Bug FAQPacific Tent Caterpillar
Malacosoma constricta · Order: Lepidoptera · Family: Lasiocampidae
Source: Wikipedia
Pacific tent caterpillars have speckled sides, orange hairs on top and gray-cream hairs on the sides, and a dark-blue head. They live on oak trees in California, Oregon and Washington and spin small tents up to about 10 cm wide. The larvae eat oak leaves and can strip branches, but they usually cause only aesthetic damage.
Source: Wikipedia
How to recognize it
The caterpillar’s sides are speckled, the top is covered with orange hairs, the sides have gray-cream hairs, and the head is dark blue.
Source: Wikipedia
Is it a pest in the house?
When many are present they may be a nuisance, though they rarely cause serious damage to oak trees.
Source: Wikipedia
Where it lives
It is found on oak trees in California, Oregon and Washington. It builds a simple tent that can be up to 10 cm across.
Source: Wikipedia
What it eats
Larvae feed on oak leaves and can defoliate branches.
Source: Wikipedia
Life cycle
Eggs are laid in yellow clumps on sticks. Caterpillars feed together outside the tent and only enter it to molt.
Source: Wikipedia
Where it comes from
The species is native to North America. It is recorded from California, Oregon and Washington.
Source: Wikipedia
Lookalikes
Western tent caterpillars and forest tent caterpillars also occur in California oak woodlands.
Source: Wikipedia
Where it is found in the US
Recorded in 5 of 51 states and DC. Most records: California, Oregon, Washington, Arizona, Wisconsin.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Status: native in North America; native in United States. Source: iNaturalist
Months it is reported in the US
Source: GBIF
More photos
Questions people ask
How can I identify a Pacific tent caterpillar?
Look for speckled sides, orange hairs on top, gray-cream hairs on the sides, and a dark-blue head.
Source: Wikipedia
Where are Pacific tent caterpillars found?
They occur on oak trees in California, Oregon and Washington.
Source: Wikipedia
Do they damage trees?
The larvae eat oak leaves and can strip branches, but they usually cause only cosmetic damage.
Source: Wikipedia
Are they a nuisance?
Yes, large numbers can be a nuisance to people, though they rarely cause major harm.
Source: Wikipedia
Same family (Lasiocampidae)
Eastern Tent Caterpillar MothMalacosoma americanaDamages trees, gardens or crops
Forest Tent Caterpillar MothMalacosoma disstriaDamages trees, gardens or crops
Fox MothMacrothylacia rubi
Oak EggarLasiocampa quercus
Drinker MothEuthrix potatoria
Western Tent Caterpillar MothMalacosoma californicaDamages trees, gardens or cropsSources
- Wikipedia: https://en.wikipedia.org/wiki/Malacosoma_constricta
Look it up elsewhere: GBIF · iNaturalist · BugGuide · Wikipedia
Text written 2026-10-23 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-23.