masked birch caterpillar

insect larva

Written by

The Information Architects of Encyclopaedia Britannica

Last updated

July 23, 2026

Quick Summary

The masked birch caterpillar is the larval stage of the moth Drepana arcuata. Caterpillars are the larval form of butterflies and moths, characterized by cylindrical bodies with true legs on the thorax and prolegs on the abdomen.1

Masked birch caterpillars are known for their unique defense mechanism: they produce vibratory signals by drumming their mandibles and scratching their legs against leaf surfaces to ward off other caterpillars of the same species. This behavior helps them defend their territory.1

Caterpillars, in general, are known for their voracious appetites and can cause significant damage to plants by eating leaves. However, they are also a crucial part of food webs, serving as a primary food source for many animals, including songbirds.1

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

5 Britannica Sources

Ask Britannica AI about this topic

Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.

caterpillar
Caterpillar defenses
The masked birch caterpillar (Drepana arcuata) produces vibratory signals in order to defend its territory against intruders of the same species; it produces the vibrations by drumming its mandibles on the leaf surface and by scratching its legs, which are covered by hairlike structures, against the…
Read More
The masked birch caterpillar (Drepana arcuata) produces vibratory signals in order to defend its territory against intruders of the same species; it produces the vibrations by drumming its mandibles on the leaf surface and by scratching its legs, which are covered by hairlike structures, against the…
Read More