Forest Preserve District of Cook County, Illinois
Nature Bulletins
Newton Home Page

Introduction and Instructions

Search Engine

Table of Contents

Copyright

Disclaimer

Scorpions
Nature Bulletin No. 652-A   October 22, 1977
Forest Preserve District of Cook County
George W. Dunne, President
Roland F. Eisenbeis, Supt. of Conservation

SCORPIONS
Scorpions have been feared since ancient times. Some kinds, especially in the tropics, are dangerously poisonous and their stings are frequently fatal, but there seems to be something menacing and evil about even those that are comparatively harmless.

A scorpion is an arachnid, eight-legged and related to the spiders, but it looks more like a crayfish with a skinny tail. It has a pair of appendages extending from each side of the mouth and ending in powerful pincers. Those are called pedipalpi because on spiders and other arachnids they resemble legs, but on scorpions they resemble the claws of a crayfish. The last five segments of the abdomen are slender and form a conspicuously jointed "tail. " At the end of it is a curved, pointed stinger with an enlarged base containing a pair of poison glands. When attacking, a scorpion arches its tail over the back and plunges it forward to sting.

Scorpions lead lonesome lives. They avoid each other or fight until one is killed -- then eaten. The males, more slender and with longer tails, are often killed and devoured by the females after mating. The fertilized eggs develop inside the mother and the young are born alive. Then they climb upon her back and, with only her pedipalpi, legs and tail visible, she carries them around but does not feed them. They exist upon egg yolk in their mid-gut. They molt their shells as they grow and soon after the first molt, resembling an adult but many times smaller, they drop off and each little cannibal goes his or her own way.

A scorpion has a central pair of eyes and, depending upon the species, from three to five pairs of smaller lateral eyes. In front of the mouth there is a second pair of appendages, much shorter than the pedipalpi, equipped with small but powerful pincers for mashing and shredding food. The first pair of legs have glands secreting digestive enzymes.

Scorpions prey chiefly upon insects but spiders, millipedes and centipedes are also eaten. When a scorpion is hungry it seizes an insect with the pincers of the pedipalpi, paralyzes it with the stinger, mashes it with the shorter appendages, injects enzymes into it and, when all of the insect's tissues have become fluid, sucks it dry. Nothing but the empty chitinous shell remains. However, scorpions can live more than a year without eating.

There are at least 300 species of scorpions, most of them in tropical or desert regions, and they vary in length from one-half inch to more than seven inches. Some are reddish, some yellow, and some green. There are scorpions in Europe and 30 species are known to occur in the United States southwest of a line drawn from North Dakota to the Carolinas. Apparently they do not occur in Illinois..

There are at least two types of scorpion poison. One is comparatively harmless to man. It causes sudden sharp pain, followed by numbness and local swelling, but after an hour or two the effects are usually gone unless the victim is a child or unusually allergic to such venom. The other type is neuro-toxic and similar to the venom of the coral snake and the cobras. The symptoms resemble poisoning with strychnine and frequently death results. Many fatalities from scorpion stings occur in parts of Mexico.

Scorpions, active at night, hide in daytime under stones, logs and rubbish; in crevices of rocks; in barns, sheds and old buildings; and are apt to crawl into houses, tents, and even beds. In scorpion country we empty shoes and shake our clothes before putting them on. "Scorpio" is a sneak.

Up-date January 2001- one species of scorpion is native to Southern Illinois.



To return to the Nature Bulletins Click Here!
Hosted by NEWTON

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs

NEWTON AND ASK A SCIENTIST
Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Sponsered by Argonne National Labs