Scorpions

New scorpion species found in Santa Catalina Mountains near Tucson

AZCentral.com reports that a new species of scorpion, dubbed Vaejovis brysoni, has been found in the Santa Catalina Mountains. Rich Ayrey, a Flagstaff nurse and former biologist recognized it as a new species. Ayrey has discovered and named five other scorpion species. This particular scorpion was found by University of Washington post-doctoral scholar Robert Bryson, who spotted it in the Santa Catalina Mountains and sent samples to Ayrey and a collaborator to identify last April. The 2-inch-long, mahogany-colored scorpions were found above 6,000 in the mountains during a hiking trip. This discovery is the 10th known mountain scorpion species in Arizona.

See the full story here.

A-new-scorpion

The most dangerous venomous animals of the Southwest

Speckled-rattlesnakeThe southwestern desert has a reputation for venomous critters, but which are most dangerous? I attended a lecture at the Arizona-Sonora Desert Museum given by James W. Cornett, a biologist, author, and emeritus Curator of Natural Science at the Palm Springs Desert Museum. Cornett has studied venomous animals for over 30 years and gave us a list of what he considers the thirteen most dangerous animals.

This list is subjective and includes consideration of the toxicity of the venom, the amount of venom injected, the possibility of an allergic reaction, the abundance of the animal, and the probability you could actually encounter the animal. Here is his list from the least dangerous to most dangerous:

13. Tarantulas. The venom is generally not dangerous to humans and it takes much provocation to get a tarantula to bite you.

12. Centipedes. Some of these can get over 10 inches long (but most are about 5 – to 8 inches) They deliver venom by pinching with its front legs. One death has been attributed to a centipede bite.

11. Velvet ants (actually wasps). These look fuzzy and cute but deliver a very painful bite.

10. Gila monster. These lizards are venomous but it takes some provocation to get them to bite you. (Note: that provocation can be trying to be nice and carrying one off the road so that it doesn’t get run over.)

9. Coral snakes. The coral snakes in the Southwest are generally small. More deaths occur in the East where the snakes are larger.

8. Cone-nosed bugs (aka Kissing bugs). Bites from these bugs can produce an allergic reaction and can transmit Chagas Disease, a chronic and debilitating protozoan infection. Cone-nosed bugs feed on the blood of other animals, mostly rodents.

7. Ants. Swarming ants, by their large numbers can deliver painful bites and cause allergic reactions.

6. Scorpions. Most scorpion stings in the southwest are not dangerous. However, bark scorpion venom is dangerous to humans.

5. Brown (recluse) spiders. The venom is very persistent and causes tissue damage.

4. Wasps.

3. Black Widow spiders. Drop for drop, black widow venom is the most toxic of any animal in the southwest. And now, we are seeing more Brown Widow spiders coming into the area.

2. Rattlesnakes. This venom does great tissue damage and two species, the Tiger rattlesnake and Mohave rattlesnake also have neurotoxic venom. By the way, there are 18 rattlesnake species common to Arizona.

And the most dangerous venomous animal:

1. Africanized Honey Bees. According to Cornett, bees cause more deaths than all the other animals combined.

Besides these animals, Cornett mentioned some snakes that are considered only mildly venomous, some of which are commonly kept as pets. None of these snakes have fangs, but the do have enlarged back teeth and toxic saliva. They need to chew on you for a while to work the venom in. These snakes include the ring-necked snake, black-headed snake, spotted night snake, lyre snake, hog-nosed snake, and the common garter snake.

Cornett related an incident with a hog-nosed snake. This snake was in an exhibit at the Palm Springs Desert Museum. Cornett was attempting to feed it a mouse, but since he handled the mouse, its scent got on Cornett’s hand. The snake bit him on the web between thumb and forefinger and chewed for a while before it could be detached. This mild venom caused swelling and discoloration of Cornett’s hand and arm and produced blisters for about a month. Nobody has antivenom for these snakes.

For more information on venomous animals, see:

Desert Bees and Africanized Bees

Scorpions, Vinegaroons, and Sun Spiders

Tarantula Hawks Deliver The Big Sting

Venomous Centipedes and Cyanide-Oozing Millipedes

Who’s Afraid of Tarantulas?

