Philodromidae

Philodromidae is a family of spiders commonly known as philodromid crab spiders or running crab spiders. This family is superficially similar to the "true" crab spiders in the family Thomisidae.

Contents

• Running crab spider philodromidae philodromas on tree trunk
• Philodromid crab spider philodromidae on grassblade
• Genera
• References

However, studies have shown that these families are not as closely related as previously thought. Unlike thomisids, philodromids tend to have few true setae (hairs or spines) on their bodies. They also lack the congruent eye tubercles of some thomisids. The second legs are usually the longer of the four pairs of walking legs and in the genus Ebo this is quite extreme, with the second pair of legs in some species twice as long as the first pair.

The most common genus is Philodromus which, like Ebo is widespread. Other common genera include the elongate grass-dwelling Tibellus and the widespread Thanatus, which includes the widely distributed Holarctic house crab spider Thanatus vulgaris. This species commonly captures flies on and in buildings.

The family contains over 500 species in nearly 30 genera. Most are dull colored- brown, gray, yellowish or mottled, and seldom reach above 10 mm in body length. Most have a leaf-like cardiac mark on the anterior dorsal abdomen. None of the species build webs, but they do use silk for draglines and for egg sacs.