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