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Black Widow Spiders ...highly venomous - can be deadly


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Venom toxicity:- the Black Widow Spider can inflict a painful bite which can be fatal, especially to the young and elderly. An effective anti-venom was developed in 1956.


Only a small amount of venom can cause serious illness, as the poison attacks the nervous system. Systemic envenomisation usually results in headache, nausea, vomiting, abdominal pain, pyrexia and hypertension.


The pain around the bite area can be excruciating or it may go unnoticed. First aid and medical attention should be sought as soon as possible, if bitten. If you have heart condition or other heart problem, you may need hospitalization.


Spider Identification :- the body of an adult black widow is about 1/2 inch long. The female black widow is normally shiny black, with a red hourglass marking on the underside of the abdomen. The marking may range in color from yellowish orange to red and its shape may range from an hourglass to a dot.


Habitat : - prefers woodpiles, rubble piles, under stones, in hollow stumps, sheds and garages. Indoors it can be found in undisturbed, cluttered areas in basements and crawl spaces.




The spiders listed below have been known to cause death or give bites that are classed as dangerous or life threatening. However, there is an antivenin available for the Black Widow which is the spider most likely to have caused deaths in the United States. Click here for a map showing the location of some of the dangerous spiders found in the USA.



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Web Spinning Spiders :


Black Widow - Latrodectus mactans

The black widow is one of the most commercially popular spiders and is a favorite Halloween costume for trick-or-treaters here in the U.S. Widow spiders belong to the family of comb footed spiders (Family Therididae).  The female, about 1.3 cm (0.5 in) long, is glossy black, densely clothed with microscopic hairs, and marked with a characteristic red hourglass on the underside of the abdomen. The male, which is rarely seen, is smaller than the female and has four pairs of red marks along the sides of the abdomen. The Black Widow is found in the warmer regions in every state in the United States except Alaska; it lives in a variety of natural and domestic habitats. The venomous bite of the Black Widow Spider, causes muscle spasms and breathing difficulty in humans and may be fatal. Black Widows comprise about six species and inhabit most of the warmer regions of the world to a latitude of about 45 degrees N. The female black widow spider, though it is the most venomous spider in North America, seldom causes death as it injects a very small amount of poison when it bites. Reports indicate human mortality at well less than 1% from black widow spider bites.


For More Information click here to read the Wikipedia Article ..


Brown Widow - Lactrodectus geometricus


The Brown Widow is of the same group as the Red-back and the Black Widow but its toxin is about one-tenth the strength of the Red-back toxin and does not cause the same severe reaction. Brown Widow Spiders usually curl up into a ball, and drop to the ground as a primary defense. The Brown Widow Spider is one of the species with the infamous "red hourglass" marking on the underside of its abdomen. Only the females are dangerous when it comes to any species of widow spider. It is an introduced species in the United States and is found mainly in the tropical states. According to Dr. G.B. Edwards, an arachnologist with the Florida State Collection of Arthropods in Gainesville, the brown widow venom is twice as potent as black widow venom.  However, they do not inject as much venom as a black widow, are very timid, and do not defend their web.  The brown widow is also slightly smaller than the black widow.

Black Widow Spider Is Too Close For Comfort!


Handling a Female Black Widow Spider (Latrodectus mactans)


Spider brown widow (Latrodectus geometricus)

For more information read the Wikipedia article :


Hunting Spiders :


Brown Recluse - Loxosceles reclusa




The Brown Recluse spider (Loxosceles reclusa) is a member of the "brown" spider family, Loxoscelidae. They are light in colour and about 7mm long; their six eyes are arranged in two rows. They are easily identified by the distinctive dark violin-shaped design on its lighter upper abdomen. They are most common in the western and southern United States. A few species of Brown Recluse are harmful to man - including the brown recluse, which occurs in the United States and Chile. When bitten, a blister arises around the area of the bite. The local pain becomes intense with the wound sloughing tissue (loxoscelism) often down to the bone. Healing takes place slowly and may take 6 to 8 weeks. If the bite of a brown recluse spider is suspected, collect the spider and consult a physician immediately.


