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Most spiders are small, inconspicuous arthropods which are harmless to humans. Their
beneficial role in keeping insect populations in check far outweighs the hazard posed by the
few spiders that occasionally bite humans. Very few of the nearly 900species of spiders in
Texas can hurt people. Only two groups--recluse spiders and widow spiders-- are
considered poisonous to humans. Tarantulas, jumping spiders, wolf spiders and some other
spiders worry people who mistakenly believe they are seriously poisonous. Although these
spiders are often large, hairy and formidable-looking, their bite is typically less harmful
than a bee sting. People who are extremely allergic to spider venom, though, react severely
to any spider bite. Many people have a phobia of spiders. However, knowing how to
distinguish harmless from dangerous spiders, how to prevent them from entering the home
and how to control those that do enter can prevent needless concern and reduce the
chances of harm to humans. Description and life cycle as their name implies, recluse spiders
are generally shy. They spin nondescript white or grayish webs, where they may hide during
the day. They are predators of insects and other arthropods, known to wander around
houses looking for prey. While walking, their body and legs together cover an area about
the size of a quarter or half-dollar, but the body itself is only 1/4 to 1/2 inch long. Their
color varies from orange-yellow to dark brown. The brown recluse’s most distinguishing
characteristics are its eye pattern and markings on the back. Recluse spiders have six eyes
arranged in three pairs in a semicircle on the forepart of the head. Uncommon in spiders,
this eye pattern helps separate recluse spiders from similar species. The eyes also form
the base of a violin-shaped marking on the back. The neck of the violin & forms a distinct,
short median groove (see Figure 1). The violin marking may be conspicuous or blend with the
background color. One other group of spiders, the spitting spiders, Scytodes, has a similar
eye arrangement. A spitting spider has long, spindly, banded legs and a spotted pattern on
its cephalothoraxes, the front body region. The cephalothorax is raised in spitting spiders
but nearly flat in recluse spiders. Slow-moving, spitting spiders are common in window sills
and considered harmless. Brown recluse spiders lay one to two egg masses per year in dark,
sheltered areas. Similar to those of many other spiders, recluse egg cases are round,
about 5/8 inch (1.6 cm) in diameter, flat on the bottom and convex on top. After 24 to 36
days, an average of 50 spider lings emerges from the egg case. Their slow development is
influenced greatly by nutrition and environmental conditions. Bite symptoms The effects of a
recluse spider bite may be immediate or delayed, depending on the amount of venom injected
and the victim sensitivity. Sometimes hardly noticed at first, the bite later causes a
stinging sensation that may include intense pain. Fever, chills, nausea, weakness,
restlessness and/or joint pain occur within 24 to 36 hours. The bite also produces a small
blister surrounded by a large congested and swollen area. The venom usually kills the
affected tissue, which gradually sloughs away and exposés underlying tissues. The edges
around the wound thicken, while the exposed center fills with dense scar tissue. Healing may
take six to eight weeks, often leaving a scar, depending on the amount of venom injected
and the reaction of the individual. Widow spiders the southern black widow, Latrodectus
mactans, and its relatives live across the entire United States. Other widow species found
in Texas are the western black widow, L. Hesperus; the northern black widow, L. various;
and probably the brown widow, L. geometricus. Their coloration varies considerably. For
proper identification, an expert may be needed to examine mature specimens. Widow spiders
are found in protected cavities outdoors. Around houses, they may live in privies, garages,
cellars, furniture, shrubbery, ventilators, rain spouts, gas and electric meters and other
undisturbed places. Widow spiders also may be seen in cotton fields and occasionally
vegetable gardens. Like most spiders, widow spiders are shy and retiring. People are bitten
occasionally when they accidentally disturb a hidden spider or its web. To avoid hidden
spiders, take care when putting on seldom-worn shoes or clothing. Description and life cycle
Widow Spiders are typically jet black, but their color can vary considerably. Males and
juveniles tend to show more color, with orange, red and white markings on the back and
sides. On the underside of their rounded abdomen are two reddish triangles that may be
