Joseph Berger, Bugwood.org
Pholcidae—Cellar or Daddylong-legs Spiders
The longbodied cellar spider is the most common of the Pholcidae in the United States. It has extremely long legs and is found in many types of buildings throughout the year. Although these spiders can develop large populations in protected locations, they are not known to be in any way harmful. This spider is commonly found in cellars, warehouses, garages, caves, and other dark, quiet, protected spots.
Pholcus phalangioides female with eggs. Photo by Olaf Leillinger, WikiMedia
The females are from 7 to 8 millimeters and the males 6 millimeters in length. The carapace is very wide. The abdomen is about three times as long as it is wide and cylindrical in shape. The eyes are arranged in two triads of larger, light-colored eyes on the top of the cephalothorax and a pair of dark, small eyes on the front. The color of the carapace and abdomen is a pale tan or yellow with a gray mark in the center of the carapace.
The forelegs of the adult female are about 50 millimeters in length. The webs are an irregular mesh of threads.
Both male and female spiders can be found in heated structures throughout the year. It takes approximately one year for the spiders to mature and they can live for two or more years as adults.
The eggs, which are about 1 millimeter in diameter, are deposited in clusters of twenty-five to sixty and wrapped in a thin layer of silk. The sac is held by the female in her chelicerae as she hangs inverted in her web.
An unusual behavior is that the spiders will rapidly vibrate in a circular fashion in the web if threatened, making it difficult to see them.
These spiders are not known to bite people and are not a medically important species.
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