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Taxonomy

See also list of butterflies and moths

tiger moth, (subfamily Arctiinae), any of about 11,000 species of moths. Many have furry or hairy larvae (caterpillars) known as woolly bears.

Physical description

The common name “tiger moth” is derived from that of one of its most common genera, Grammia, which have dark wings with red or orange spots and white stripes, sometimes displayed in striking geometric patterns. Most adults have thick furry bodies and wings that may be almost solid white, or dark with white, orange, or green markings. When at rest the wings are folded rooflike over the body.

The bright warning coloration displayed by some arctiids is associated with distastefulness, thus protecting the moths from predation.

Mute swan with cygnet. (birds)
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Major genera and species

The fall webworm (Hyphantria cunea) is a serious pest whose caterpillars construct webs over the leaves at the end of branches. Sometimes large areas are covered with silken sheets. They pupate above ground in cocoons made of larval hairs and silk. These silken webs can be distinguished from those of the unrelated tent caterpillars (Malacosoma species), as the latter construct silken retreats in branch forks deep within the canopy.

A typical arctiid, the Isabella tiger moth (Pyrrharctia isabella), emerges in spring and attains a wingspan of 37 to 50 mm (1.5 to 2 inches). Black spots mark its abdomen and yellow wings. The larva, known as the banded woolly bear, is brown in the middle and black at both ends. According to superstition the length of the black ends predicts the severity of the coming winter: The shorter the black ends, the milder the weather.

Footman moths and lichen moths are also members of the tiger moth subfamily (they were formerly placed in their own subfamily, Lithosiinae). Most adults are drab browns and grays, though some species are colorful. The larvae typically feed on lichen.

The Editors of Encyclopaedia Britannica This article was most recently revised and updated by Melissa Petruzzello.