Pholcus phalangioides, commonly known as daddy long-legsspider or longbodied cellar spider, is a spider of the family Pholcidae. It is also known as the skull spider due its cephalothorax resembling a human skull. Females have a body length of about 8 mm and males are slightly smaller. The length of its legs are about 5 or 6 times the length of its body. Pholcus phalangioides has a habit of living on the ceilings of rooms, caves, garages or cellars. This spider species is considered beneficial in parts of the world because it kills and eats other spiders, including dangerous species such as hobo and redback spiders. This is the only spider species described by the Swiss entomologistJohann Kaspar Füssli, who first recorded it for science in 1775.
Habitat
Originally a species restricted to warmer parts of the westPalearctic, through the help of humans this synanthrope now occurs throughout a large part of the world. It is unable to survive in cold weather, and consequently it is restricted to houses in some parts of its range.
Behaviour
Pholcus phalangioides is not considered aggressive, its first line of defense being to shake its web violently when disturbed as a mechanism against predators. It can easily catch and eat other spiders, mosquitoes and other insects, and woodlice. When food is scarce, it will prey on its own kind. Peak breeding in this species occurs between June and September. The female holds the eggs in her pedipalps. Spiderlings are transparent with short legs, and change their skin about 5 or 6 times as they mature. P. phalangioides has been recorded invading foreign webs and eating the host spiders.
Venom
There is a common misconception that Pholcidae are the most venomous spiders in the world, but are harmless to humans because their fangs cannot penetrate human skin. Both of these claims have been proved untrue. Recent research has shown that pholcid venom has a relatively weak effect on insects. In the MythBustersepisode "Daddy Long-Legs" it was shown that the spider's fangs could penetrate human skin, but that only a very mild burning feeling was felt for a few seconds.
