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INTRODUCTION
The common name was applied by Europeans to the large, hairy spiders of the
southwest and western United States probably because of the resemblance to a large
European wolf spider that took its name from the city of Taranto in Italy. Myth was that
people who thought they were bitten had a huge desire for dancing with the frenzied dance
being referred to as 'larantism", and the legend grew; the bite of that spider is no
more dangerous than that of other wolf spiders. Although some people become alarmed when
tarantulas are found indoors, they are primarily a nuisance pest; bites by United States
species are no more harmful than a bee sting but they may shed hairs which cause itching.
There are about 30 species found in the United States with most occurring in the south
central states but more commonly in the southwestern states.
RECOGNITION
Adult female body length 1 3/4-2 7/8" (43-70 mm) and a leg span of up to
5" (130 mm), male body length about 1 9/16-2 9/16" (40-65 mm); robust and very
hairy. Color usually dark brown to blackish, sometimes tan to yellowishlreddish brown
and/or with reddish golden hairs etc.; one species with dark spot on light-colored
abdomen. Chelicerae (jaws) move vertically (vs jaws of all true spiders move horizontally)
up and down so fangs move in plane almost parallel to median plane of body (=paraxial),
front of body must be raised to plunge fangs downward; fang with distinct furrow/groove.
Abdomen with 2 pairs of slit openin_qs to booklun_qs Oust to rear of 4th pair of legs) and
anal tubercle immediately behind (above) 4 spinnerets. Tarsi each with 2 claws and claw
tuft (bunch of hairs at tarsal tip).
SIMIILAR GROUPS
Purseweb spiders (Atypidae), foldingdoor trapdoor
spiders (Antrodiaetidae) and sheetweb weaving atypical tarantulas (Mecicobothriidae) have
abdomen usually with 1-3 scierotized tergites (hard dorsal plates), cheliceral fang furrow
indistinct, and anal tubercle separated from spinnerets by considerable distance.
Trapdoor spiders (Ctenizidas) and sheetweb/funnelweb building tarantulas (Dipluridae)
have tarsi with 2 large lateral and a small median claw, without claw tufts (pad of
hairs).
Wolf spiders (Lycosidae) with chelicerae diaxial (fangs move in transverse plane towards
each other), and usually with only 1 pair of booklung slits just behind 4th pair of legs.
REPRESENTATIVE SPECIES
- Aphonopelma chalcodes Chamberlain. Adult female body length about 2 7/8" (70 mm)
and leg span of about 5" (130 mm), male body length about 2 9/16" (65 mm); color
dirty yellowish brown with abdomen, leg coxa-trochanter-femur, and lst segment of
pedipalps dark brown; found in Arizona.
- Aphonopelma euvenum (Chamberlain). Adult female body length about 1 11/16" (43 mm),
male body length about 1 9/16" (40 mm); color blackish to dark brown; found in
California.
- Dugesiella hentzi (Girard). Adult female body length 1 3/4-2 1/4" (44-58 mm), male
body length 1 1/4-2 1/16" (32-52 mm); cephalothorax and legs dark brown with reddish
golden hairs on carapace (cephalothorax dorsum), abdomen brownish black; found in southern
Missouri and Kansas south through Oklahoma, Arkansas, and Louisiana.
BIOLOGY
Mating occurs in the autumn, and the female produces an egg sac the following
summer (July). The egg sacs average 800-850 eggs each, and are up to 2-3" (50-75 mm)
in diameter. After their first molt, young tarantulas venture out on their own. They molt
about once each year and become adults in 5-7 years (some require 10-12 years). Adult
males die about 6 months after reaching maturity. Adult females are very long-lived, often
living in excess of 20 years (?35 years). Adult females continue to mate once each year
and produce an egg sac the following spring. They also continue to moli once each year
during which any damaged palps and/or legs are replaced.
Tarantulas are not seriously poisonous to humans. Their bites usually result in
pinpricks with mild pain, but can be very painful because of the large cheleceras (fangs).
However, the pain usually subsides in 30-60 minutes. Sensitive individuals may have more
serious reactions, but serious injury or death is not likely to occur. Tarantulas are not
aggressive and must usually be provoked to bite.
A physical encounter, such as handling a tarantula, may result in an itch. When
disturbed, many tarantulas have the habit of rubbing off some of the hairs on the rear oi
their abdomen with the hind legs; this can result in a bald spot. These hairs are kinked
and barbed such that they will cause irritation when they contact human skin. The allergic
response to these hairs is likely to cause great discomfort.
HABITS
Tarantulas are nocturnal and spend most days secluded in their burrows ol
retreats. These are located in natural cavities in the ground, in old rodent burrows,
undei stones or debris on the ground, in cracks of trees, etc. They line the upper portion
of their burrow with silk.
They usually hunt in the general area surrounding their burrow. Often, they may wail
inside their burrow until a prey insect or spider gets close enough for capture. A numbei
of tarantulas often occupy the same general area such as a hillside or pasture.
Females usually do not leave the vicinity of their burrows. However, males wander foi
considerable distances during the late summer and autumn (July to November) matin@ season
in search of a mate. Sometimes males can be seen by the dozens wanderinc across roads and
backyards.
As long as they have water, tarantulas can live for up to 2
years without eating. Foi pet tarantulas, crickets from the local pet store, bait shop, or
yard are a good food.
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