The bold jumping spider is one of the most common jumping spiders in North America. They are found in forests, prairies, farmland, yards, homes and even in our cars. But don’t worry, they are not dangerous. They are very rarely known to bite, and if they do their venom will only annoy your skin.
This species is known by a few other names: bold jumper, daring jumping spider and its scientific name, Phidippus audax. “Audax” is from the word audacity, which means willingness to take bold risks. These spiders are named for their bravery and fearlessness in attacking prey larger than them. They are also capable of jumping four times their body length, which ranges from1/4 of an inch to 5/8 of an inch. The females are larger than the males.
This spider is easy to identify. For one thing, like most jumping spiders, they are very hairy. Bold jumpers are mostly black with white stripes on their legs, a few white markings on their heads and a white triangle plus two small white dots on their abdomens. Their chelicerae (spider mouthparts) are a metallic green color that is much more striking on males.
These spiders are daytime hunters, and they depend on their sharp vision to stalk their prey. Like most spiders, jumping spiders have eight eyes. They are arranged in a shape almost like a semi-circle, and each pair is a different size. Their eye arrangement is a distinct feature of jumping spiders, and it is helpful in distinguishing them from other spider species.
They are stealthy hunters, sneaking up on their prey and pouncing. The male and female spiders have different strategies for hunting, depending on the type of prey they are after.
Jumping spiders do not spin webs, but they do drop draglines. That means that before jumping they secure a strand of silk to the surface they are on. This way, if they jump and it does not go as planned they are still attached to the surface and do not fall. They also use silk to make a retreat or line the inside of a crevice they find. They use this space to bring back their food to eat as well as for a safe place to sleep at night. Predators of jumping spiders include birds, lizards and dragonflies.
These spiders breed from mid-spring to early summer. Males have an elaborate courtship display to attract females. They move their front legs, chelicerae and pedipalps (spider “arms”) to impress a female. Females produce six to eight egg sacs in one season, and each contains between 30 and 170 eggs. The female will guard the sac until the baby spiders hatch.
Spiders molt as they grow. They crawl out of their skin, similar to snakes. Bold jumping spider will pause this process as juveniles and become inactive during winter months. In the springtime they pick up where they left off. It takes about five or six molts before they are fully grown adults and ready to breed.
Want to learn more about spiders? The Forest Preserve District of Will County has several opportunities coming up:
Four Rivers Environmental Education Center in Channahon will host a Spider Hike at 7 p.m. Tuesday, September 15.
Isle a la Cache Museum in Romeoville will host a Spider Eye Shine Hike at 7 p.m. Friday, October 2.
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