Forest Tent Caterpillar Moth

Malacosoma disstria · Order: Lepidoptera · Family: Lasiocampidae

Also called: Forest Tent Caterpillar

Damages trees, gardens or crops. The forest tent caterpillar can defoliate and weaken a wide range of deciduous trees and shrubs.

Source: Wikipedia

Forest Tent Caterpillar Moth
Photo: unknown, CC0

Mature larvae are about 2 to 2.5 inches long and have striking blue stripes with yellow edges, plus a white spot on each abdominal segment. When their numbers surge in spring, they feed heavily on many hardwoods, which can stress or damage the trees.

Source: Wikipedia

How to recognize it

Each abdominal segment has a white spot that gets wider toward the head.

Source: Wikipedia

Size

Fully grown larvae measure roughly 50 to 64 mm in length. Adult moths have a wingspan of about 30 mm.

Source: Wikipedia

Where it lives

The species occurs across North America, especially in the eastern states. Adults lay eggs in the summer on trees such as oak, sweetgum, tupelo, aspen and sugar maple.

Source: Wikipedia

What it eats

Larvae feed on many kinds of deciduous trees and shrubs.

Source: Wikipedia

Life cycle

Eggs hatch the following spring. A single egg mass can produce 50 to 200 larvae that stay together for most of their development.

Source: Wikipedia

When you see it

They become a problem when larval populations explode in spring. Adults are nocturnal, flying soon after nightfall and resting before dawn.

Source: Wikipedia

Where it comes from

It is native to North America.

Source: Wikipedia

Where it is found in the US

Recorded in 49 of 51 states and DC. Most records: Texas, Florida, New York, South Carolina, Vermont, Minnesota, Massachusetts, North Carolina.

Darker = more records. Counts are museum and citizen-science records, not population size.

Source: GBIF

Status: native in North America; native in United States; native in Canada. Source: iNaturalist

Months it is reported in the US

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Source: GBIF

More photos

Questions people ask

Do forest tent caterpillars damage trees?

Yes, when their numbers are high in spring they can heavily defoliate many hardwood trees and shrubs.

Source: Wikipedia

Same family (Lasiocampidae)

Sources

  • Wikipedia: https://en.wikipedia.org/wiki/Forest_tent_caterpillar_moth

Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia

Text written 2026-10-22 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-22.

How this page works

This is one bug's fact sheet. The colored box at the top says whether it is dangerous. Sections below cover how to recognize it, whether it is a pest, and how to deal with it. The US map shows which states have records; tap a state to see other bugs there.

Every fact on Bug FAQ comes from a named source (university extension sites, government agencies, GBIF, iNaturalist, Wikipedia). The source is linked next to each section. If we have no source for something, we leave it out.