Arizona hosts over 30 species of scorpions, but few are truly jet black. Several species are large and dark enough—deep brown or dark olive green—to be perceived as black by residents. The most prominent dark-bodied species is the largest scorpion in North America. Understanding the difference between these darker, less dangerous species and the state’s highly venomous, lighter-colored scorpions is important for safety.
Arizona’s Dark-Colored Scorpion Species
The Giant Desert Hairy Scorpion, Hadrurus arizonensis, can reach lengths of up to 5.5 inches (14 centimeters), making it the largest scorpion found in North America. Its body is typically a dark olive-green or deep brown, giving it a distinctly dark appearance against the desert soil.
The “hairy” name comes from the brown hairs covering its legs and tail, which sense ground vibrations. While the main body is dark, the appendages—legs, pedipalps (pincers), and tail segments—are usually a lighter yellow or tan color, creating a noticeable two-toned look. Juveniles can sometimes be much darker overall before molting, contributing to the idea of a “black” scorpion.
Several smaller species within the Vaejovis genus are also commonly found in Arizona and can appear dark brown or black. These scorpions are generally much smaller, often measuring less than three inches in length. Coloration in all scorpions can vary significantly based on factors like age, recent molting, and the local habitat. This variation means individuals may range from a pale tan to a deep, near-black shade.
Habitat and Activity Patterns
The Giant Desert Hairy Scorpion primarily inhabits arid regions with loose, sandy soil. They are burrowing scorpions, constructing deep burrows that can extend several feet into the ground to escape the intense daytime heat. These burrows provide a cooler, more stable microclimate crucial for desert survival.
Like all scorpions, Hadrurus arizonensis is a nocturnal predator, emerging after sunset to hunt. They use their hairy appendages to detect vibrations in the sand, locating prey such as large insects, spiders, centipedes, and small vertebrates. They are generally only active when nighttime temperatures are consistently above 77 degrees Fahrenheit.
Although they prefer undisturbed desert areas, these scorpions may occasionally wander into residential properties, particularly during the summer monsoon season. They are often found hiding under rocks, logs, or debris near homes, seeking shelter or moisture. Encountering them near or inside a structure usually means the scorpion is seeking refuge from temperature extremes or following a food source, such as crickets or roaches.
Toxicity and Risk Assessment
The Giant Desert Hairy Scorpion’s venom is generally considered to be of low medical significance to healthy adults. Its sting is often described as comparable in pain to a common honeybee sting. The mild venom is used primarily to subdue small prey rather than for defense against larger animals.
A sting from Hadrurus arizonensis typically results in immediate, localized pain, swelling, and sometimes numbness. These symptoms usually resolve on their own without the need for medical treatment. First aid involves cleaning the wound, applying a cool compress, and taking an over-the-counter pain reliever.
The Giant Desert Hairy Scorpion contrasts sharply with the state’s most dangerous species, the Arizona Bark Scorpion (Centruroides sculpturatus). The Bark Scorpion is much smaller, generally two to three inches long, and is a pale, yellowish-tan color. It possesses a neurotoxic venom that is medically significant and can cause severe symptoms, including muscle spasms, pain, tingling, and temporary dysfunction. For a sting from the Bark Scorpion, especially in children or individuals with underlying health conditions, immediate medical attention is necessary.