Dozens of scorpion species inhabit the United States, the majority of which can be found west of the Mississippi River. Most scorpion species dwell far away from urban areas, and are only active at night, making them unlikely to be encountered by humans. In fact, new scorpion species are discovered in the southwest US frequently, and of the 70 to 75 species already documented in the country, experts believe many more species have yet to be discovered. Only four scorpion species are regularly encountered in urban and suburban areas of Arizona, and they are the only scorpion species that are considered pests in the state. These species are named: Hadrurus arizonensis, Centruroides exilicauda (formerly C. sculpturatus), Hoffmannius or Vaejovis coahuila and Vaejovis spinigerus, and they are more commonly known as the “desert hairy scorpion,” the “Arizona bark scorpion,” the “yellow-ground scorpion,” and the “stripe-tailed” or “devil scorpion,” respectively. Of These four species, only the Arizona bark scorpion is considered medically significant.
Due to not being well described in academic literature, many sources make no mention of yellow-ground scorpions as being common pests in Arizona, but these medically harmless scorpions are commonly found within and around homes in the southern half of the state. The desert hairy scorpion stands out among scorpion pests for its relatively massive size, which can exceed 6 inches in length. Although these scorpions are intimidating to look at, their stings are not terribly painful and they are not medically significant, but those with venom allergies may experience distressed breathing, swelling and other symptoms in response to stings.
Yellow-ground scorpions are commonly mistaken for Arizona bark and devil scorpions, as all three species are usually slightly less than three inches in length and are of similar color. However, yellow-ground and devil scorpions are a bit more robust than Arizona bark scorpions, and the back and underside of the tail of the devil scorpion features dark horizontal stripes that both Arizona bark and yellow-ground scorpions lack. Arizona bark and yellow-ground scorpions both have a similar light brown to yellowish body color, and their pincers are longer than those of devil scorpions, but yellow-ground scorpions have a lighter colored back and a bulkier tail than Arizona bark scorpions. It is also important to mention that the Arizona bark scorpion is the only scorpion species that does not burrow and is a capable climber of vertical surfaces. This is why Arizona bark scorpions often congregate on the exterior walls of homes, fall from ceilings, and are commonly found in attics, while the other species are generally found only on the ground, especially within shoes and underneath furniture.
Have you ever put on a shoe that had been occupied by a scorpion?