About Holocnemus pluchei (Scopoli, 1763)
Male and female Holocnemus pluchei are roughly similar in size: males measure 5–7 mm in body length, while females measure 5–7.5 mm. Members of this species have long, fragile legs, with distinct black and white rings around the leg joints. Immature H. pluchei closely resemble adult individuals of the species. Females of this species have swollen pedipalps, which look very similar to the pedipalps of a male before the male completes his final molt. Females also have a projection on the sternum; researchers think this projection plays an important role in mate selection, by increasing the female's level of control over copulation. Both male and female H. pluchei have stridulatory organs, which work when the pedipalp rubs against the chelicera. No morphological differences between the sexes have been observed in these organs. The marbled cellar spider, H. pluchei, is native to the Mediterranean region of Europe and Northern Africa. It may have been introduced to the North Pacific region of the United States in the mid-1900s. It is now very common in Southern California, where it is classified as an urban pest. The species is also found in the southern parts of Western Australia. H. pluchei builds its webs under rocks, inside basements, and on the exterior or interior walls of buildings. This species primarily lives in warm terrain, favoring spaces under rocks, caves, and basement areas.