united to form an hourglass shape. Some individuals have irregular or spot-like markings;
others have none at all. Adult widow spiders average 11/2 inches long and have eight eyes
in two rows, a common spider pattern. Females lay eggs in a loosely woven cup of silk. The
1/2-inch-long oval egg sacs hold from 25 to 900 or more eggs, which incubate for about 20
days, depending on temperature and time of year. Spider lings usually stay near the egg
sac for a few days after they emerge, when cannibalism is prevalent. Surviving spiderlings
disperse by They spin a single silk thread which is caught by the wind, which carries them
to a new location. When about one-third grown, they establish themselves in a protected
place and build loosely woven webs. The spiders usually remain in their rather coarse,
irregular, tangled webs for the rest of their lives. Over time they extend their webs and
capture progressively larger prey. Males eventually leave their webs to find females for
mating. Contrary to popular belief, most females do not normally eat the males after
mating. This habit, found in a few species of widow spiders from other areas, gives the
group its name. Bite symptoms if noticed at all, a widow spider bite may feel like a pin
prick. Usually the bite location is indicated by a slight local swelling and two red spots
surrounded by redness. There action is systemic and pain becomes intense in one to three
hours, continuing for up to 48 hours. Symptoms include tremors, nausea, vomiting, leg
cramps, abdominal pain, profuse perspiration, loss of muscle tone and rise in blood pressure.
The toxin can also cause breathing difficulties and sometimes unconsciousness. However, less
than 5% of people bitten by widow spiders die. Other common spiders Tarantulas in Texas
are members of the hairy mygalomorph family in the genus Aphonopelma. These large, hairy
spiders are brown to black and more than 3 inches long when full-grown. Females, larger
than males, have abdomens about the size of a quarter. Tarantulas hunt at night and spend
the day under rocks, in abandoned mouse burrows or in other sheltered areas. They may be
seen in the evening or late at night along country roads or trails. Migrating male tarantulas
can be commonly seen for a few weeks in early summer. This migration purpose is not
completely understood, but it may occur as males seek mates. Tarantulas are sometimes
kept as pets and can become quite tame. Although they can be handled, be careful,
because they can quickly become disturbed and pierce the skin with their fangs on the
chelicerae. The hair on some tarantulas may irritate the skin, so take care when handling
them. Tarantulas need a constant supply of water in a flat dish into which they can lower
their mouths. They eat live crickets, mealworms, caterpillars or other insects and can go
for several weeks without food, sometimes refusing to eat before molting. Tarantulas can
crawl up glass and escape through small openings, so they must be kept in a container with
a good lid. Jumping spiders jumping spiders, all of which are in the family Salticidae, are
among the most interesting spider groups to watch. Jumping spiders come in many sizes and
color patterns. Active hunters during the day, they have good eyesight, relying primarily on
movement to locate prey. They stalk their prey before attacking in a fast leap. Jumping
spiders put out a line of webbing when they jump and can sometimes be seen dangling from
this silken dragline after a leap that fails. Many jumping spiders are bold, stocky and often
brightly colored. They often have conspicuous bands of black and white on their bodies or
legs. Others have velvety red abdomens and some even have metallic colors on the
chelicerae. Jumping spiders have eight eyes, with one large pair in the front. Like most
spiders, jumping spiders are not considered hazardous to humans and are unlikely to bite
unless cornered or handled. The bold jumper, Phidippus audax, is one of the most common
and conspicuous of the jumping spiders. It is black with a distinct irregular orange to white
spot on the back of the abdomen. It can be found in gardens and around homes. Wolf
spiders Wolf spiders hunt at night. Usually brown and black, they may have longitudinal
stripes. Wolf spiders are large and often seen under lights. They can be seen at night
when their eyes reflect light from a flashlight, headlamp or car headlight. Members of the
genera Rabidosa and Hogna are some of the most conspicuous wolf spiders. They form
webbing only to provide daytime shelter, not to capture prey. Many wolf spider females
carry their egg masses below their abdomens until after the eggs hatch. Young spiderlings
cling to the mother abdomen for a short time after hatching. Wolf spiders frequently enter
homes and backyards but pose no danger to people.
