Philodromus oneida
Levi, 1951
Oneida Running Crab Spider
Philodromus oneida is a of running crab spider in the Philodromidae, first described by Levi in 1951. It is distributed across the United States and Canada, with records from Alberta, British Columbia, and Manitoba in Canada. As a member of the Philodromus, it shares the characteristic laterigrade leg orientation that allows sideways movement, typical of running crab spiders.
Pronunciation
How to pronounce Philodromus oneida: /ˌfaɪloʊˈdroʊməs oʊˈnaɪdə/
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Identification
Philodromus oneida can be distinguished from other running crab spiders by the characteristic laterigrade leg arrangement where the second pair of legs is the longest, oriented horizontally to the body. It can be separated from the superficially similar 'flatties' ( Selenopidae) by its arrangement—Philodromus has eight eyes in two rows rather than six eyes in a single row. It lacks the extremely flattened body and the notched rear edge of the sternum found in Selenops . Identification to species level within Philodromus typically requires examination of reproductive structures.
Habitat
Running crab spiders in the Philodromus are commonly found on vegetation, tree trunks, and the exterior walls of buildings. They are frequently encountered on vertical surfaces at night when they emerge to hunt. They have been documented in indoor environments including bathrooms and showers, where they may become trapped in sinks or tubs due to the smooth surfaces.
Distribution
United States and Canada. Canadian records include Alberta, British Columbia, and Manitoba.
Behavior
Running crab spiders are active hunters that do not build webs to capture prey. They rely on speed and agility to pursue and capture insects. Members of the are frequently observed on vertical surfaces such as walls and tree trunks, and are primarily in their activity patterns. When disturbed, they can move rapidly with a crab-like sideways motion facilitated by their laterigrade leg orientation.
Ecological Role
As , running crab spiders contribute to the control of insect in their . They occupy a mid-level position in , preying on various small arthropods while serving as prey for larger predators including birds and other arthropods.
Human Relevance
Philodromus spiders, including P. oneida, are commonly encountered in and around human dwellings, particularly on exterior walls and occasionally indoors in bathrooms and other humid areas. They are not considered medically significant; bites are rare and not dangerous to healthy humans. Their presence in homes is generally benign and they may contribute to control of small insect pests.
Similar Taxa
- Selenops spp.Both are flattened spiders with laterigrade legs found on vertical surfaces, but Selenops (Selenopidae) has six in one row, a more extremely flattened body, and a notched rear sternum.
- Philodromus other speciesCongeneric share the general body plan and leg arrangement; species-level identification requires examination of genitalia.
- Sparassidae (giant crab spiders)Some huntsman spiders share the crab-like appearance and sideways movement, but are generally larger with different arrangements and body proportions.