Rattlesnakes

Venomous Lizards

Scorpions, Vinegaroons, and Sun Spiders

Arachnophobes, this one’s for you. Scorpions, vinegaroons, and sun spiders are arachnids which means they have eight legs, simple eyes, pincers, and two main body parts: the abdomen and the cephalothorax (a fusion of head and thorax). Vinegaroons and sun spiders also have powerful jaws. You may see all three in or around your house if you live in southern Arizona.

SCORPIONS

Stripe-tailed scorpionScorpions have been around for about 400 million years. There are over 1,700 described species of which 30 species live in Arizona. The stripe-tailed scorpion is the most common in Arizona, followed by the bark scorpion, and the giant hairy scorpion. Both bark and stripe-tailed are two to three inches long. The giant hairy scorpion is up to six inches long.

Scorpions are nocturnal and diurnal. They feed upon insects, spiders, centipedes, and other scorpions. The larger scorpions go after small lizards, snakes, and rodents. In turn, they are preyed upon by owls, lizards, snakes, rodents, and bats.

Scorpion mating is a dangerous game because either one may eat the other. Mating does not involve primary copulation. Rather the male deposits a sperm packet on the ground and engages in an elaborate “dance” with the female to maneuver her over the packet. She then takes it up and may store it internally for months. She gives live birth and the newly hatched young ride on mom’s back until their first molt.

Giant Hairy ScorpionIn Arizona, only the bark scorpion has venom potentially life-threatening to humans. About 25 other species throughout the world have dangerous venom. The sting comes from the tip of the tail (the telson). The sting of a bark scorpion is about as painful as that of a bee or wasp. Symptoms of envenomation include numbness, frothing at the mouth, difficulties in breathing (including respiratory paralysis), muscle twitching, and convulsions. Deaths are rare (unless you are allergic to the venom). There is an antivenom available.

Bark ScorpionThe bark scorpion is the only one in Arizona that prefers to climb and it can cling to the underside of objects (like a piece of bark, a rock, a shoe, a piece of clothing, or a ceiling). In the house, they may get trapped in a sink or bathtub, or hide in dark areas of a closet. Outside, they may be in any loose pile of debris. The bark scorpion is the only one tolerant of others of its kind, so may live in large groups, especially in winter.

Scorpions contain a substance in their exoskeleton that makes it impermeable. It also causes scorpions to fluoresce under ultraviolet light. If you take a black light out on a summer night, you might be amazed at how many scorpions are around.

VINEGAROONS

VinegaroonVinegaroons are also known as whip scorpions. There are both tailed and tailless varieties. Although they may look formidable, they lack venom and are harmless. They do, however, have the ability to spray you, from an opening near the tail, with acetic acid (vinegar), and a solvent that attacks the exoskeleton of insects. You can handle them (see here). They are usually three to four inches long and black to dark brown.

They have four pairs of legs, but the front pair of legs are modified to act as feelers. These front legs resemble whips and are covered with many fine hairs. Vinegaroons feed mainly upon insects.

Tailless whipscorpionThese animals occur throughout southeastern Arizona and Sonora, usually at higher elevations. They may be found under rocks, tree bark, or in debris. Like scorpions, the young ride on mom’s back (see here).

 

 

 

 

SUN SPIDERS

SunspiderSun spiders are not spiders but Solpugids (or solifugae). They are also known as wind scorpions. They lack venom and are harmless. However, they have formidable jaws. They are usually one to three inches long, yellow to tan, and very hairy. They are also very fast, voracious predators. Like the vinegaroons, the front pair of legs are used as feelers.

Sun spiders prey upon insects, other arachnids, and small vertebrates, including lizards. Sun spiders are nocturnal, and good diggers. They spend most of their time underground. They are most active in Arizona during the spring and summer. I occasionally find one in my house. I generally leave them alone because they will hunt down insects, spiders, and scorpions.

Mating involves a “dance” and stroking. The male will turn the female over and deposit sperm, which the female can store for later fertilization. She will dig a burrow and deposit up to 100 eggs, but does not care for them.

Old world varieties of sun spiders, some known as camel spiders,(the subject of some wild urban legends) can get very big, about six inches long.

See also: Why do scorpions glow under UV light?