"Tarantulas" (Family Theraphosidae)
There is much diversity among species of tarantulas. Such genera as Atypus and Antrodiaetus are only a 1/2 inch or so in body length and are distributed in many scattered localities in the United States. The largest tarantulas, "mygales" or "bird spiders", are tropical and have a body length of 3-1/2 inches and a span of 9-1/2 inches with legs extended. The largest native species in the United States have a body length of about 2 inches and a leg span of about 6 inches. There is an uncertainty as to the number of native species in the United States, but the number probably is around 100. Many species are quite local or rare in distribution and the destruction of habitat may have caused the extinction of some species. However, taxonomists are still describing new species and unraveling taxonomic problems.
Most species of Tarantulas are large enough so as to be capable of biting people. However, tarantulas are usually sluggish, can be handled with ease, bite only rarely and have venom generally of little harm to most people. Within recent years, tarantulas have become acceptable pets, are sold by pet stores and championed by the American Tarantula Society and their newsletter, Tarantula Times. Such species as Mexican redlegs, Mexican blacks, Haitians and others are now widely sold, traded and kept in houses, apartments and school dormitories. Occasionally, these pets escape, sometimes creating panic among those who fear spiders. Among the native species of tarantulas, the males wander about in search of females, usually during early summer months. They sometimes stray into homes and other places where they are unwanted. In a suburb of Philadelphia, several hundred male Atypus snetsingeri were collected from a swimming pool where they were trapped in the pool's filter.
Some species of tarantulas may live for 20 years or more. Except for mate-seeking males, tarantulas are secretive with many curious habits. Trap-door spiders live in burrows in the soil and have highly camouflaged doors constructed of silk and local debrids. Atypus or purseweb spiders construct silk tubes up the base of trees or other objects.
Tarantulas are much publicized, but are rarely encountered by most people, except on the screen of movie houses and television sets. In times past when bananas were shipped as large bunches on stalks, tarantulas commonly were accidentally imported. The banana spider (not a tarantula, but a giant crab spider) was similarly found in banana bunches. Since bananas are now shipped as "hands" or small bunches, encounters with such exotics are now rare.
