Furcula occidentalis
(Lintner, 1878)
Western Furcula Moth, Double-lined Furcula, Willow Kitten
occidentalis is a known by several including western furcula moth, double-lined furcula, and willow kitten. The exhibits a broad transcontinental distribution across North America, from the Yukon to the Atlantic coast. are active from spring through summer with one to two annually. The feed primarily on willow (Salix) species and occasionally on poplar (Populus), giving rise to the 'willow kitten' common name.



Pronunciation
How to pronounce Furcula occidentalis: /fʊˈrkuː.la ɔk.sɪˈdɛn.tə.lɪs/
These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.
Identification
Distinguished from similar by the combination of two distinct dark transverse on the and its broad North distribution. The specific epithet 'occidentalis' historically distinguished it from eastern relatives, though the species now spans the continent. Larval identification relies on the characteristic forked structure combined with association with Salix/Populus. may be separated from other notodontids by pattern and geographic occurrence.
Images
Appearance
Wingspan 32–45 mm. have with two distinct dark transverse , contributing to the 'double-lined' . The overall pattern and coloration are characteristic of the , with muted tones typical of moths. possess the distinctive forked or 'furcula' structure that gives the genus its name, and exhibit the kitten-like appearance referenced in the common name 'willow kitten'.
Habitat
Associated with riparian and wetland supporting willow and poplar plants. Occupies diverse environments from forests to temperate deciduous woodlands, contingent on presence of larval .
Distribution
Transcontinental North America: southern Yukon and British Columbia east to Nova Scotia; south to Maryland; west to Utah and Oregon. Presence confirmed in Canadian provinces including Alberta, Manitoba, and Saskatchewan, and US states including Vermont.
Seasonality
active April to August. One to two per year depending on latitude and local conditions. present June to September. Overwinters as .
Diet
feed on Salix (willow) ; occasionally observed on Populus (poplar) species. Specific Salix species not documented in available sources.
Host Associations
- Salix - larval primary
- Populus - larval occasional
Life Cycle
with one to two annually. laid on plants. feed June to September, developing through . occurs in soil or leaf litter; overwinters in pupal stage. emerge spring through summer.
Behavior
are foliage feeders on plants. Pupal allows in temperate climates. period spans spring and summer months.
Ecological Role
in riparian and woodland ; contributes to through leaf consumption. Serves as for . No documented specialized .
Human Relevance
No significant economic impact documented. Not considered a . 'willow kitten' reflects cultural recognition of larval appearance. Occasional presence in urban and suburban areas with suitable plants.
Similar Taxa
- Furcula cinereaSimilar larval and use on Salix/Populus; distinguished by distribution and pattern
- Furcula borealisOverlapping range in eastern North America; distinguished by pattern details and
More Details
Nomenclatural history
Described by Lintner in 1878. The specific epithet 'occidentalis' reflects the ' original description from western North America, though subsequent recognition revealed a much broader transcontinental distribution.
Sources and further reading
- BugGuide
- Wikipedia
- GBIF taxonomy match
- iNaturalist taxon
- NCBI Taxonomy
- Catalogue of Life
- Lakin Grasshopper
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