Other Common Names
Eastern Tent Caterpillar (larva)
Synonyms and other taxonomic changes
Malacosoma americana (alternate spelling)
Numbers
one of 6 species in this genus in North America listed at
All-Leps
common
Size
Caterpillar length to 57 mm (2¼ in)
(2)Identification
Adult: body and wings warm fawn brown; forewing with white AM and PM lines; median area sometimes white
(1)
wings of male are darker and more brownish; wings of female are paler and more yellowish
Larva: distinguished by a solid cream/white line along the dorsum (middle of the back). Sides of the body are marked with blue, black, orange and white. Dark face.
Range
Eastern and central US to the Rockies
(2) and Canada from Nova Scotia to Alberta
Season
Tents appear in early spring, and caterpillars are seen until early summer
(3).
Moths fly from late May to June
(1).
Food
larvae feed on leaves of many trees and shrubs but particularly members of the rose family such as apple, cherry, and crabapple
(1)Life Cycle
Female deposits egg mass on twig where it overwinters
(2).
Larvae emerge in spring and begin building their tent which they continue to expand as they grow.
Fully grown caterpillars eventually disperse and find a place to pupate.
one generation per year; overwinters as an egg
Remarks
A good overview of larval habits (shelter building, feeding, thermoregulation, anti-predator defense, trail making and recruitment) appears on
this page by Terrence Fitzgerald.
See Also
adult
Forest Tent Caterpillar (
M. disstria) forewing has dark AM and PM lines (not pale, as in
M. americana)
adult
Western Tent Caterpillar (
M. californica) is slightly smaller but otherwise similar and probably indistinguishable from
M. americana in areas where their ranges overlap (Quebec to Alberta and adjacent states)
compare photos of all 3 species at CBIF
larva of
Forest Tent Caterpillar (
Malacosoma disstria) has a broken dorsal line forming keyhole or footprint shapes along its back, and generally more blue on its body, including the face. Larvae form silken mats where they congregate, not tents.
