Tinea pellionella (Linnaeus, 1758)

Casemaking clothes moth

A clothes moth whose larvae carry a silken case as they feed on fabrics.

Order: Lepidoptera
Family: Tineidae
Group: Moths
Ontario status: Established, indoor fabric pest provincewide

Why it matters

Damages wool, fur, upholstery and carpets; the portable case lets larvae wander and spread damage across garments.

Origin

Old World in origin; spread worldwide with the trade in wool and furs.

Behavior

The larva builds itself a portable silken case, open at both ends, and carries it like a sleeping bag, enlarging it as it grows. It feeds with its head poking out and retreats inside when disturbed.

Living conditions

Same dark, undisturbed places as the webbing clothes moth, closets, storage, under rugs. Larvae eat wool, fur, feathers and silk.

Signs of presence

Tiny silken cases (~10 mm) resembling grains of rice on fabric or walls
Holes in woolens and furs
Larvae retreating into cases when disturbed
Mottled gray-brown moths in closets

Weaknesses

Only larvae damage fabric; adults don't feed
Needs animal fibers, synthetics are safe
The carried case makes larvae easy to spot once you know the sign
Heat and prolonged freezing kill all stages

Myths and facts

Myth Those little cases are the eggs.
Reality The case is the larva's portable shelter, the feeding stage itself, not eggs.
Myth Mothballs protect everything.
Reality They only work in sealed containers at full concentration; airy closets get no protection.

Research notes

Morphology

Adults 6-8 mm body, wingspan 12-16 mm; mottled gray-brown forewings with indistinct darker spots. Larva ~10 mm, cream with a brown head, living inside a portable silken case open at both ends, the diagnostic feature.

Diagnostics

Confirm by the carried case (vs. webbing tubes of Tineola) plus mottled adult wings.

Easily confused with

Webbing clothes moth, Tineola bisselliella Larva spins stationary webbing, no portable case; adult uniformly buff, not mottled.

Life cycle

Adult: Lives 2-4 weeks; does not feed.
Egg: Laid on keratin; hatch in ~1-2 weeks.
Egg to adult: ~2-4 months at room temperature; longer when cool
Generations per year: 2-3 indoors per year
Nymph or larva: Feeds for 1-3 months (up to a year when cool), enlarging its case as it grows; pupates inside the case.

Development

Complete metamorphosis: egg → larva (case-bearing) → pupa (inside case) → adult.

Reproduction

Females lay ~40-100 eggs.

Distribution

Global: Cosmopolitan indoors
Native range: Old World (probable)
Ontario: Established, indoor fabric pest provincewide

Ecology

Keratin feeder like Tineola; the portable case is predator protection that also enables dispersal between garments.

Resistance

Unknown.

IPM implications

The case is both the diagnostic sign and the monitoring target, cases on walls and ceilings reveal dispersal routes. As with Tineola, control logic is keratin exclusion plus finding the undisturbed breeding material.

Chemical ecology

Sex pheromone monitoring exists; case silk is the larva's engineered microhabitat.

Genetics and DNA

No reference genome published as of 2026

Taxonomy

Order Lepidoptera, family Tineidae. Described by Linnaeus, 1758.

Open questions

Case silk composition and its protective properties.

References

Ebeling, W. Urban Entomology, UC Riverside
Mallis Handbook of Pest Control