Many people observe spiders that appear largely black with some form of white or lighter spots on their bodies. While this description fits several different species, understanding the specific characteristics of these markings, along with other features, is helpful for accurate identification.
Common Black Spiders with White Markings
One frequently encountered spider that matches this description is the bold jumper, scientifically known as Phidippus audax. This spider typically has a robust, hairy black body with large, iridescent green or blue chelicerae. Its most defining feature is a prominent, often triangular or oval, white or orange spot located on the top of its abdomen. Bold jumpers are active hunters, known for their remarkable jumping ability.
The parson spider, Herpyllus ecclesiasticus, is characterized by its velvety black or dark brown bodies. A distinct white or grayish pattern runs down their back, often described as resembling a “parson’s tie” due to its shape. Unlike the bold jumper, parson spiders are ground dwellers and move very quickly. They are often found scurrying across floors indoors.
While often appearing in shades of brown, some individuals of the spotted orbweaver, Neoscona crucifera, can be quite dark, appearing almost black. These spiders possess a distinctive pattern of white or light-colored spots on their large, rounded abdomen, frequently forming a cross or other geometric shapes. They are known for constructing large, circular webs, particularly at night.
Key Features for Accurate Identification
Beyond color, specific physical attributes and behaviors offer crucial clues for distinguishing spiders. Observing the overall body shape and size can be quite telling; for instance, bold jumpers have a compact, stocky build, while orbweavers possess a larger, more rounded abdomen. The presence or absence of hairiness on the body also provides a visual differentiator.
Examining the legs can also aid identification. Note if the legs are uniformly colored, striped, or spotted, and whether they appear thick and robust or slender. While complex, the arrangement of a spider’s eyes is unique to different families; jumping spiders, for example, have very large, forward-facing eyes that give them excellent vision.
The type of web a spider constructs, or if it builds one at all, is a significant identifier. Spotted orbweavers create elaborate, classic circular webs to catch prey, whereas bold jumpers are active hunters that do not build webs for prey capture. Parson spiders are also non-web-building hunters, preferring to chase down their prey. Observing the spider’s movement, such as jumping, fast running, or remaining still, also contributes to accurate identification.
Understanding Venom and Safety
The venom of the bold jumper is generally considered harmless to humans. Bites are rare and typically occur only if the spider feels threatened or is accidentally pressed against skin. The sensation of a bold jumper bite is often compared to a mild bee sting, resulting in localized pain and slight swelling that resolves quickly.
Parson spider bites are uncommon but can be more painful than a bold jumper’s bite. While the bite may cause localized redness, swelling, and a sharp, stinging sensation, it is not considered medically serious for most individuals. Symptoms usually subside within a day or two without lasting effects.
The spotted orbweaver is not considered a dangerous spider. Its bites are very rare and result in mild, localized discomfort, similar to a mosquito bite or a minor sting. If a spider bite causes severe pain, spreading redness, or other concerning symptoms, seeking medical attention is advisable.
Where to Find Them
Bold jumpers are often found outdoors in sunny areas, including gardens, on walls, and fences, where they actively hunt insects. They may also venture indoors, particularly near windows or doorways, as they are drawn to light and prey. These spiders are diurnal, meaning they are most active during the day.
Parson spiders are commonly encountered indoors, especially in basements, garages, and other undisturbed areas, as they prefer dark, quiet spaces. They are fast-moving ground dwellers, often found under objects like rocks, logs, or leaf litter outdoors. Their nocturnal habits mean they are primarily active at night.
Spotted orbweavers are predominantly found outdoors, constructing their large, circular webs between structures, in garden vegetation, and on porches or eaves. They often build their webs at dusk and may dismantle them by dawn.