The striking combination of black and white is a pattern found across many different spider families, often serving as disruptive coloration or a form of warning mimicry. Unlike mammals or birds, a spider’s color alone is rarely enough for positive identification, as the same pattern can appear in species that are not closely related. To accurately identify a black and white spider, it is necessary to observe specific details of its body shape, the exact pattern of its markings, and its unique behavior, such as how it hunts or the type of web it constructs.
The Bold Jumper and Its Family
The most frequent black and white spider encountered is the Bold Jumper, Phidippus audax, a species common across North America. This spider is characterized by a robust, stocky body covered in dense black hairs, giving it a fuzzy appearance. Its most recognizable feature is the presence of distinct white or pale spots on the abdomen, typically a large central spot and two smaller ones toward the rear.
The pair of large, forward-facing eyes gives it excellent vision, a hallmark of the jumping spider family (Salticidae). The Bold Jumper’s chelicerae, or mouthparts, are often iridescent, displaying a metallic blue or green sheen that contrasts sharply with its black body. This spider is an active, diurnal hunter that stalks and pounces on prey without relying on a snare web, instead using a silk dragline as a safety tether when leaping.
Bold Jumpers are frequently found in sunny areas like gardens, fields, open woodlands, and on the exterior of buildings. They are considered harmless to humans, as they are shy and quick to retreat. While they possess venom to subdue prey, their fangs are small. A bite is rare and only occurs if the spider is severely provoked, but it is not considered medically significant.
The Distinctive Zebra Spider
A smaller, equally well-known black and white species is the Zebra Spider, Salticus scenicus, also a member of the jumping spider family. This spider is much smaller than the Bold Jumper, typically ranging from 4 to 7 millimeters in body length. It has a black body overlaid with clear white stripes or bands across its cephalothorax and abdomen, creating a zebra-like pattern.
The Zebra Spider’s smaller size and striped pattern differentiate it from the larger, spotted Bold Jumper. Like its relative, this spider does not build a web for hunting, instead using its superb eyesight to stalk and ambush small insects. It is commonly encountered on vertical, sunlit surfaces such as walls, fences, and windowpanes, where its contrasting coloration may help camouflage it.
Zebra Spiders are active during the day and use their impressive jumping ability to cover distances up to several times their body length to catch prey. This species is found widely across the Northern Hemisphere, including North America, and is harmless to people. The elaborate courtship dances performed by the males, involving waving their pedipalps, are a unique behavioral trait.
Other Spiders With Black and White Markings
Beyond the jumping spiders, black and white patterning appears in other spider groups, requiring observation of their body structure and web type for identification. Certain Crab Spiders (family Thomisidae) exhibit black and white coloration, such as some species within the Xysticus genus, though their coloring is often mottled brown, black, and white. Crab spiders are ambush predators that do not spin webs for capture. They wait on flowers or foliage with their two front pairs of legs extended, which are longer and more robust than the rear pairs. Their ability to walk sideways or backward, reminiscent of a crab, is a distinguishing characteristic.
Orb Weaver spiders (family Araneidae) also feature black and white or black and yellow markings, but they are identified by the large, classic circular webs they build. While many are black and yellow, like the large Argiope species, the undersides of some orb weavers, such as the Hentz Orbweaver (Neoscona crucifera), can be black with two prominent white spots. Their webs can be quite large, often found strung between tall grasses or human structures.
Very few black and white spiders in North America are considered medically significant to humans. The most dangerous spiders in the region, the widow spiders (Latrodectus species) and recluse spiders (Loxosceles species), do not fit the description of a prominently black and white spider. Although some black widows may have small white markings in addition to their red hourglass, the vast majority of black and white spiders encountered are beneficial predators that pose no threat.