Bugs and spiders in Washington

What to watch for in Washington

The western black widow is established in Washington. It is common east of the Cascades, with a few small populations to the west. A bite from an adult female can cause severe muscle pain and cramps, so get medical advice right away. The hobo spider is established and rated Be careful. Brown widow records exist, but it is not known to live here. Poison Help is 1-800-222-1222 if a bite worries you.

For ticks, the western blacklegged tick is established in parts of the state, in western Washington and on the east slopes of the Cascades, and it can spread Lyme disease and anaplasmosis. The Rocky Mountain wood tick is established in eastern Washington. The brown dog tick is established but mostly lives indoors with dogs. American dog tick records exist, but it is not known to live in Washington.

Through the year

Spring

Pill bugs and rough sowbugs turn up after long rainy spells, western blacklegged tick nymphs are active, and eastern Washington sees Rocky Mountain wood ticks from snowmelt into July.

Summer

Zebra jumping spiders are out on warm, sunny days, European paper wasps work around the house, and western black widows are at their most active.

Fall

Giant house spiders peak in late August and September, then Asian lady beetles, western conifer seed bugs and brown marmorated stink bugs move in, and European earwigs show up indoors.

Winter

Long-bodied cellar spiders, false black widows and common house spiders stay in heated homes all year, and Indianmeal moths are most often noticed from November through February.