9. Brown Recluse Spider

Photo: mothernaturesinc

Brown recluse spiders are one of the most dangerous spiders in the United States. Its venom destroys blood vessel walls near the bite site, sometimes causing large skin ulcers. Research in 2013 revealed that a protein in spider venom targets phospholipid molecules, which make up a large portion of cell membranes, and converts them into simpler lipids. The wound created may take several months to heal or may become infected, leading to the victim’s death.

Most brown recluse spiders live in the Western and Southern United States. They measure about 7 mm (0.25 inches) and have a leg span of about 2.5 cm (1 inch). The front half of the brown recluse spider’s body has a dark violin-shaped design, the “neck” is formed by a conspicuous groove in the midline of the back. This spider has expanded its range into the northern regions of the United States, nesting in caves, rodent nests and other hiding places. Brown recluse spiders can also nest in inconspicuous areas of the home, such as attics, sheds or voids in walls or ceilings.

8. Brazilian wandering spider

 These spiders are sometimes called banana spiders because they are commonly found on banana plants. They take an aggressive defensive stance, by raising their front legs straight up in the air. The Brazilian wandering spider is very poisonous and is considered the most dangerous spider in the world. Their venom is toxic to the nervous system, causing symptoms such as salivation, irregular heartbeat, and prolonged, painful erections (priapism) in men. Scientists are studying P. nigriventer venom as a possible treatment for erectile dysfunction.

At the end of 2013, a family in London, England, had to move out of their house to have it disinfected because the house became home to Brazilian wandering spiders. A nest of this spider’s eggs was in a bunch of bananas that this family bought home from a convenience store. The spider egg nest then bursts and releases dozens of potentially deadly baby spiders.

7. Yellow-coated poisonous spider

Photo: wikipedia

Yellow-coated venomous spiders belong to the Clubionids family, a family of spiders (order Araneida) with a body length of 3 to 15 mm (about 0.12 to 0.6 inches), they often spin webs under stones, in leaves or in the grass. They are found throughout the United States, as well as in Mexico south through South America.

The venom of the yellow-coated tarantula is a cytotoxin (a substance that destroys cells or impairs their function) and can produce necrotic lesions, however such lesions rarely occur in humans. The victim was bitten. However, common reactions are redness and swelling at the site of the bite. Yellow-coated poisonous spiders are not gentle creatures, they are ready to bite if someone touches their nest or children.

6. Wolf spider (family Lycosidae)

Photo: spencerpest

Wolf spiders belong to the family Lycosidae, a large and widespread group found throughout the world. They are named after their wolf-like habit of chasing and pouncing on prey. There are about 125 species of wolf spiders occurring in North America, about 50 species in Europe. Many species occur north of the Arctic Circle. The largest have a body about 2.5 cm (1 inch) long and legs of about the same length. Most wolf spiders are dark brown in color, have hairy bodies, are long and wide, and have long, stubby legs. They are noted for their incredible running speed and often appear in grass, under rocks, logs or fallen leaves. Most wolf spiders build tubular, silk-lined nests in the ground.

Wolf spider eggs are contained in a grey silken sac that is attached to the female’s serration or silk-producing organ, giving her the appearance of pulling a large ball. After hatching, the baby spiders ride on their mother’s back for several days.

Although the wolf spider is not very aggressive, it often bites people in self-defense. Wolf spiders are venomous but the bite is not too dangerous. However, some victims who are allergic to spider bites in general may experience nausea, dizziness, and increased heart rate. The spider’s large fangs cause physical trauma at the site of the bite. The bite itself is described as similar to a bee sting. The venom from the spider bite can cause pain and itching on the spot. Along with its speed and scary appearance, the wolf spider can make the victim nervous. and panic after being bitten.

5. Black widow spider

Photo: bugmanpest

Black widow spiders are responsible for more than 2,500 poisoning cases each year in the United States. In addition to the United States, they are also found in Canada, Latin America and the West Indies. Black widow spiders are the most common species of the Latrodectus family in North America, building their nests in a variety of places, such as in woodpiles, in burrows, or in different plants.

Females will be glossy black and often have a red to yellow hourglass shape on the underside of their abdomen. Sometimes there will be two small triangles instead of a complete hourglass. Their bodies are about 2.5 cm (1 inch) long. Males are rarely seen as they are usually killed and eaten by the female after mating (hence their name black widow spider), males are about 1/4 the size of females. In addition to the hourglass shape, males also often have a pair of red and white stripes on both sides of the abdomen.

