RETURN TO ARCHIVES


Wild Thing - Shirlene Chadick
January 2004


Phidippus audax
Photo from Troy's Photo Gallery © 1998-2003 Troy Bartlett


Whether you call them "Daring Jumping Spider" or "Black Jumping Spider" - you'll see them in your garden shed, lurking around your porch, and most often trapped and starved or starving between your window and screen.

Approximately 300 species of the Jumping Spider family Salticidae reside in North America, and Phidippus audax, the Daring Jumping Spider, is most common.


Appearance & Size
The Daring Jumping Spider has a stocky, hairy body. Adults' abdomens are black with white spots, and juveniles' abdominal spots are orange. The first pair of legs have black and white stripes and the chelicerae (jaws) are iridescent green. The male is up to 1/2 inch long, and the female is up to 5/8 inch long.


Vision
Daring Jumping Spiders have vision far superior to most other invertebrates, and can identify prey, predators, and potential mates from up to 12" away. Their eye arrangement is designed for predation. Four big eyes on the face (for sharp vision) and four smaller eyes on top of the head (for peripheral vision), distinguish Salticidae from other spiders.

These spiders have dichromic vision (that's "colorblind" to you and me) with spectral sensitivities in the green and ultraviolet range (ultraviolet vision being common in the insect and arachnid world).

When a Daring Jumping Spider spots a potential victim, they observe the prey's position, then move a short distance, and observe the prey's position again. Having taken two visual coordinates, they jump.


Behavior
The Daring Jumping Spider hunts during the day (diurnal) and retreats to it's resting sac at night. Jumping Spiders typically pursue and leap upon their prey; jumping great distances that can measure up to 40 times their body length. Even though they do not spin webs, they use a silk dragline as a safety line before jumping. They stick the dragline to an object, leap, and if they miss their prey, can recover by crawling back up the dragline. If the jump hits a prey target, the spider can hang suspended in the air, not allowing the prey to secure a foothold for leverage until it has been immobilized by injected venom.

Their ability to jump great distances is a good defense as well as offense, because they can readily escape danger by quickly jumping away. They are also capable of moving sideways and backwards with great agility and speed.

Daring Jumping Spiders are not harmful to humans, and will make every attempt to get out of your way. If provoked or cornered, they will go into characteristic threat posture with first legs outstretched, and iridescent chelicerae exposed. If you continue bullying him or her, at this point it most often decides to leap and bite. This actually is a lot less fun than it sounds.

Jumping Spiders usually make resting sacs with two openings at opposite ends. During the day, a spider may open one or both ends of the sac and stay inside, looking out. The openings of the sac are closed at night when the spider sleeps.

The female also uses silk to make an egg sac and tends to it until the spiderlings hatch and disperse. To disperse, the young spiderlings, "balloon" by riding air currents carried by extended strands of silk.

Daring Jumping Spiders are aggressive carnivores, eating insect larvae, insects and other spiders. The juvenile spiders feed on insect eggs and insects in the smaller larval stages.

Despite their formidable appearance, Daring Jumping Spiders are a very beneficial resident in your yard, in your garage and on your porch - they're pretty much everywhere!



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