The
four species of widow spiders are very similar in body shape. All are
about 1/2" long with legs extended. Their life cycle is also similar.
The female lays about 250 eggs in a pear-shaped egg sac that is about
1/2" to 5/8" in diameter. The eggs hatch in about 20 days. As the young
spiders mature, they construct a loosely woven web and capture
progressively larger prey. In Florida, all the widows except the
northern black widow breed year-round. Anyone bitten by a spider should
preserve it in rubbing alcohol for positive identification. Most spider
bites are not considered dangerous, but if you suspect one of the widow
or brown recluse spiders, get medical
attention immediately.
Brown
Widow Spiders- The brown widow is established pretty much
throughout the Florida peninsula. It is found most often south of
Daytona Beach along the coast. The brown widow builds its web in
secluded, protected sites around our homes, often very near our
presence. It has a fondness for buildings but will construct its web in
all kinds of man-made structures, and even vegetation. Some typical
sites include inside old tires, empty containers such as buckets and
nursery pots, mail boxes, entry way corners, under eaves, stacked
equipment, cluttered storage closets and garages, behind hurricane
shutters, recessed hand grips of plastic garbage cans, underneath
outside chairs, and in branches of shrubs.
Because
brown widow spiders vary from light tan to dark brown or almost black,
with variable markings of black, white, yellow, orange, or brown on the
back of their abdomens, brown widows are not as easy to recognize. The
underside of the abdomen, if you can see it, contains the characteristic
hourglass marking. Unlike the black widow, the hourglass is orange to
yellow orange in color. The brown widow is also slightly smaller than
the black widow. The egg sac looks like an old naval mine or a sandspur
seed.
Brown
widow spiders are extremely timid; the only bites reported have resulted
from a spider being accidentally trapped against the victim's body.
Brown widow spider bites are however becoming more common. The venom of
the brown widow may be twice as potent as the black widow, experts
believe, but the brown widow is less inclined to inject larger amounts
of venom. Brown widow bite symptoms can include pain, rigidity in the
muscles of the abdomen and legs, swelling, nausea, vomiting and in
severe cases a sharp rise in blood pressure. Generally, the symptoms of
the brown widow tend to stay localized to the bite site, whereas the
black widow's symptoms are more widespread.
Black
Widows - The southern black widow is the most widespread widow
spider in Florida. It is glossy black and has a complete hourglass
marking on the underside of the abdomen. The black widow spider's body
is about 1/4-1/2 inch long and 3/4 to 1 and ½ inches wide when legs are
spread out. The northern black widow has the same general appearance,
but has two red triangles resembling an hourglass and a row of red spots
on top of the abdomen. The northern species is found west of
Tallahassee, primarily in forests, with its webs three to 20 feet above
the ground. The southern black widow is usually found outdoors in
protected places, such as under rocks and boards, and in and around old
buildings.
The black widow spider’s venom is a potent neurotoxin and is considered
the most venomous spider in North America. However, the female injects
such a small dose of venom that it rarely causes death. They are timid
and solitary, and often bite only when disturbed. All encounters with
humans can be attributed to the female. The bite of the black widow and
other widow spiders usually feels like a pin prick. The initial pain
disappears rapidly, leaving local swelling and two tiny red marks.
Muscular cramps in the shoulder, thigh and back usually begin within 15
minutes to three hours. In severe cases, pain spreads to the abdomen,
the blood pressure rises, and there is nausea, sweating and difficulty
in breathing. Death may result, depending on the victim's physical
condition, age and location of bite. Death seldom occurs if a physician
is consulted and treatment is prompt.
Red
Widow Spiders- The red widow has a black abdomen with a single
flattened red triangle on the underside. On the back are rows of red
spots, each of which are surrounded by a yellow circle. The head region
and legs are red-orange in color. The red widow spider's web begins as a
typical tangle web in the interior of a small palm or palmetto, but then
continues as a sheet of silk onto one of the lateral open leaves. Red
widow spiders are endemic to Florida. It occurs in sandpine scrub from
Marion County to Martin County. Because of both its rarity and its
beautiful coloring, the red widow spider is a collector's item for
people who collect spider specimens. Little is known of the bite of the
red widow, but its venom is probably quite toxic to mammals.
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