bite worries you.

Through the year

Spring

Rocky Mountain wood ticks are out from snowmelt through about mid-July, and pill bugs and rough sowbugs turn up indoors after long wet spells.

Summer

Zebra jumping spiders are active on warm, sunny days, European paper wasps work around the outside of the house, and bark scorpions favor warm nights.

Fall

Boxelder bugs arrive from late August, hobo spider males wander in August through October, and western conifer seed bugs and Asian lady beetles follow.

Winter

Western black widows can overwinter in garages and crawl spaces, pavement ants may appear in heated homes, and Indianmeal moths and silverfish keep going indoors.