Explanation of Names
Malacosoma disstria Hübner, 1820
Identification
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
Range
widely dist., but more common east of Mississippi River -
Map (MPG)
Habitat
on or near host tree species
Season
Adults mostly fly from April to August (
MPG)
Caterpillars typically April-June.
Food
larvae feed on leaves of alder, basswood, birch, cherry, oak, poplar, willow
Life Cycle
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 egg masses surrounding tree branches. Unlike Eastern Tent Caterpillar, this species does not form silken tents (Florida Dept. Agriculture).
Remarks
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
The species name disstria is a simple noun, so does not follow the genus name in gender.
(
Malacosoma is neuter, so adjectivic species names end -um instead of -a.
(1))
Populations outbreaks on
Populus tremuloides have been found when the ozone is elevated as it reduces tree growth, lowers concentrations of phenolic glycosides, and increases cuticular waxes.
(2)
Telemonus clisiocampanae, a wasp in the Scelionidae family, parasitizes the eggs
(3) See Also
Eastern Tent Caterpillar (
Malacosoma americanum) has an unbroken cream/white line along its back, and a dark face.
The adult Malacosoma americanum have light colored transverse lines
Print References
Covell, p. 54, plate 11#3
(4)
Wagner, p. 227--photo of caterpillar, specimen of adult
(5)Internet References
Moth Photographers Group - range map, photos of living and pinned adults.
Featured Creatures - James R. Meeker, Florida Department of Agriculture