Malacosoma americanum (Eastern Tent Caterpillar Moth)

 

04/07/2026

 

Samuel Clifford

 

Classification:

 

Kingdom - Animalia

Phylum - Arthropoda

Class - Insecta

Order - Lepidoptera 

Family - Lasiocampidae

Genus - Malacosoma

Species - disstria

 

Only a few days after viewing the Forest Tent Caterpillar Moth I had the blessing of viewing its similar relative the Eastern Tent Caterpillar Moth. I viewed this species in Griffin GA. This species is very common in the Eastern United States & also is sporadically recorded further west into areas like Colorado and Montana.

 

Life Cycle:

 

  • The eggs of Malacosoma americanum are laid in mass & encircle branches. They are then covered with a shiny, black/greyish varnish-like material. Usually the egg mass contains around 200 - 300 eggs. Within around three weeks the fully formed caterpillars can be found.

 

  • Soon after the larvae hatched, they begin constructing a silk tent which is typical of their species. These tents commonly occur in the crotches & forks of branches and can be seen in spring and early summer. As they grow they expand the tent. The Caterpillars have defensive hairs that can cause allergies. They will also vigorously thrash the anterior part of their bodies when they detect predators. I experienced both the anterior thrashing and allergy causing hairs when interacting with a member of this species.

 

  • Pupation occurs when the larvae are fully grown (around 2-2.5 inches). They then leave their communal tents & disperse to a protected location to build a cocoon that is white to yellowish in color. The pupal stage lasts around 2-4 weeks.

 

  • The adult moths are reddish brown in color and their wingspan is around 2.5 cm. The females are larger than the males. The moths breed after emergence & only once a year.

 

Image taken by Darah Leffler

Sources:

 

Chisholm, Ian, et al. “Eastern Tent Caterpillar (Malacosoma americanum).” Animal Diversity Web, University of Michigan Museum of Zoology. https://animaldiversity.org/accounts/Malacosoma_americanum/

 

Penn State Extension. “Eastern Tent Caterpillar.” Penn State College of Agricultural Sciences. https://extension.psu.edu/eastern-tent-caterpillar

 

“Malacosoma americanum.” Wikipedia: The Free Encyclopedia.

https://en.wikipedia.org/wiki/Malacosoma_americanum