beneficial role in keeping insect populations in check far outweighs the hazard posed by the
few spiders that occasionally bite humans. Very few of the nearly 900species of spiders in
Texas can hurt people. Only two groups--recluse spiders and widow spiders-- are
considered poisonous to humans. Tarantulas, jumping spiders, wolf spiders and some other
spiders worry people who mistakenly believe they are seriously poisonous. Although these
spiders are often large, hairy and formidable-looking, their bite is typically less harmful
than a bee sting. People who are extremely allergic to spider venom, though, react severely
to any spider bite. Many people have a phobia of spiders. However, knowing how to
distinguish harmless from dangerous spiders, how to prevent them from entering the home
and how to control those that do enter can prevent needless concern and reduce the
chances of harm to humans. Description and life cycle as their name implies, recluse spiders
are generally shy. They spin nondescript white or grayish webs, where they may hide during
the day. They are predators of insects and other arthropods, known to wander around
houses looking for prey. While walking, their body and legs together cover an area about
the size of a quarter or half-dollar, but the body itself is only 1/4 to 1/2 inch long. Their
color varies from orange-yellow to dark brown. The brown recluse’s most distinguishing
characteristics are its eye pattern and markings on the back. Recluse spiders have six eyes
arranged in three pairs in a semicircle on the forepart of the head. Uncommon in spiders,
this eye pattern helps separate recluse spiders from similar species. The eyes also form
the base of a violin-shaped marking on the back. The neck of the violin & forms a distinct,
short median groove (see Figure 1). The violin marking may be conspicuous or blend with the
background color. One other group of spiders, the spitting spiders, Scytodes, has a similar
eye arrangement. A spitting spider has long, spindly, banded legs and a spotted pattern on
its cephalothoraxes, the front body region. The cephalothorax is raised in spitting spiders
but nearly flat in recluse spiders. Slow-moving, spitting spiders are common in window sills
and considered harmless. Brown recluse spiders lay one to two egg masses per year in dark,
sheltered areas. Similar to those of many other spiders, recluse egg cases are round,
about 5/8 inch (1.6 cm) in diameter, flat on the bottom and convex on top. After 24 to 36
days, an average of 50 spider lings emerges from the egg case. Their slow development is
influenced greatly by nutrition and environmental conditions. Bite symptoms The effects of a
recluse spider bite may be immediate or delayed, depending on the amount of venom injected
and the victim sensitivity. Sometimes hardly noticed at first, the bite later causes a
stinging sensation that may include intense pain. Fever, chills, nausea, weakness,
restlessness and/or joint pain occur within 24 to 36 hours. The bite also produces a small
blister surrounded by a large congested and swollen area. The venom usually kills the
affected tissue, which gradually sloughs away and exposés underlying tissues. The edges
around the wound thicken, while the exposed center fills with dense scar tissue. Healing may
take six to eight weeks, often leaving a scar, depending on the amount of venom injected
and the reaction of the individual. Widow spiders the southern black widow, Latrodectus
mactans, and its relatives live across the entire United States. Other widow species found
in Texas are the western black widow, L. Hesperus; the northern black widow, L. various;
and probably the brown widow, L. geometricus. Their coloration varies considerably. For
proper identification, an expert may be needed to examine mature specimens. Widow spiders
are found in protected cavities outdoors. Around houses, they may live in privies, garages,
cellars, furniture, shrubbery, ventilators, rain spouts, gas and electric meters and other
undisturbed places. Widow spiders also may be seen in cotton fields and occasionally
vegetable gardens. Like most spiders, widow spiders are shy and retiring. People are bitten
occasionally when they accidentally disturb a hidden spider or its web. To avoid hidden
spiders, take care when putting on seldom-worn shoes or clothing. Description and life cycle
Widow Spiders are typically jet black, but their color can vary considerably. Males and
juveniles tend to show more color, with orange, red and white markings on the back and
sides. On the underside of their rounded abdomen are two reddish triangles that may be
united to form an hourglass shape. Some individuals have irregular or spot-like markings;
