StoryImage( ‘/Images/Story//Auto-img-117269556131203.jpg’, ‘Photo by Dr. Robert A. Hedeen’, ‘The sting of this common scorpion in the southern and southwestern U.S. is painful but not usually dangerous.‘);
We who live in northern Illinois are fortunate in that we do not have to watch out for scorpions and the painful sting they can administer. They are mainly creatures of the south and southwest, and those who have lived or visited in that region for any length of time know they are to be avoided at all times.
Scorpions are members of the class Arachnida (spiders, ticks, mites) of the great group of jointed-legged invertebrate animals known as the Arthropoda. They are flattened animals that somewhat resemble crabs and are only a few inches in length. They are easily recognized by their five-segmented tail, which is not a tail at all but an extension of the abdomen, and a pair of the mouth parts that are greatly extended and bear strong pincher-like structures at the end. The business end of the scorpion is located in the last segment of the tail-like abdomen and consists of a large, curved spine-like stinger that is connected to two venom glands.
When the scorpion stings, either in defense or the acquisition of prey (or seemingly just for the heck of it), the victim is grasped in the pinchers, and the stinger swings forward to penetrate the unfortunates body. These arachnids feed on insects, spiders, millipedes and even small mammals. They are nocturnal in nature, doing most of their hunting at night, and are inactive during the day when they seek shelter under rocks, tree bark, privies, wood piles, and inside ones house if entrance can be gained.
Campers in the south always make it a practice to shake out their boots and bed rolls each morning, as these are favorite places for a scorpion to seek shelter. The female scorpion is somewhat unique in that she is ovoviviparus and gives birth to living young. Her eggs are hatched within the body, and the young are born in an advanced state of development. They cling to their mothers upper surface for a considerable time until their bodies harden, and they are able to fend for themselves.
There are about 650 known species of scorpions worldwide, with about 40 in the United Sates. The most common one in the U.S. is the yellowish, striped scorpion, Centrtruroides vitattus. Its sting is quite painful for a short period of time but is not considered to be dangerous unless one happens to be particularly allergic to the venom. The application of an ice cube to the sting site will help alleviate the pain. I have been stung by this scorpion several times and can attest to sharp, burning pain that resulted. Some other animals are affected acutely by the sting.
Some years ago, my colleague Major (Dr.) Hugh L. Keegan and I, at the Armys Medical Field Service School, conducted an investigation of the relative potency of various venomous animals. We found that the venom of C. vitattus was five times more lethal to white rats that of the black widow spider.
The sting of a few scorpions south of the border may prove to be fatal to humans. A few of these scorpions may be occasionally found in southern Arizona or New Mexico. The most infamous of these is a relative of the notorius Durango scorpion, and an antivenin is available in those areas and is the recommended treatment. This beast is quite common in the state of Durango in Mexico, and its sting is frequently fatal to children, especially those younger than 7. Over the years, a few deaths have been recorded from scorpion sting in the U.S.
A professor of mine once told the story of a battle he arranged between a scorpion and a praying mantis. He placed the two combatants in a glass terrarium and observed the action. As the two circled about one another, the scorpion made numerous attempts to sting the mantid, but the insect would always dodge the lethal thrust of the stinger. After a time, the mantid saw its chance and deftly snapped off the scorpions stinger. Thusly disarmed, the mantid made short work of devouring the defenseless scorpion.
If you have occasion to travel to the south or southwest and are an outdoors person, you should always be aware that a scorpion may choose you as its next victim.
Dr. Robert Hedeen is a former resident of Marylands eastern shore and resided in the Chicago area from 1960 to 1971. He is a retired professor emeritus of biological sciences in the University of Maryland system. He has published more than 30 scientific papers, has written numerous magazine articles, and is the author of two books on the natural history of the Chesapeake Bay.
From the Feb. 28-March 6, 2007, issue