Bold jumper

Description

Bold jumper is an extremely common jumping spider in eastern United States. It is a medium-sized spider but a very large jumping spider. It is highly variable in appearance.

The female body is ⅛″ to ¾″ long, not including the legs. The male is smaller than the female, ⅛″ to ⅝″ long. The front part of the body (cephalothorax) and abdomen are black with white spots and are covered with short white hairs giving them a fuzzy appearance. The male is more contrastingly marked than the female.

The cephalothorax is massive, high, and longer than wide. Its sides are rounded.

The abdomen is widest in the middle and tapered to the end (posterior). It has 4 pairs of white spots and 4 pairs of squarish matte black spots. The first (anterior) pair of white spots is sometimes absent or inconspicuous. The second pair is usually, but not always, fused into a large central spot. The third pair are elongated, appearing as short stripes. The fourth (posterior) pair are much smaller and sometimes inconspicuous. The black spots are covered with short black hairs, the white spots with white hairs. On juveniles the light spots are often orangish-red.

There are four pairs of eyes arranged in three rows. The first row of of four eyes is recurved. The middle pair of these is by far the largest of all of the eyes. The second row of two eyes is closer to the first row than it is to the third. The second and third rows form a square. The jaws (chelicerae) are small. The basal parts of the chelicerae are iridescent green or blue.

The legs are short. On the male they are boldly striped white and black. On the female they are faintly striped.

Size

Female Body Length: ⅛″ to ¾″

Male Body Length: ⅛″ to ⅝″

Web

No web

Similar Species

Regal jumper (Phidippus regius) lacks matte black spots on the abdomen. It occurs in southeastern United States, not in Minnesota.

Habitat

Old fields, prairies, open woodlands, backyards, gardens, and human houses

Ecology

Season

Spring to fall

Behavior

Bold jumper hunts during the day by sneaking up and pouncing on its prey. It releases silk while jumping as a drag line to prevent falling. It does not hunt at night.

It will bite if molested but is usually too quick and wary to be caught. It can jump 10 to 50 times its body length.

Life Cycle

Mating takes place in late spring or early summer. When courting, a male will wave its forelegs and palps, showing off his colorful chelicerae. After mating the female produces up to 6 sacs of 30 to 170 eggs each during the summer. She lays these egg sacs under the bark of logs, creates a silk shelter to protect the hatchlings, and stands guard until the hatchlings disperse. Juveniles overwinter in a silk cocoon under bark or some other protected space. Adults mature in the spring.

Food

Insects, spiders, and possibly other small invertebrates and vertebrates