Philodromus vulgaris
(Hentz, 1847)
longlegged crab spider
Philodromus vulgaris is a running crab spider in the Philodromidae, commonly known as the longlegged crab spider. It is a small to medium-sized spider found across North America, including the United States and Canada. The belongs to a known for its flattened body form and laterigrade leg orientation, adaptations that facilitate sideways movement and hunting on flat surfaces. It is one of numerous Philodromus species documented in the region, though specific biological details remain limited in published literature.
Pronunciation
How to pronounce Philodromus vulgaris: /ˌfɪloʊˈdroʊməs vʊlˈɡɛərɪs/
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Identification
Philodromus vulgaris can be distinguished from other running crab spiders by its specific genitalic , which requires microscopic examination for definitive identification. Externally, it resembles other small Philodromus , particularly P. rufus and P. aureolus, with which it shares general body form and coloration. The species tends to have a more northern distribution than many . Accurate identification typically requires examination of the male or female by a arachnologist.
Images
Habitat
Found in wooded and forested , particularly on tree bark, woody debris, and under loose bark. The flattened body form is an to living in narrow crevices and on flat vertical or horizontal surfaces. Has been documented in human dwellings, including bathrooms, where wandering individuals may become trapped in sinks and tubs.
Distribution
North America: United States and Canada. Specific records include Alberta, Canada and various localities across the contiguous United States.
Behavior
Active hunters that do not build webs to capture prey. Uses laterigrade leg movement to pursue and ambush small arthropods on bark and other flat surfaces. Wandering can lead individuals into human structures, where they may be found in sinks, bathtubs, and other moist environments. When trapped in smooth-walled containers such as bathtubs, individuals have difficulty escaping due to lack of traction.
Ecological Role
of small arthropods in forest and woodland . Contributes to regulation of insect in bark-dwelling .
Human Relevance
Occasionally enters human dwellings, particularly bathrooms, where it may cause mild alarm due to unexpected encounters. Not medically significant; bites are rare and not considered dangerous to humans. Sometimes mistaken for more dangerous spiders due to general crab spider appearance.
Similar Taxa
- Philodromus rufusSimilar small size, flattened body form, and bark-dwelling habits; requires genitalic examination for separation
- Philodromus aureolusOverlapping coloration and preferences; distinguished by subtle morphological differences and geographic distribution patterns
- Other Philodromus speciesMany share general running crab spider ; reliable identification requires examination of reproductive structures
More Details
Taxonomic note
Philodromus vulgaris was described by Nicholas Marcellus Hentz in 1847. The specific epithet 'vulgaris' refers to its common or widespread occurrence, not any undesirable quality. The has been documented in entomological and arachnological surveys, but detailed natural history studies specific to this species remain limited in the accessible literature.
Etymology
The name Philodromus derives from Greek 'philos' (loving) and 'dromos' (running), referring to the active running of these spiders rather than web-building. The name vulgaris is Latin for 'common' or 'widespread'.