Spiders
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 900 species 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. 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.
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 900 species 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. 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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Contact Crown Pest Control
CROWN Pest Control
7408 Tunbridge Drive
N. Richland Hills, TX 76180-4535
PHONE: 817-485-8774
FAX: 817-428-3729
EMAIL: info@crownpestcontrol.com
MEMBER: Greater Tarrant County Pest
Control Assoc., Texas Pest Control Assoc.,
National Pest Management Assoc.
Licensed and Regulated by the Texas
Structural Pest Control Board, P.O.Box 1927,
Austin, TX 78767-1927. Telephone number
(512) 305-8250.
CROWN Pest Control
7408 Tunbridge Drive
N. Richland Hills, TX 76180-4535
PHONE: 817-485-8774
FAX: 817-428-3729
EMAIL: info@crownpestcontrol.com
MEMBER: Greater Tarrant County Pest
Control Assoc., Texas Pest Control Assoc.,
National Pest Management Assoc.
Licensed and Regulated by the Texas
Structural Pest Control Board, P.O.Box 1927,
Austin, TX 78767-1927. Telephone number
(512) 305-8250.
817-485-8774