Explanation of Names
Malacosoma disstria Hübner, 1820
Adult: stout-bodied; forewing light brown with two darker, thin parallel lines extending across mid-portion, the area between often being dark and appearing as a single broad, dark band
Larvae: dark-gray to brownish-black background body color, highlighted by broad, pale-blue lines and thin, broken yellow lines extending along each side; dorsum of each abdominal segment has distinct whitish keyhole or shoeprint-shaped marking; body has fine, whitish, and sparsely distributed hairs
widely dist., but more common east of Mississippi River - Map
on or near host tree species
Adults mostly fly from April to August (MPG
Caterpillars typically April-June.
larvae feed on leaves of alder, basswood, birch, cherry, oak, poplar, willow
One generation per year; larvae spin silken mats on tree trunks and large branches where they congregate to molt or rest from feeding; larvae also deposit silk in strands along which they travel to and from feeding sites; overwinters as larva in masses surrounding tree branches. (Unlike Eastern Tent Caterpillar, this species does not form silken tents.)
In Canada, some outbreaks of this pest have persisted for 6 years and have been extremely widespread. In 1962 over 139,000 square miles of defoliation occurred in the four western provinces. However, reduced growth and some branch killing are the usually extent of damage. - UBC
Eastern Tent Caterpillar
) has an unbroken cream/white line along its back, and a dark face.
The adult Malacosoma americanum have light colored transverse lines
Covell, p. 54, plate 11#3 (1)
Wagner, p. 227--photo of caterpillar, specimen of adult (2)
Moth Photographers Group
- range map, photos of living and pinned adults.
- James R. Meeker, Florida Department of Agriculture