Spiders

Florida Spiders
Spiders belong to the class Arachnid, which contains organisms with four pairs of legs, no antennae, and two body regions.

Crab spiders Crab spiders are so named because they hold their legs to the side in a crab-like fashion. These spiders do not spin webs, but wait in ambush on flowers and foliage for their insect prey. Crab spiders are extremely well camouflaged, blending in perfectly with the flowers among which they live.

Jumping spiders The jumping spiders belong to the family Salticidae and are sometimes called salticids. All species are small, usually less than 15mm long. They are easily identified by their eye arrangement, which is in three rows. Jumping spiders do not construct webs, but actively hunt prey during the day, pouncing on their luckless victims. Many are brightly colored, sometimes with iridescent mouthparts.

Wolf spiders They are very common and usually found on the ground, here they are well camouflaged. The Carolina wolf spider is the largest in the U.S. with a size of 25 to 35mm. These spiders do not spin webs, but some dig burrows or hide under debris.

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Golden silk spider The golden silk spider is found throughout Florida. The female is distinctively colored and among the largest orb-weaving spiders in the country. The female varies from 25 to 40mm long and has conspicuous hair tufts on her long legs. Males are small, approximately 4 to 6mm in length, dark brown in color, and often found in the webs of females. These spiders feed primarily on flying insects which they catch in webs that may be greater than a meter in diameter. They are most commonly found in areas with trees.

Spiny orb-weaver The spiny orb-weaver spider is one of the most colorful and easily recognized spiders in Florida. The dorsum of the abdomen is usually white with black spots and large red spines on the margin. Females range from 5 to 10mm long and 10 to 14mm wide. The webs typically contain tufts of silk, which may prevent birds from flying into them.

Black and yellow argiope spider The argiope spiders are a large and distinctive group. Their large, conspicuous webs can often be seen along the edge of woodlands. The black and yellow argiope can reach a length of 25mm. Its characteristic silver carapace and yellow and black markings make it easy to identify. Argiope spiders tend to hang head down in the middle of a medium-sized web that has thickened, zigzag bands of silk in the center.

Green lynx spider This spider is commonly encountered on shrubs, weeds, and foliage. The female ranges from 12 to 20mm in length, while the male seldom gets beyond 12mm. The body is a vivid, almost transparent green, with red spots and some white markings. The legs are long, slender and covered at intervals with long, black spines. These spiders have good eyesight and hunt and stalk their prey during the daytime. They spin no webs, but sometimes anchor themselves with silk.

Long-jawed orb-weavers These spiders have the characteristic behavior of clinging to a support with their short third pair of legs while holding their remaining and much longer legs in an extended manner both in front of and behind the body. They spin small webs that are 8 to 12" in diameter. They are often found in association with foliage bordering water.

Venomous Spiders in Florida

Five species of venomous spiders occur in Florida:
The Southern black widow, Northern black widow, red widow, brown widow and brown recluse.

The four species of widow spiders are very similar in body shape. All are about 1 1/2" long with legs extended. Their life cycle is also similar. The female lays approximately 250 eggs in an egg sac which is pear shaped and about ½ to 5/8" in diameter. The eggs hatch in approximately 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.

If bitten by a spider, preserve it in rubbing alcohol for positive identification. Most spider bites are not considered dangerous, but if one of the widow or brown recluse spiders are suspected, get medical attention immediately.

Southern black widow This 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 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 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, 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 This species has a reddish-orange head, thorax and legs with a black abdomen. The top of the abdomen usually has a row of red spots with yellow borders. This spider lacks a complete hourglass on the underside of the abdomen and instead usually has one or two small red marks. The red widow constructs its web in palmettos and has been found primarily in sandpine scrub habitats in central and southeast Florida.

Brown widow This spider varies in color from light gray to light brown to black. The abdomen has variable markings of black, white, red and yellow. The underside of the abdomen has an orange or yellow hourglass. It is found most often south of Daytona Beach along the coast. It usually makes its web on buildings in well lighted areas.

Brown recluse This is not an established species in Florida. It is recognized by the distinctive dark violin-shaped mark located on the head and thorax. The brown recluse is a medium-sized spider about ¼ to1/2 in length. It is light tan to deep reddish brown. It is usually found in sheds, garages or areas of homes that are undisturbed and contain a supply of insects to serve as food. Favorite hiding places seem to be in arms and legs of garments left hanging for some time or beds that have been unoccupied for long periods of time. Persons bitten by this spider usually do not feel pain for two to three hours. A blister arises at the site of the bite followed by inflammation. Eventually the tissue is killed, leaving a sunken sore. Healing may take as long as six to eight weeks.

Household Spiders
There are about 1000 species of spiders in the United States. They live everywhere, including homes and buildings. Some species are able to bite humans and inject a venom into the skin.
The brown recluse and the widow spiders are considered venomous spiders.

BIOLOGY AND DESCRIPTION
All spiders have 8 legs and 2 body regions. They are predators, feeding primarily on insects and other arthropods.
When feeding, spiders inject a digestive fluid into their prey, then suck up the digested food. They can survive for long periods of time without feeding. Some spiders have been kept alive for over 2 years without feeding.

Because spiders feed entirely on living insects or other animals, they may actively search for their prey, hide and wait for them to pass, or build webs to trap flying insects.
Most web-spinning spiders build and abandon several webs per year. The webs are produced by glands on the spider's abdomen. The silk is a liquid which hardens when exposed to the air.
Silk is used to construct webs, safety lines, egg sacs and as parachutes for long distance travel. Spiders reproduce by laying eggs in a silken egg sac. The egg sac is either carried around by the female or hidden in the web.
Egg sacs of large spiders may contain several hundred eggs. The eggs hatch in about 2-3 weeks after they are deposited. Most young spiders mature to adults in about one year.
Male and female spiders live separately and only come together to mate.
Males are usually smaller and color-marked differently than females. Almost all spiders found in Florida are harmless to humans and most species do not attempt to bite unless they are provoked. Spiders usually remain hidden and do not seek out humans to bite. Most spiders cannot penetrate the skin of a human with their fangs.

Almost all spiders possess venom, but only a few are considered dangerous to humans.

Spiders are of interest since some invade homes, others are considered poisonous, and some larger species are raised as pets.

HOUSE SPIDERS
Several species of spiders enter houses and become a nuisance. Many people simply dislike spiders and cannot tolerate their presence. When numerous, spiders are annoying because they construct webs. Abandoned webs collect dust, resulting in cobwebs.
Newly hatched spiders are tiny and easily enter homes through screens or around loose fitting doors and windows. Careful screening will keep larger spiders out of homes.

If the insects they eat are not plentiful, spiders are less likely to infest a home. Chemical control of spiders is difficult outdoors because web-spinning spiders do not tend to contact treated surfaces.
NOTE:
Our Technicians ALWAYS sweep away webs and spider debris, prior to using any chemical treatment!

Inside the house, space sprays containing pyrethrums or parathyroid are effective in killing spiders. Space sprays have little residual activity and should be applied when spiders are noticed. When spraying enclosed areas, care should be taken so spiders agitated by the spray do not drop onto the person doing the spraying.

Dust formulations can be used in crawl spaces, attics and utility areas to provide long-term protection. Insecticide dusts tend to cling to the spider webs for long periods of time. When spiders chew their webs to recycle the silk they consume the toxicant and die.