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- Wolf spider (family Lycosidae).
The black widow is responsible for more than 2, visits to poison control centers every year in the U. The most common member of Latrodectus in North America, it makes its home in a variety of settings, such as woodpiles, burrows, or among plants that serve as supports for its web. The female is shiny black and usually has a reddish to yellow hourglass design on the underside of the spherical abdomen. Sometimes two small triangles, instead of a complete hourglass, are present.
The body is about 2. In addition to the hourglass design, the male often has pairs of red and white stripes on the sides of the abdomen. Its bite, which may feel like a pinprick on the skin, often produces severe muscle pain and cramping, nausea, and mild paralysis of the diaphragm, which makes breathing difficult. Most victims recover without serious complications. Although the bite is thought to be fatal to very small children and the elderly, no deaths have been attributed to bites by widow spiders in the United States. The brown widow is thought to have evolved in Africa, but the first specimen described came from South America.
It is classified as an invasive species elsewhere around the world. Brown widow populations have appeared in southern California, the Caribbean, the U. The species makes its home in buildings, inside old tires, and under automobiles, as well as among shrubs and other vegetation. The spider has a brownish appearance that ranges from tan to almost black. The abdomens of some specimens have ornate dark-brown, black, white, yellow, or orange markings. Unlike other members of the genus, the hourglass marking on the underside of the brown widow is orange. Brown widow venom is considered to be twice as powerful as that of the black widow; however, the species is not aggressive and only injects a tiny amount of venom when it bites.
Still, brown widow bites were associated with the deaths of two people in Madagascar in the early s. These victims they were in poor health and they were not treated with antivenin. The third widow spider on this list is the red widow, or red-legged widow. Many red widows have a red mark on the underside of the abdomen, which may be either hourglass-shaped, triangle-shaped, or indistinct. The top of the abdomen is spotted red or orange, with each spot surrounded by a yellow or white outline.
The legspan of an adult female is 1. Currently, red widow spiders inhabit palmetto-dominated scrublands in central and southern Florida; however, some experts believe that this range may be expanding. The spider feeds on insects, and it is not considered to be aggressive toward people. The bite of the red widow is similar to that of the black widow, and identical symptoms pain, cramping, nausea, etc.
Likewise, death from a red widow bite is rare, since the spider injects such a small amount of venom. Very young children, the elderly, and people with health problems are most vulnerable to red widow spider bites. The redback is another cousin of the black widow L. It is native to Australia, but it has spread to New Zealand, Belgium, and Japan through grape exports.
The spider often builds nests and webs on grape leaves and inside bunches. The species is also found in urban areas, frequently making nests in human dwellings. The redback is identified by its prominent red stripe or hourglass-shaped mark on its black-colored back.
This mark is more noticeable on female redbacks than on males. Redback spiders are not aggressive and are more likely to play dead when disturbed, but a female spider defending her eggs is very likely to bite. Both male and female redbacks are venomous, but most envenomations primarily result from female bites. The venom is a mix neurotoxins called alpha-latrotoxins, which produces pain, sweating, rapid heartbeats, and swollen lymph nodes. The spider can moderate the amount of venom it injects, and the severity of these symptoms often depend on how much venom is delivered.
More than redback bites are treated each year in Australia, many with antivenin.
Researchers and physicians are split on the effectiveness of redback antivenin, with some studies indicating that it was not effective in treating symptoms or relieving pain. Nevertheless, the last human death attributed to redback envenomation occurred in This family of spiders in the order Araneida are named for their funnel-shaped webs, which open wide at the mouth of the tube.
The spider sits in the narrow funnel waiting for prey to contact the web.
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They are generally brownish or grayish with light and dark stripes near the head. Grass spiders construct a large sheet web with a funnel they use as a retreat. These webs are commonly built on the ground, around steps, window wells, foundations, and low shrubs. Habitat - These spiders are often called grass spiders because they construct their webs in tall grass, heavy ground cover and the branches of thick shrubs.
Rarely will a funnel web spider be seen indoors, except for an occasional wandering male. They are found mostly in the Pacific Northwest states. Mouse Spiders Venom toxicity - known to cause severe illness, especially to young children - similar to Red-Back Spider. Although normally not aggressive, the male mouse spider will bite if provoked, and should be considered dangerous to humans. It has large hard fangs which can cause a deep painful bite.
First aid and medical attention ambulance should be sought as soon as possible. The male Mouse Spider often has a bright red head and elongated fangs.
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Habitat - Mouse spiders are ground dwellers with burrows of more than 3 feet deep. The male often wanders about during the day on open ground, especially after rain, in search of females. Black House Spiders Venom toxicity - the bite of the Black House Spider is poisonous but not lethal. Certain people bitten experience severe pain around the bite site, heavy sweating, muscular pains, vomiting, headaches and giddiness.
Habitat - this spider spins a lacy, messy web and is prefers dry habitats in secluded locations. It is commonly found in window framing, under eaves, gutters, in brickwork, sheds, toilets and among rocks and bark. Electric lights attract their prey - moths, flies, mosquitoes and other insects.
Black Widow Spiders
Wolf Spiders Venom toxicity - the bite of the Wolf Spider is poisonous but not lethal. Although non-aggressive, they bite freely if provoked and should be considered dangerous to humans. The bite may be very painful. First aid and medical attention should be sought as soon as possible, particularly as to children or the elderly. The female carries it's young on its back. Habitat - this spider is a ground dweller, with a burrow retreat.
It has a roving nocturnal lifestyle to hunt their prey and can move very rapidly when disturbed. Commonly found around the home, in garden areas with a silk lined burrow, sometimes with a lid or covered by leaf litter or grass woven with silk as a little fence around the rim of the burrow. Trap-Door Spiders Venom toxicity - the bite of the Trap-Door Spider is of low risk non toxic to humans.https://cruacharenan.tk
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It is a non-aggressive spider - usually timid but may stand up and present it's fangs if harassed. Rarely bites - but if so it can be painful. The male has distinct boxing glove-shaped palps, that is, the two "sensory feelers" at front of its head. Habitat - this spider is a ground dweller, with a burrow retreat lined with silk of up to 10 inches in depth and around 1 inch in width - prefers nesting in drier exposed locations - often has a wafer-like lid on the burrow entrance. Trap-Door Spiders are commonly found in the drier open ground areas around the home.
Orb-Weaving Spiders Venom toxicity - the bite of Orb-Weaving Spiders is of low risk not toxic to humans. They are a non-aggressive group of spiders.
Seldom bite. Be careful not to walk into their webs at night - the fright of this spider crawling over one's face can be terrifying and may cause a heart attack, particularly to the susceptible over 40 year olds. The common Golden Orb-Weaver Spider has a purplish bulbous abdomen with fine hairs. Habitat - often found in summer in garden areas around the home - they spin a large circular web of 6 feet or more, often between buildings and shrubs, to snare flying insects, such as, flies and mosquitoes.
St Andrews Cross Spiders Venom toxicity - the bite of the St Andrews Cross is of low risk non-toxic to humans. The St Andrews Cross Spider usually sits, upside down, in the middle of its web forming a cross - as illustrated.