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Hag Moth(Phobetron pithecium)

The hag moth of the Limacodidae family is indigenous to the eastern parts of North America. Its name is a result of the shabby, brown hair covering their body. During their larva stage, they are even referred to as a slug monkey.

Hag Moth


Scientific Classification

  • Family: Limacodidae
  • Genus: Phobetron
  • Scientific Name: Phobetron pithecium

Description and Identification


The caterpillar has a unique furry appearance, closely resembling a tarantula. One of its prominent features is the six pairs of projections it has on both sides of its body. Three of the curly appendages protruding from each side are long, while the other three are short. Though the projections look like legs, they are not, as their real legs lie within their body.  The larva has dense, brown hair all over its body and reaches a length of about 2.5 cm.

Hag Moth Larvae


Hag Moth Caterpillar



The pupa remains enclosed within a silken cocoon, looking like a cup, with a circular escape hatch.

Adult Moth

Sexual Dimorphism: Present

Color and Appearance: When the wings are opened they are mottled brown, translucent and bright in males, and opaque and a little dull in females. When the wings are closed, the pattern does not change much, though the translucence may not be prominently visible.

Females are bigger than males, also having yellow puffs of hair on their legs.

Average wingspan: 3 cm

Flight pattern: Not recorded

Season: May to September

Phobetron pithecium



The eggs are small and transparent through which the larva’s development can be visible.

Hag Moth Egg


Quick Facts

Other NamesSlug monkey (for the larva)
DistributionEastern parts of North America
HabitatOrchards, fields, forests, and woods
PredatorsBats, and wasps
Lifespan of AdultsNot recorded
Host plantsAsh, cherry, birch, cedar, apple, dogwood, chestnut, oak, walnut, willow, hickory, and persimmon
Adult dietNectar, mostly of their host plants

Did You Know

  • The male and female hag moth mimics a wasp and a bee, respectively, which helps them put up a strong defense against their predators.
  • Toxin glands are known to be located on the hag moth’s spines, which releases toxins upon contact, irritating the human skin. However, entomologist David. L Wagner tested the sting of this moth on himself but did not experience any harmful reactions.
Monkey Slug


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Scientific Classification

  • Family: Limacodidae
  • Genus: Phobetron
  • Scientific Name: Phobetron pithecium