others have none at all. Adult widow spiders average 11/2 inches long and have eight eyes
in two rows, a common spider pattern. Females lay eggs in a loosely woven cup of silk. The
1/2-inch-long oval egg sacs hold from 25 to 900 or more eggs, which incubate for about 20
days, depending on temperature and time of year. Spider lings usually stay near the egg
sac for a few days after they emerge, when cannibalism is prevalent. Surviving spiderlings
disperse by They spin a single silk thread which is caught by the wind, which carries them
to a new location. When about one-third grown, they establish themselves in a protected
place and build loosely woven webs. The spiders usually remain in their rather coarse,
irregular, tangled webs for the rest of their lives. Over time they extend their webs and
capture progressively larger prey. Males eventually leave their webs to find females for
mating. Contrary to popular belief, most females do not normally eat the males after
mating. This habit, found in a few species of widow spiders from other areas, gives the
group its name. Bite symptoms if noticed at all, a widow spider bite may feel like a pin
prick. Usually the bite location is indicated by a slight local swelling and two red spots
surrounded by redness. There action is systemic and pain becomes intense in one to three
hours, continuing for up to 48 hours. Symptoms include tremors, nausea, vomiting, leg
cramps, abdominal pain, profuse perspiration, loss of muscle tone and rise in blood pressure.
The toxin can also cause breathing difficulties and sometimes unconsciousness. However, less
than 5% of people bitten by widow spiders die. Other common spiders Tarantulas in Texas
are members of the hairy mygalomorph family in the genus Aphonopelma. These large, hairy
spiders are brown to black and more than 3 inches long when full-grown. Females, larger
than males, have abdomens about the size of a quarter. Tarantulas hunt at night and spend
the day under rocks, in abandoned mouse burrows or in other sheltered areas. They may be
seen in the evening or late at night along country roads or trails. Migrating male tarantulas
can be commonly seen for a few weeks in early summer. This migration purpose is not
completely understood, but it may occur as males seek mates. Tarantulas are sometimes
kept as pets and can become quite tame. Although they can be handled, be careful,
because they can quickly become disturbed and pierce the skin with their fangs on the
chelicerae. The hair on some tarantulas may irritate the skin, so take care when handling
them. Tarantulas need a constant supply of water in a flat dish into which they can lower
their mouths. They eat live crickets, mealworms, caterpillars or other insects and can go
for several weeks without food, sometimes refusing to eat before molting. Tarantulas can
crawl up glass and escape through small openings, so they must be kept in a container with
a good lid. Jumping spiders jumping spiders, all of which are in the family Salticidae, are
among the most interesting spider groups to watch. Jumping spiders come in many sizes and
color patterns. Active hunters during the day, they have good eyesight, relying primarily on
movement to locate prey. They stalk their prey before attacking in a fast leap. Jumping
spiders put out a line of webbing when they jump and can sometimes be seen dangling from
this silken dragline after a leap that fails. Many jumping spiders are bold, stocky and often
brightly colored. They often have conspicuous bands of black and white on their bodies or
legs. Others have velvety red abdomens and some even have metallic colors on the
chelicerae. Jumping spiders have eight eyes, with one large pair in the front. Like most
spiders, jumping spiders are not considered hazardous to humans and are unlikely to bite
unless cornered or handled. The bold jumper, Phidippus audax, is one of the most common
and conspicuous of the jumping spiders. It is black with a distinct irregular orange to white
spot on the back of the abdomen. It can be found in gardens and around homes. Wolf
spiders Wolf spiders hunt at night. Usually brown and black, they may have longitudinal
stripes. Wolf spiders are large and often seen under lights. They can be seen at night
when their eyes reflect light from a flashlight, headlamp or car headlight. Members of the
genera Rabidosa and Hogna are some of the most conspicuous wolf spiders. They form
webbing only to provide daytime shelter, not to capture prey. Many wolf spider females
carry their egg masses below their abdomens until after the eggs hatch. Young spiderlings
cling to the mother abdomen for a short time after hatching. Wolf spiders frequently enter
homes and backyards but pose no danger to people.
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