Black widow spider bites feel like pins and needles on the skin, often causing severe muscle pain and cramps, nausea and mild paralysis of the diaphragm, causing difficulty breathing. Most victims recover without serious complications. The bite of a black widow spider is said to be fatal to young children and the elderly.

4. Brown widow spider

Photo: earth.com

Brown widow spiders are thought to have evolved in Africa, but the first ones discovered came from South America. It is classified as an “invasive species” in the world. Populations of brown widow spiders have now appeared in southern California, the Caribbean, the Gulf states of the United States, as well as in Japan, South Africa, Madagascar, Australia and Cyprus. They nest in buildings, inside old tires and under cars, as well as among bushes and other vegetation.

Brown widow spiders have a brown appearance, ranging from dark brown to a dark brown that is almost black. Some animals’ bellies have dark brown, black, white, yellow or orange markings. Unlike other members of the genus, the hourglass-shaped underbelly of the brown widow spider is orange.

The venom of the brown widow spider is considered to be twice as potent as that of the black widow; however, this species is not aggressive and injects only a small amount of venom when biting. Brown widow bites were linked to the deaths of two people in Madagascar in the early 1990s.

3. Red widow spider

Photo: bugguide

This is the third widow spider on the list. The appearance of this spider is distinguished from other widow spiders by its red head and legs as well as its reddish brown to black abdomen. Many have red marks on the underside of the abdomen, which can be hourglass shaped, triangular or unclear. The upper part of the abdomen is spotted with red or orange spots, each surrounded by a yellow or white border. The leg span of adult females is 1.5-2 inches, while males are only about 1/3 that size.

Currently, red widow spiders inhabit areas with many palm trees in central and southern Florida; however, some experts believe this range may be expanding. This spider feeds on insects and is not considered aggressive towards humans. However, it will bite while protecting eggs or when caught on clothing or shoes. Red widow bites are similar to black widow bites and often result in identical symptoms (pain, cramps, nausea, etc.). Likewise, death from a red widow bite is quite rare because it injects only a small amount of venom when biting. Young children, the elderly and people with health problems are most susceptible to red widow spider bites.

2. Redback spider

Photo: australian.museum

The redback spider is a cousin of the black widow spider L. mactans; however, this species is not common. It is native to Australia, but it has spread to New Zealand, Belgium and Japan through grape exports. (Redback spiders often build nests and webs on grape leaves and inside grape clusters.) They are widespread throughout Australia, living in all of the continent’s diverse environments, except the hottest deserts and icy mountain peak. They are also found in urban areas, frequently nesting in human habitations. They possess prominent red stripes or hourglass-shaped markings on their black backs. This sign is more noticeable in females because their backs will be redder than in males.

Redback spiders are not aggressive and are more likely to play dead when disturbed, but female spiders guarding their eggs will likely bite. They also bite if they crawl into shoes or clothing and come into contact with a person’s skin while they are wearing clothes. The red backs of both male and female spiders are venomous, but most bites are from the female. Only 10-20% of bite victims are poisoned.

The redback spider’s venom is a mixture of neurotoxins called alpha-latrotoxin, which causes pain, sweating, increased heart rate and swollen lymph nodes. The redback spider can moderate the amount of venom it injects, the severity of these symptoms often depends on the amount of venom determined by the spider. Each year in Australia up to 250 redback spider bites are treated. The last death due to redback spider venom occurred in 1956, and since then there has been no other case.

1. Funnel-web spider

Photo: bhg.com.au

Funnel-web spiders belong to the Dipluridae family. They are named after the spider web they spin is funnel-shaped. The spider will lie in a narrow funnel waiting for its prey to come into contact with the spider web, then it will rush out and catch the prey at the mouth of the funnel. Floating limbs The most famous of these species are Evagrus, Brachythele and Microhexura in North America, Trechona in South America and Atrax in Australia.

Atrax robustus and A. formidabilis are large, bulky brown spiders that are feared in southern and eastern Australia because of their venomous bites. Several human deaths from bites from this aggressive spider have been recorded in the Sydney area since the 1920s. Today, an antidote made from the poison has been invented. It is in their venom that the medicine will be effective if the victim is given it immediately after being bitten.