The Arizona bark scorpion (Centruroides sculpturatus) is the most venomous scorpion in North America. Accurate identification of this species is important for safety. It is found in the southwestern United States and parts of Mexico.
Distinctive Physical Characteristics
The Arizona bark scorpion is relatively small, with adult males typically reaching up to 8 centimeters (3.1 inches) in body length, while females are slightly smaller, around 7 centimeters (2.8 inches). Their coloration usually ranges from light brown, tan, or yellowish. Some individuals found at higher elevations may exhibit faint stripes.
A prominent feature is its slender body, particularly the tail (metasoma), which appears thin or thread-like compared to other scorpions. The pincers (pedipalps) are also notably small and slender. The tail has five segments, with the stinger at the tip, and a tiny bump, or “subaculear tooth,” may be visible just beneath the stinger. Their legs are slender and generally match the body color.
Behavioral and Habitat Indicators
Arizona bark scorpions are commonly found in the Sonoran Desert. They prefer natural habitats such as rocky areas, hiding under rocks, logs, tree bark, and in crevices. In residential environments, they frequently seek shelter in wall cracks, under debris, and inside homes, often near moisture sources.
These scorpions are primarily nocturnal. They uniquely climb vertical surfaces like walls, trees, and drapes. When at rest, the bark scorpion often holds its tail curled to its side or flat and parallel to the surface. Their movement is typically quick and darting, especially when disturbed.
Common Misidentifications and Key Differences
Distinguishing the Arizona bark scorpion from other scorpions in the same region can be challenging due to superficial similarities. The Arizona hairy scorpion (Hadrurus arizonensis) is often mistaken for it, but it is considerably larger, growing up to 8 inches, and has a robust, hairy body.
Its tail and pincers are also much thicker compared to the bark scorpion’s delicate build. Another common look-alike is the Stripe-tailed scorpion (Paravaejovis spinigerus). While also yellowish, the Stripe-tailed scorpion has a noticeably thicker tail with distinct dark stripes along its dorsal area.
Its pincers are also larger and more robust than those of the bark scorpion. Unlike the climbing bark scorpion, both the Arizona hairy scorpion and the Stripe-tailed scorpion are primarily ground dwellers.