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Objective

You will learn to identify the four common types of scorpions found in Arizona. You will learn details about each of their characteristics, and some common misinformation.

Introduction

Scorpions thrive in the type of climate that Arizona provides and tend to be found mostly in the southern parts of the state. Four species of scorpions are commonly found in Arizona’s Sonoran Desert. They are the Bark scorpion, the Striped Tail or Devil’s scorpion, the Giant or Desert Hairy scorpion, and the Yellow Ground Scorpion. Although more than 30 species of scorpions are found in Arizona, only the sting of the Bark scorpion is considered to be truly life threatening.

Scorpion Season:

  • March to April – As temperatures warm up, scorpions and other pests become more active.
  • May to June – When the temperatures get hot and humid, scorpions tend to move more slowly to conserve energy.
  • July to August – This is the time of year when scorpions are at their most active.
  • Winter – scorpions will hibernate in groups of 20 to 30.

Food & Behavior

Most scorpions are nocturnal, where they will ambush their victims. They will often feed on medium to small insects such as cockroaches, crickets, spiders, beetles and other types of insects and have also been known to be cannibalistic.

Scorpion Reproduction

Unlike spiders who lay eggs and wrap them in sacks made of silk, the scorpion is born alive without needing to be externally incubated. The mother scorpion will have around 25 to 35 scorplings during the summer months, which will stay next to her and mainly on her back for around 3 weeks. After this time period, they will have their first mold and begin their independent lives. Whenever a female scorpion gives birth, they have to remain immobile and they will not show hostile behavior towards their offspring who are defenseless. The life expectancy of this scorpion is around 6 years.

Threats

The main predators of the scorpion are grasshoppers, owls, mice, bats, shrews, tarantulas, lizards and centipedes.

Scorpion Stinger and Venom Bulb

Misinformation

There’s a lot of misinformation about scorpions. First, the venom found in their stingers isn’t always harmful to humans. Their venom is meant for prey, and human beings are a little too large to make for good prey. This means that deaths resulting from scorpion stings happen extremely rarely.

Scorpion Anatomy

  • Scorpions have some of the same characteristics as a lobster or crab. Their pinchers are one of the similar features.
  • Scorpions however are more closely related to spiders.  They share common characteristics, such as having eight legs. Unlike insects that have six legs. This means that scorpions are not insects. However, insects are their favorite food.

Common Types of Scorpions in Arizona

The following are four of the more common types of scorpions in Arizona and how you can tell them apart: (Remember: the smaller the size the more dangerous it is!)

1 – Bark Scorpion

  • The Arizona bark scorpion is one of the more commonly known scorpions in Arizona. It’s easy to tell them apart from other types of scorpions due to their long, slender metasomas (the tail that holds the stinger), fingers and arms, as well as its yellowish-tan color, although in higher elevations it is often striped.
  • The size of a Bark Scorpion ranges between 2.7 and 3.1 inches long and the males are often times larger than their female counterparts.
  • When its tail is at rest, it is held coiled to its side. It will lay it’s tail down parallel to the surface it is on but still curled up while waiting for prey to come along.
  • 2 dark eyes on top of head, above 3 pair of lateral eyes.
  • Arizona bark scorpions are commonly found in the rocky desert areas, although they are the type of scorpion that homeowners will typically find inside their Arizona homes. They can be found in and around tree bark as well, which is where they get their name.
  • Bark scorpions display Negative Geotaxis, that is they often orient themselves upside down, people are often stung by them as they pick up an object and press against a scorpion clinging to the underside.
  • These scorpions are also some of the more venomous scorpions found in the state. Being stung by an Arizona bark scorpion can result in painful swelling along with breathing difficulties and muscle spasms.
  • If you’ve been stung by an Arizona bark scorpion, you should seek medical attention right away, even though they are typically not life threatening.
Bark Scorpion Features
Bark Scorpion and Coiled Tail

2 – Stripetail Scorpion

  • The Arizona stripetail scorpion is the most common type of scorpion found in Arizona. It boasts a lustrous and robust metasoma and a striped dorsal area that ends with a spinoid granule.
  • The Arizona stripetail scorpion is yellowish in color and features dark stripes on its dorsal area. These types of scorpions are typically less than three inches long, although females are usually bigger than males.
  • Most Arizona stripetail scorpions live beneath rocks, although like Arizona bark scorpions, they do commonly find themselves inside of Arizona homes as well.
Stripetail Scorpion
Details of the Stripetail

3 – Giant Hairy Scorpion

  • The Arizona giant hairy scorpion has the distinction of being the largest scorpion in the United States. If their size wasn’t enough to help identify them, the fact that they have hairy metasomas and pedipalps probably is.
  • They are the only American scorpions to have such dense hair coverage. Their colors are also a unique trait — while their appendages are yellowish in color, their dorsal areas are usually quite dark.
  • The Arizona giant hairy scorpion is most commonly found in saguaro forests and feeds on centipedes, spiders, and other scorpions.
Desert (Giant) Hairy Scorpion
Notice the Tail Position

4 – Yellow Ground Scorpion

  • The Yellow Ground Scorpion is very similar in appearance to the Arizona Bark Scorpion and is often misidentified as such. It has slender hands and fingers, just like the bark scorpion, and exhibits a yellowish color with a granular body texture.
  • The biggest difference in appearance between the Yellow Ground Scorpion and the Arizona Bark Scorpion is the fact that their first two metasomal segments are as wide as they are long or even wider. These nocturnal scorpions are more commonly found in southeastern Arizona.
Yellow Ground Scorpian

Daytime Identification Test

Can you correctly identify these four scorpions now? Give it a try…