Brilliant Jumping Spider

Jumping spiders have a distinctive rectangular carapace, and that of female Phidippus clarus average 4.05 millimetres (0.159 in) wide, while the carapaces of males average 3.20 millimeters (0.126 in). They are typically a red/brown coloration, but can sometimes be a lighter yellow or brown with darker markings on their bodies.

Phidippus clarus is found in old fields throughout most of the United States and southern Canada. It has also been recorded from western Mexico. It lives among flowers, often sharing habitats with the small to medium-sized crab spider Misumena vatia, which waits for prey. P. clarus often waits upside down near the top of a plant such as basil leaves, a position which may be useful for detecting prey and then quickly jumping down before the prey can escape. In a 2002 survey of jumping spiders in Minnesota, P. clarus accounted for 52% of the total found.

Almost all jumping spiders are predators, mostly preying on insects, other spiders, and other non-aquatic arthropods. The most-common procedure is sighting the prey, stalking, fastening a silk safety line to the surface, using the two pairs of back legs to jump on the victim, and finally biting the prey. Most jumping spiders walk throughout the day, so that they maximize their chances of a catch. After capturing the prey, P. clarus settles in one spot and does not move again until it has discarded the undigestible hard remains of the prey. If P. clarus has gone without food for a few days, it eats slowly. P. clarus, which is large by the standards of salticids, takes prey up to the size of an adult earwig. In an experiment, when jumping spider were offered as many fruit flies as they could eat within a 4-hour sessions, specimens took 17 flies on average - while one took 41. When the courtship display of wolf spider Schizocosa ocreata combines visual signals with vibrations, P. clarus responds to its wolf spider prey more quickly than when the wolf spider presents only one of the types of signal.