Thyatiridae - the caterpillars of thyatirids. External leaf feeders but are found in loosely tied leaves, occurring primarily on broadleaf plants. Caterpillars may be 40 mm in length when full grown. The adults are night-flying moths. Typically external leaf feeders but often in a rolled leaf.
Many species are leaf miners as early instars, occurring on conifers and broadleaf plants.
A full grown caterpillar of a large tortricid may reach 20-25 mm as in Choristoneura rosaceana . The caterpillars move quickly in reverse when disturbed. The adults are night-flying moths.