Redback Jumping Spider

Description:

From Wikipedia: The red-backed jumping spider (Phidippus johnsoni) is one of the largest and most commonly encountered jumping spiders of western North America. It is not to be confused with the unrelated and highly venomous redback spider (Latrodectus hasselti). When threatened, the redbacked jumping spider can inflict a painful bite in self defense, but with no serious medical consequences. Adults tend to be about a centimeter in length. Both sexes have a bright red abdomen; the female has in addition a black central stripe. The chelicerae of both sexes are of a shining teal color. The rest of the body is mostly black. It is one of the species of jumping spiders which are mimics of mutillid wasps in the genus Dasymutilla (commonly known as "velvet ants"); several species of these wasps are similar in size and coloration, and possess a very painful sting.

Habitat:

The distribution of P. johnsoni is bounded by the Great Plains, the Pacific Ocean, northern Mexico and southern Canada. It occurs from sea level to tree line, occupying relatively dry habitats such as coastal dunes or oak woodlands. Between two and thirty redback jumping spiders per 1,000 m² were found during a study in 1976.