- Brown Recluse Spider (Loxosceles reclusa)
- Brazilian Wandering Spiders (Phoneutria fera and P. nigriventer)
- Yellow sac spider (Cheiracanthium inclusum)
- Wolf spider (family Lycosidae)
- Black Widow Spider (Latrodectus mactans)
- Brown Widow Spider (Latrodectus geometricus)
- Red Widow Spider (Latrodectus bishopi)
- Redback Spider (Latrodectus hasselti)
- Funnel-web Spiders (family Dipluridae)
- Sydney funnel-web spider (Atrax robustus)
- Mouse spider (Missulena)
- Six-eyed sand spider (Sicarius hahni)
- Mediterranean Black Widow (Latrodectus tredecimguttatus)
A large variety of spider species is found in the world; so it is estimated that around 43,000 species exist. Out of such a large number, only few are Poisonous Spiders and out of that, one-tenth are responsible for the human’s death. Spider venom is much more dangerous for small creatures while on the other hand, because of its size it does not have a major affect on humans. However, it is a fact that venom of few spiders are also very dangerous for humans, as they can produce skin lesions in people and can produce allergic reactions that will ultimately result in fatalities. Many poison control centers and hospitals now have the species specific antivenin that helps to reduce spider bite-related deaths.
Awareness programs must be started in order to let people know what they should do when spiders bite them. Treating it at an earlier stage will help save their lives. In this article, the major species of poisonous spiders that are very harmful and can also cause fatalities will be discussed.
All spiders by their definition have a pair of fangs through which they can inject venom. The venom injected into a human being can cause many diseases and it wounds if the bite becomes infected; from there, it may cause death. Deaths related to spider bites are very rare, as most poisonous spiders are found in jungles and under the bushes, or other places like that where people do not often go. The main thing to observe is the species of the spider; that can help us decide if it is poisonous or not. Although it is very difficult for a common man, the details given below will let you know what the specifications, habitat and venom toxicity of various spider species are.To contents ↑
Brown Recluse Spider (Loxosceles reclusa)
Brown Recluse destroys the walls of the blood vessels and sometimes it causes skin ulcer. So this is the reason that it is considered as one of the most dangerous and poisonous spiders in US. It has also been found that the brown recluse spider’s venom effect Phospholipid molecules, which make up a huge portion of cell membranes. It transforms these molecules into simpler lipids. The injury caused by the spider bite will take many months to heal. As a result this wound may become infected and can even lead to death. This type of spider is also called violin spiders and is mostly found in the southern and western part of United States. They are almost about 7mm and have a leg span of 2.5 cm., making its home in the caves and it has now extended its range to the northern US. Storage areas, ceiling voids and walls are the most favorable places for this type of spider to make a place in.To contents ↑
Brazilian Wandering Spiders (Phoneutria fera and P. nigriventer)
Brazilian Wandering Spiders are found on banana leaves. They are also called banana spiders due to this reason. They raise their front legs straight up in the air as an aggressive defense posture. This is considered the deadliest spider all over the world as its venom directly impacts the nervous system. As a result it causes the symptoms of salivation, painful and prolonged erections and irregular heartbeat.
It is also a very poisonous spider as it is found on banana’s leaves, in which everyone wants to eat. In 2013, a family in England had to move out of their house in order to fumigate their house because it was infected with tiny Brazilian Wandering spiders. Egg pouch was delivered to their house in a banana bunch and unfortunately, the egg sac was broken. This allowed the potentially deadly contents to spread all over the house.
