F-532018 
Figure 9.—Centruroides vittatus, the striped scorpion. 
Pseudoscorpions may be found in a wide variety of places—in soil cover, under 
bark, under the wings of beetles, on the bodies of birds and in their nests, in 
buildings, in chicken houses, and in beehives. Their food consists of mites, ants, 
and various other insects. One species, Chelifer cancroides (L.), is frequently found 
in association with humans. Adults are about 2.5 to 3 mm long (582). 
Order Opiliones—Daddylonglegs 
Daddylonglegs are somewhat similar in appearance to spiders but differ in having 
small, compact, nearly globular bodies and extremely long legs. They also are 
rather slow in movement, usually appearing to totter about, and they occur com- 
monly in most parts of the United States. Their food consists chiefly of plant juices 
or dead insects. Some apparently feed on living insects. When crushed, their bodies 
give off a disagreeable odor. None is harmful to humans. 
Order Araneae—Spiders 
Spiders are found almost everywhere, both indoors and outdoors, and are so 
familiar as to need no description (229). Objects of fear and revulsion to many 
people, their presence in large numbers in and around places of habitation, or other 
areas frequented by people, is often considered intolerable. Fortunately, the major- 
ity of species pose no hazard to humans, even though all have venom glands. 
Actually, they generally are more beneficial than harmful since their food consists 
mainly of insects and other small organisms. A few species, however, are poisonous 
to humans and should be avoided (35). 
The black widow spider, Latrodectus mactans (F.), is probably the most 
poisonous spider in the United States. The effect of its bite is described as being 
extremely painful throughout all the muscles of the body, and it occasionally results 
in death. The black widow occurs from southern Canada southward through the 
United States, Mexico, Central America, and deep into South America. In the 
Eastern States it is most common in the South, but also occurs as far north as 
Maine. 
Black widows are usually found in such places as garages, sheds, outdoor toilets, 
under rocks and old boards, and in hollow logs or animal burrows. The female is 
shining jet black and bears an hourglasslike red mark on the underside of the 
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