Salticidae (jumping spiders) in the order Araneae (spiders)
The bold jumper, or white-spotted jumping spider, is like many other jumping spiders: it is fuzzy, walks with jerky movements, jumps astonishingly long distances, and doesn't build webs.
To identify this species, note the fuzzy, usually black body with spots on the abdomen. The cephalothorax (head) is often larger than the oval abdomen and is a solid black or reddish brown. There are often several white (or orange or reddish) spots on top of the abdomen, a central spot being the largest. The chelicerae (fangs) are iridescent green or blue.
Other Common Names
White-Spotted Jumping Spider
Length (not including legs): ¼ to ¾ inch (females); males are usually less than ½ inch.
Where To Find
Habitat and Conservation
Bold jumpers are often found on broad-leafed plants (such as milkweed) in open areas and on tree trunks, fence posts, and house or barn siding. As with other jumping spiders, silk-spinning is limited to a single "tether" line for safety when exploring or when jumping great distances, and for making cocoon-like retreats to hide in and to protect their eggs.
Insects, especially true bugs and caterpillars, and other spiders appear to be the preferred prey. Jumping spiders have excellent eyesight and are visual predators. The two large eyes facing the front afford good binocular or 3D vision, which helps them jump with accuracy, while the other six eyes are positioned over the head to provide 360-degree views. Once detected, prey is generally pounced upon, grabbed, bitten, and consumed.
Also called the daring jumping spider. The Latinized species name, audax, has the same root as our word "audacious." It is found in much of the United States and southeastern Canada.
Jumping spiders have fascinating courtship dances, where the male waves his forelegs, displays his colorful chelicerae, and drums the ground in rhythmic patterns. These motions and patterns work as a code to signal to females that the is not to be considered food. Eggs are laid in silken cocoons in small crevices throughout the summer. Eggs, young, and adults all can overwinter in spun cocoons under tree bark, in curled-up leaves, and in other tight niches.
Jumping spiders are active, curious creatures, and many people believe they can observe us with their "goggles" as we watch them. Though they can bite if squeezed or otherwise molested, the bite is harmless. Like all spiders, it controls insect populations.
Spiders are little predators that help to control populations of the insects they capture. Being small themselves, they easily fall prey to larger predators such as birds, reptiles, and mammals. Many animals eat their eggs. In winter, many songbirds hunt in fissures of bark and other crevices for hibernating spiders.
About Land Invertebrates in Missouri
Invertebrates are animals without backbones, including earthworms, slugs, snails, and arthropods. Arthropods—invertebrates with “jointed legs” — are a group of invertebrates that includes crayfish, shrimp, millipedes, centipedes, mites, spiders, and insects. There may be as many as 10 million species of insects alive on earth today, and they probably constitute more than 90 percent all animal species.