Scorpions in Arizona
About 40-60 species occur in Arizona, although many are undescribed. The bark scorpion (Centruroides exilicauda) is the only species in Arizona of medical importance.
ARIZONA BARK SCORPION
In the USA the bark scorpion is found in southeastern California, Arizona,
Nevada, southern Utah, and southwestern New Mexico. It is also found
throughout the Baja Peninsula and western Sonora in Mexico. The typical
"bark" or "crevice" scorpion is encountered in a
variety of situations. It is most commonly found under rocks, logs,
tree bark, and other surface objects. The bark scorpion (1-3 inches
in length) is the most commonly encountered house scorpion. They are
common throughout many habitats but almost always in rocky areas.
Most scorpion species are solitary in nature. The exception to this
is bark scorpions, which may over-winter in aggregates of 20-30. The
bark scorpion is also one of relatively few species that are able climbers.
The venom of the bark scorpion may produce severe pain (but rarely swelling)
at the site of the sting, numbness, frothing at the mouth, difficulties
in breathing (including respiratory paralysis), muscle twitching, and
convulsions. Death is rare, especially in more recent times. Antivenin
is available for severe cases. Certain people, however, may be allergic
to the venom and can experience life-threatening side effects when stung
(as occurs with bee stings).
DESERT HAIRY SCORPION
Another species found in Arizona is the desert hairy scorpion (Hadrurus
arizonensis). This species is twice as large as the bark scorpion at
maturity (up to 5 inches long). They are often found in low sandy areas
throughout the state.
Desert hairy scorpions usually eat insects, spiders, centipedes, small
vertebrates and other scorpions.
Another genus frequently found is the devil or stripe-tailed scorpion group (Vaejovis spp.). There are several Vaejovid species found in Arizona. They are intermediate in size (1-2 inches in length) and are more robust than bark scorpions.
The stripe-tailed scorpion is typically found under many surface objects (including sleeping bags, shoes, etc.) where it digs a short burrow or "scrape" for protection. This species is normally an obligate burrower, digging burrows about one meter deep in gravel soils.
Management of Scorpions
High numbers of scorpions can become a problem under some circumstances. If a reduced population is desirable several steps can be taken.
Scorpions are difficult to control with insecticides alone. Therefore, the first control strategy is to modify the area surrounding a house or structure:
• Remove all harborages such as: trash, logs, boards, stones, bricks and other objects from around the building.
• Keep grass closely mowed near the home. Prune bushes and overhanging tree branches away from the structure. Tree branches can provide a path to the roof for scorpions. Minimize low growing ground cover vegetation.
• Store garbage containers in a frame that allows them to rest above ground level.
• Never bring firewood inside the building unless it is placed directly on the fire.
• Install weather-stripping around loose fitting doors and windows.
• Plug weep holes in brick veneer with steel wool, pieces of nylon scouring pad or small squares of screen wire.
• Caulk around roof eaves, pipes and any other cracks into the building.
• Keep window screens in good repair. Make sure they fit tightly in the window frame.
• By managing the scorpion food source, you will manage the scorpion population