Tinea occidentella
Chambers, 1880
Western Clothes Moth
Tinea occidentella is a keratophagous in the Tineidae, native to coastal California and northern Baja California. Despite its "western ," it does not feed on clothing but instead consumes keratin from mammalian scat and bird of prey pellets. The species is tightly restricted to fog-influenced coastal environments where high humidity allows larvae to obtain water from atmospheric moisture absorbed by their fur and feather diet.
Pronunciation
How to pronounce Tinea occidentella: /ˈtɪniə ˌɒksɪdɛnˈtɛlə/
These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.
Identification
Distinguished from other Tinea by the combination of relatively large forewing size (7–12 mm), dark grey coloration with lighter central forewing region containing a prominent darker fleck, and restriction to coastal fog belt . The "western " is misleading; true clothes moths (Tineola bisselliella, Tinea pellionella) feed on woolens and stored fabrics, whereas T. occidentella feeds only on scat and pellets in natural settings.
Images
Appearance
Forewing length 7–12 mm. Dark grey overall with lighter central region on forewing; a darker spot or fleck is prominent within this lighter area.
Habitat
Coastal areas of high humidity derived from advective fog off the sea. Restricted to moist, mild climates where fog, dew, and morning relative humidity of 99% are common.
Distribution
Pacific coast from San Francisco Bay region through coastal northern Baja California. Virtually restricted to this coastal fog belt; rare or absent in warmer, drier inland areas of its broader geographic region.
Diet
Keratin from fur and feathers in mammalian scat and in pellets of birds of prey. Also reported to develop on bird carcasses.
Life Cycle
Larvae feed upon keratinous materials and require relative humidity >88–99% for normal growth, survival, , and . Larvae do not absorb water vapor directly from the atmosphere and do not drink; instead, they obtain water via atmospheric moisture absorbed by the fur and feathers of their diet.
Behavior
Larvae have been observed to grow normally only when feeding at very high relative humidity upon fur from pellets and scat.
Ecological Role
Keratophagous decomposer; contributes to breakdown of keratinous materials in scat and raptor pellets in coastal .
Human Relevance
None; does not damage clothing or stored goods despite misleading . Not a household pest.
Similar Taxa
- Tinea pellionellaCasemaking clothes moth; true pest of woolens that constructs portable silk case. T. occidentella does not feed on fabrics and is restricted to natural coastal .
- Tineola bisselliellaWebbing clothes moth; major household pest of keratinous fabrics. T. occidentella is not and does not inhabit human dwellings.
Misconceptions
The "western " is a misnomer. This does not eat clothes and is not a household pest. It feeds exclusively on scat and pellets in natural coastal environments.