Yellow sac spider (Cheiracanthium inclusum)
Yellow Sac Spiders belongs to the Clubionids family of spiders that have a body length from 3 to 15 mm. They build silken tubes in the leaves, grass or under stones. It is found throughout the United States, South America and also in Mexico. Its venom can produce necrotizing lesions but the good news is that it occurs rarely in bite victims. Swelling in the bite area and redness are the frequent reactions of this spider’s bite. Moreover, they are also not docile creatures, which mean that only the female yellow sac spider may bite humans in defense of her eggs.To contents ↑
Wolf spider (family Lycosidae)
This type of poisonous spider belongs to the family of Lycosidae. They have this name due to their ability of chasing and running after their prey. They are found in North America and in Europe. Several of its species are also found in the Arctic Circle. They are dark brown in color, have hair on their bodies and are long and broad with long legs. They have hairy skin and can grow up to a size of 35 mm. Some of this species have the ability to spin their webs as well. Wolf spiders being large in size and being able to move very fast cause fear in human residencies. Their eggs are contained in grey colored silk sag. Wolf spiders are not considered to be aggressive and bite humans in their own defense. Their bites are poisonous, but not very dangerous. Symptoms of its bite include nausea, dizziness and fast heartbeat. Wolf spider’s bite immediate symptoms are similar to those of a bee sting. Its painful bite gives a panicking experience to the victim. They have unique parenting habits, which are of interest to scientists. This spider has a nocturnal lifestyle to hunt their prey; it can move very quickly when something disturbs them. They are commonly found around the garden or in the hime around the silk-lined burrow.To contents ↑
Black Widow Spider (Latrodectus mactans)
Black widow spider is one of the most common poisonous spiders causing harm to victims. It is found in the United States and several parts of Canada, spreading across Latin America and the West Indies. It has the ability to make its habitat in several places, such as in woodpiles, burrows, and in plantations. The female Black Widow is mainly seen, as most of the males are eaten up by the female. The male and female have different appearances. Female black widows have a distinctive color of shiny black and are about 1.5 inches long. Males have a size of about half of that of females. Their main food is insects, which get trapped in their webs. Its bite though produces simple pinprick, but has severe symptoms. Symptoms include muscle pain, cramping, nausea, and mild paralysis of the diaphragm, causing breathing difficulties. The recovery rate from this spider bite is very fast. No serious complications through its bite have been reported and no deaths have occurred in United States.To contents ↑
Brown Widow Spider (Latrodectus geometricus)
The brown widow spider is another poisonous spider. It was first established in southern California in 2000, but has evolved in Africa. It has been rapidly spreading in Florida and the main cause of its expansion has been transportation through vehicles. These are hard to recognize compared to black widow spiders, as their color varies from light tan to dark brown and are found with black color too. They also have different colored markings on their skin of black, white, yellow, orange, or brown color on their abdomen. It has a unique egg sac with a globe like shape and pointed projections. This poisonous snake makes its habitat in protected areas, especially near our homes in presence of human beings. It is an aggressive spider and its bite is usually unintentional, such as when being pressed against your skin.To contents ↑
Red Widow Spider (Latrodectus bishopi)
This poisonous spider also has the name ‘Red-legged widow’. This spider is different from other spiders in appearance by having a reddish brown to black colored abdomen. The underside of their abdomen has a red spot and the top is of red or orange color surrounded by yellow or white outline. Male legspan is one-third of a female. Their current habitat is in scrublands in Central and Southern Florida, but according to some experts, this range of habitat is defined as widening. The main feed of this spider is insects. It is known to be non-aggressive towards people. It usually bites when it is protecting its eggs or become attached to people’s skin or footwear. The symptoms of its bite include pain, nausea, and cramping, similar to those of a black widow. People who are less immune to diseases and have greater chances of catching health diseases are more likely to be bitten by this spider. Cleanliness is the key to keep yourself safe from these poisonous spiders.To contents ↑
Redback Spider (Latrodectus hasselti)
Redback is another poisonous spider belonging to the family of the black widow spider. It was first found in Australia, but has now spread across Japan, Belgium, and New Zealand. It can survive in a wide variety of climates across all Australia except in hottest deserts and mountaintops. The root cause of its spread has been through grape exports. Moreover, it is also commonly found in areas where humans reside. This spider has a unique appearance and can be easily recognized by having a red stripe or hourglass shaped mark on its black-colored back. They are not aggressive and are likely to bite when being disturbed. Female Redback are likely to bite when protecting their eggs. The symptoms of their bite include pain, sweating, fast heartbeat and swollen lymph nodes.To contents ↑
