Megalopygidae

Common Name

Flannel Moths

Overview

Megalopygidae is a family of moths known for their distinctive, densely hairy caterpillars. These creatures are found predominantly in the Americas, with a concentration in tropical and subtropical regions.

Taxonomy

Key Characteristics

  • Adults: Flannel moths have silky, furry bodies and wings. They are often adorned with vivid patterns and colors.
  • Larvae: Known commonly as asp caterpillars, they are covered in long, hair-like setae which can deliver a painful sting upon contact.
  • Wingspan: Ranges from approximately 25 to 45 mm in most species.

Life Cycle

Megalopygidae undergoes complete metamorphosis with four stages:

  1. Egg: Females lay clusters of eggs on host plants.
  2. Larvae: Caterpillars are covered in venomous spines concealed by hair, deterring predators.
  3. Pupa: Pupation occurs in a loosely woven cocoon.
  4. Adult: Emerge from the cocoon to continue the reproductive cycle.

Behavior and Ecology

  • Feeding: Caterpillars primarily feed on the leaves of trees and shrubs, while adults feed on nectar.
  • Habitat: These moths are generally found in forests, gardens, and areas with abundant vegetation.
  • Defensive Mechanisms: The hairy spines of the caterpillars can cause severe irritation and pain upon contact with skin, serving as an effective defense against predators.

Notable Species

  • Puss Moth (Megalopyge opercularis): Known for its extremely painful sting from the larvae.
  • Black-waved Flannel Moth (Megalopyge crispata): Features striking black and white hairs on its larvae.

Conservation

There is no widespread conservation concern for Megalopygidae as a family, though specific habitats may be threatened by deforestation and urbanization.

Significance to Humans

  • Medical Importance: The sting of the caterpillars can cause severe pain, rashes, and in some instances, systemic reactions.
  • Ecological Role: Caterpillars play a role in plant community dynamics by feeding on foliage, influencing plant health and growth.

Fun Fact

  • Unique Defense: The venomous spines on the caterpillars can cause intense pain, sometimes described as similar to broken bones or blunt force trauma.
  • Thermometers: Historic folklore suggests that the flannel moth caterpillar’s presence and behavior could predict weather changes.
  • Fluffy Appearance: Their fluffy, benign-looking appearance often belies the painful sting they can deliver.
  • Broad Distribution: Though concentrated in the Americas, flannel moths can be found as far north as the eastern United States and as far south as Argentina.
  • Mistaken Identity: The fuzzy larvae are often mistaken for harmless objects like cotton or lint, leading to unexpected painful encounters.