Insects of the American River Parkway

Tarantulas comprise a group of often hairy and very large arachnids belonging to the Theraphosidae family of spiders, of which approximately 900 species have been identified. This article only describes members of Theraphosidae, although some other members of the same suborder are commonly referred to as "tarantulas". Most species of tarantulas are not dangerous to humans, and some species have become popular in the exotic pet trade. less ↑

Latrodectus Hesperus, the western black widow spider or western widow, is a venomous spider species found in western regions of North America. The female's body is 14–16 mm (1/2 in) in length and is black, often with an hourglass-shaped red mark on the lower abdomen. This "hourglass" mark can be yellow, and on rare occasions, white. The male of the species is around half this length and generally a tan color with lighter striping on the... less ↑

Cheiracanthium inclusum, alternately known as the black-footed yellow sac spider or the American yellow sac spider (in order to distinguish it from its European cousin C. punctorium), was formerly classified as a true sac spider (of the family Clubionidae), but now belongs to the long-legged sac spiders (family Miturgidae). It is a rather small pale yellow species that is indigenous to the Americas and can be found living in the foliage of forests and gardens but... less ↑

Linyphiidae is a family of very small spiders, including more than 4,300 described species in 578 genera worldwide. This makes Linyphiidae the second largest family of spiders after the Salticidae. New species are still being discovered throughout the world, and the family is poorly known. Because of the difficulty in identifying such tiny spiders, there are regular changes in taxonomy as species are combined or divided. less ↑

Wolf spiders are members of the family Lycosidae, from the Ancient Greek word "λύκος" meaning "wolf". They are robust and agile hunters with excellent eyesight. They live mostly solitary lives and hunt alone. Some are opportunistic hunters pouncing upon prey as they find it or even chasing it over short distances. Some will wait for passing prey in or near the mouth of a burrow. less ↑

The jumping spider family (Salticidae) contains more than 500 described genera and about 5,000 described species, making it the largest family of spiders with about 13% of all species. Jumping spiders have some of the best vision among arthropods and use it in courtship, hunting, and navigation. Though they normally move quietly and fairly slowly, most species are capable of very agile jumps, notably when hunting, but sometimes in response to sudden threats. Both their book... less ↑

Ammotrechidae are a family of solifuges distributed in the Americas and the Caribbean Islands. They include 22 described genera and at least 83 species. Members of this family can be distinguished from members of other families by the absence of claws on tarsi of leg I, tarsal segmentation 1-2-2-(2-4), pedipalps with pairs of lateroventral spines, and by males having an immovable flagellum on the mesal face of each chelicerum. The propeltidium of Ammotrechidae is recurved. less ↑