Tent caterpillar
Tent caterpillars are social moth larvae in the genus *Malacosoma*, family Lasiocampidae, known for building silk tents in tree branches and for periodically defoliating host trees.
Tent caterpillars are social moth larvae in the genus *Malacosoma*, family Lasiocampidae, known for building silk tents in tree branches and for periodically defoliating host trees. The common name refers to this tent-like silk structure, and several species occur in North America and Eurasia.
Description
Tent caterpillars are moderately sized caterpillars in the genus *Malacosoma*. They are social, often active during the day, and are known for conspicuous silk tents built in host trees.
Distribution and species
The group includes 26 described species, with six occurring in North America and the rest in Eurasia. Natural Resources Canada identifies the forest, eastern and western tent caterpillars as North American species.
Ecology and host plants
Tent caterpillars feed on deciduous trees and shrubs, with host plants varying by species and region. Documented hosts include cherry, apple, birch, willow, aspen, poplar, oak and alder.
Damage and pest status
They are often treated as pests because feeding by large colonies can defoliate trees and reduce growth, although severity varies by species and host plant. Outbreaks can recur at multi-year intervals.
Control and management
Recommended control measures include removing egg masses in winter, clipping small tents in spring, and using *Bacillus thuringiensis* against young larvae.
Key facts
- Tent caterpillars are the larvae of moths in the genus *Malacosoma*.
- They are recognized by the silken tents they build in tree branches.
- They are among the most social caterpillars and often feed in groups.
- They are considered pests because outbreaks can defoliate trees.
- North American species include the eastern tent caterpillar, forest tent caterpillar and western tent caterpillar.
Tent caterpillars are relevant across Canada because forest tent caterpillars are native and can periodically outbreak in many regions, affecting deciduous trees; Canadian government and provincial forestry resources provide control guidance.[5][7][8]
Frequently asked questions
What is a tent caterpillar?
Why are tent caterpillars called “tent” caterpillars?
Are tent caterpillars harmful to trees?
How many tent caterpillar species are there?
Which trees do they feed on?
How are tent caterpillars controlled?
References
- University of Kentucky Entomology — https://entomology.mgcafe.uky.edu/ef423Supports: Eastern tent caterpillar identity, pest status, host plants, and control measures.
- Wikipedia — https://en.wikipedia.org/wiki/Tent_caterpillarSupports: Genus-level overview, number of described species, distribution, and general behavioural traits.
- Natural Resources Canada — https://tidcf.nrcan.gc.ca/en/insects/factsheet/9373Supports: Northern tent caterpillar host plants in Canada.
- Urban Ag Council — https://urbanagcouncil.com/article/the-tent-caterpillars/Supports: General description, distribution, host range, and damage.
- Government of Canada — https://www.canada.ca/en/health-canada/services/pest-control-tips/tent-caterpillars.htmlSupports: Tent caterpillar behaviour, outbreak cycles, and control methods.
- State University of New York College of Environmental Science and Forestry — https://www.esf.edu/ecenter/eis/tentcatterpillars.phpSupports: Outbreak periodicity and pest importance in New York.
- Government of Manitoba — https://www.gov.mb.ca/nrnd/forest/pubs/forest_lands/health/forest_tent_caterpillar_brochure.pdfSupports: Forest tent caterpillar as a serious defoliator in Canada and the United States.
- Natural Resources Canada — https://natural-resources.canada.ca/forests-forestry/insects-disturbances/forest-tent-caterpillarSupports: Forest tent caterpillar native status, related species, and host trees.