Funnel-web Spiders (family Dipluridae)
These spiders are found in southeast Australia, mostly around Sydney. This species of poisonous spiders as evident from its name has funnel-shaped webs. These webs open wide at the mouth of the tube. In order to catch its prey, it sits on the funnel web and waits for the prey to come there. Once the prey/insect gets trapped in the web it can easily eat it. Funnel web spider bites are very painful and usually cause itchiness in the mouth or lips for a few minutes. There are many symptoms of this spider’s bite affecting your ear, nose, throat, heart, lungs, nervous system, and skin.mAs these spiders are extremely poisonous when bitten, one is required to seek immediate medical attention.To contents ↑
Sydney funnel-web spider (Atrax robustus)
It is a large poisonous spider. They have shiny, dark brown to black color. They can be easily identified by having a glossy black head and a dark brown or purplish colored abdomen. In addition to this, they have fine hairs covering their legs and body. They are found in New South Wales, from Newcastle to Nowra and west to Lithgow. They usually prefer to make their habitats in damp and shady places in urban areas and forests. Natural habitats include closed forests. Their diet includes insects and small lizards. They form burrows under rocks to reside in. These spiders are very aggressive in defending themselves. Their venom is very poisonous and should be taken out immediately of human bodies when bitten, as the venom causes great damage to the nervous system and in extreme cases, may also result in death of a human. One permanent method to get rid of these poisonous spiders is to remove all the vegetations and plantation causing them to breed. Only killing the existing spiders by spraying will only provide a short term solution.To contents ↑
Mouse spider (Missulena)
The Mouse spider is another poisonous spider found in Australia. It is one of the twelve eight species of mouse spider in Australia. They have huge fangs and a deadly poison similar to that of a Sydney Funnel-web spider. Their size varies from 10mm to 35mm. This spider can easily be recognized by its shape and color. They have high, bulbous heads and jaws, smooth and shiny carapace and long, slim pedipalps. They are mostly black-colored. Their main habitat is in mainland Australia in forest areas. The symptoms of a Mouse Spider bite are similar to those of Funnel-web spiders and thus require immediate medical assistance and first aid treatment. This species or spider is usually not found in densely populated urban areas.To contents ↑
Six-eyed sand spider (Sicarius hahni)
This poisonous spider, as evident from the name has six eyes and eight legs and is found in the deserts of Southern Africa. Its scientific name is ‘Sicarius hahni,’ which literally means a murderer, and the spider is literally a deadly murderer indeed. Its venom is one of the most deadliest ones. Most of the spiders of this species have reddish brown to yellow color and no distinct patterns. Their body is covered in small hairs called ‘setae’. These spiders have a unique ability to camouflage themselves according to the color of their habitat in sand. The bite of this spider is usually accidental. It hunts its prey by a surprise attack and instead of digging a burrow to reside, it buries itself under the sand. It does not search for its prey deliberately, but waits for an insect nearby. It is one of the shyest spiders and at the same time, has poisonous venom. The six-eyed sand spider rarely comes in contact with humans and even when it does, it rarely bites. Moreover, unlike other spiders, it does not transmit small amounts of venom in every bite, but instead a large amount in just one bite. The venom causes blood vessels to leak and destroys human flesh.To contents ↑
Mediterranean Black Widow (Latrodectus tredecimguttatus)
It is one of the most poisonous snakes found and is a species of widow spiders. It is mostly found throughout the Mediterranean Region as evident by the name too. This region starts from Portugal and spreads across southwest and Central Asia. It is black in color, with about thirteen spots found on the abdomen. These spots are usually in red color, but may be in yellow or orange color. Mediterranean black widow mainly lives in grasslands and steps. One of its main breeding grounds includes areas where grain is planted. The female spider is bigger in size than the male spider. An astonishing feature about this spider is that the female bite can only harm humans as the male bite cannot enter the epidermis of human skin. Furthermore, its bite is extremely painful as well and in certain cases, can prove to be to be very dangerous for human lives. Over time, it has been seen that these types of spiders have remained far from areas where humans live. Thus, they have had very few chances of interaction with humans. Few cases of humans being bitten by the Mediterranean Black widow have been reported.
All the above described poisonous spiders are very dangerous for humans and one must take great care in order to protect his/her life. Taking precautionary measures is much better rather than treatment afterwards. One should that be knowing what type of poisonous spiders may be in their surroundings and what their favorable places are. In this way, they can easily take measures to live their life more easily.