Yellow Sac Spider

Learn About the Yellow Sac Spider

The yellow (golden) sac spiders, genus Cheiracanthium are members of the spider family Clubionidae (sac spiders): Members of this family build a sack-like, silken tube in foliage or under bark or stones as their lair. In nature Cheiracanthium species are usually found in foliage, but some species are found inside houses and around other human developments. These spiders are relatively small (10 mm body length), and are yellowish in color; they are difficult to distinguish from one another, and species identification requires examination by an arachnologist.

• Yellow sac spiders are among the least known clinically significant spiders, but they are indeed capable of causing a painful bite with development of a necrotic lesion (not as severe as the brown recluse or hobo), and can sometimes produce systemic effects as well. They are very prone to bite defensively (more so than any other significantly venomous U.S. spider), and some bites in humans have occurred in unusual places, such as in automobiles and swimming pools. It is likely that many U.S. cases of necrotic arachnidism ascribed to the brown recluse spider outside of its natural range, are actually yellow sac spider bites.