Windscorpions

Carl D. Patrick
Professor and Extension Entomologist,

The Texas A&M University System

    The windscorpion appears as if it were put together from leftover parts. Even its other common names -- sunspider, sunscorpion and solifuge -- indicate some difficulty in describing the arachnid which belongs to the order Solifugae. It does not appear to be closely related to other arachnids (spiders, harvestmen, ticks, mites or whipscorpions), and bears little resemblance to other orders except for having chelicerae or jaws and four pairs of walking legs.

    The windscorpion's most striking feature is the rather enormous paired jaws which are jointed like pliers. Its body is generally hairy and often a light gray or tan color. The abdomen is bulbous and broadly joined to a huge head-like area (Fig. 1). Body size varies with age, but may approach 1 1/2 inches. Immature windscorpions and adults look almost identical and males and females cannot be told apart.

    The huge jaws in combination with the aggressive behavior frequently displayed have erroneously labeled the windscorpion as being dangerous and perhaps even poisonous. It is quite harmless to humans. There are no poison glands or fangs associated with the large jaws and no stinger at the end of the 10-segmented abdomen. The first pair of legs with their underdeveloped claws serves as tactile organs or feelers. The other three pairs of legs have well developed claws and are used for locomotion. Windscorpions also possess five pairs of racquet organs which are short, broad, T-shaped sensory structures on the hind legs.

    Prey which consists of small arthropods such as insects and spiders are captured on the run using the rather large pair of blunt leg-like structures called pedipalps located in front of the first pair of legs. The pedipalps pass the prey to the large vertically moving jaws where it is crushed to a pulp and swallowed, with any hard portion being rejected. Windscorpions are fierce predators, literally tearing their prey to bits.

    Windscorpions are most active at night, while during the day they will be found under stones, boards, logs, etc. They occasionally enter homes, but cannot survive there long. The female lays 50 to 200 "BB"-sized eggs in a burrow that she has constructed. She guards the eggs for about two weeks until they hatch and then cares for the young, even capturing prey for the whole family.

    Windscorpions make poor pets. In captivity, they stop eating and eventually die. Even experts have been unable to rear young windscorpions from eggs.

    More than 120 species of windscorpions have been described for North America. Most of the species in the United States are found in the warm, dry Southwest.

Management

    Habitat modification helps to discourage windscorpions. Around the home remove trash, logs, boards, stones, bricks and other objects under which windscorpions can develop and hide. Discourage their movement into buildings by preventing entry. Use weather stripping around doors and windows. Caulk around pipes and other cracks into the home.

    Infestations in homes probably never number more than a few individuals. Physical removal from the home or destruction by crushing will rid one of the problem in most instances. However, if rapid population reduction is necessary, insecticides may be useful. There are no household insecticides that have windscorpions listed on the label; however, products that are labeled for scorpions, spiders or centipedes will probably also kill windscorpions.

Educational programs of the Texas Agricultural Extension Service are open to all citizens without regard to race, color, sex, disability, religion, age or national origin.

Issued in furtherance of Cooperative Extension Work in Agriculture and Home Economics, Acts of Congress of May 8, 1914, as amended, and June 30, 1914, in cooperation with the United States Department of Agriculture. Zerle L. Carpenter, Director, Texas Agricultural Extension Service, The Texas A&M University System.