BROWN RECLUSE (Loxosceles reclusa)


Brown Recluse Spiders :


Here's some photos sent in by viewers.  The brown recluse belongs to a group of spiders that is officially known as the "recluse spiders" in the genus Loxosceles (pronounced lox-sos-a-leez). These spiders are also commonly referred to as "fiddleback" spiders or "violin" spiders because of the violin-shaped marking on the top surface of the cephalothorax (fused head and thorax). However, this feature can be very faint depending on the species of recluse spider, particularly those in the southwestern U.S., or how recently the spider has molted. The common name, brown recluse spider, pertains to only one species, Loxosceles reclusa. The name refers to its color and habits. It is a reclusive creature that seeks and prefers seclusion.


The brown recluse spider and ten additional species of Loxosceles are native to the United States. In addition, a few non-native species have become established in limited areas of the country. The brown recluse spider is found mainly in the central Midwestern states southward to the Gulf of Mexico. Click here for a map of the different species of Recluse and their distribution on the United States.  Isolated cases in Ohio are likely attributable to this spider occasionally being transported in materials from other states. Although uncommon, there are more confirmed reports of Loxosceles rufescens (Mediterranean recluse) than the brown recluse in Ohio. It, too, is a human-associated species with similar habits and probably similar venom risks (unverified). (Ohio State University Fact Sheet) A great reference page on Brown and Desert Recluse and their identification is here. Click here for an article by George Fiedler on one of the most common infections that is often mistaken for a recluse bite.


Here's how to identify a brown recluse:


1. Look at the color. A brown recluse has a dirt or sandy brown body with a slightly darker marking at its centre. Its legs are a lighter brown and completely uniform in colour, with no additional markings. If the spider has stripes or other pigments on its legs, it's not a brown recluse. If the spider has more than two pigments on its body, it's not a brown recluse. If the spider has legs that are darker than its body, it's not a brown recluse.


2. Examine the violin shape on the spider's body. It's a slightly darker brown color than the rest of the body, or cephalothorax. The violin shape isn't clearly defined, so it may not look to you exactly like the musical instrument. Many spiders have similar shapes on their bodies, so this alone is not significant enough to identify the spider as a brown recluse. Again, look at the colour of the violin shape closely. If it has spots of different pigments, then you are not looking at a recluse.


3. Look at the eyes if you can. Whereas most spiders have eight eyes, recluse spiders have six eyes that are arranged in pairs in a semicircle on the forepart of the cephalothorax .One pair is in the centre, and there's a pair on either side. Because the eyes are so small, it can be difficult to see them without a magnifying glass. If you count eight eyes, you're not looking at a recluse.


4. Look for fine hairs. The brown recluse has many fine, short hairs on its body. Unlike some other spiders, it does not have spines on its body or legs. If you see a spider with spines, it's definitely not a recluse.


5. Check the body width. The brown recluse's body doesn't grow to be larger than 1/2 inch. If you're looking at a spider that's larger than this, it's a different type of spider.



In the mature brown recluse spider as well as some other species of recluse spiders, the dark violin marking is well defined, with the neck of the violin pointing toward the bulbous abdomen. The abdomen is uniformly coloured, although the coloration can range from light tan to dark brown, and is covered with numerous fine hairs that provide a velvety appearance. The long, thin, brown legs also are covered with fine hairs, but not spines. Adult brown recluse spiders have a leg span about the size of a quarter. Their body is about 3/8 inches long and about 3/16 inches wide. Males are slightly smaller in body length than females, but males have proportionally longer legs. Both sexes are venomous. The immature stages closely resemble the adults except for size and a slightly lighter colour.


The brown recluse spider spins a loose, irregular web of very sticky, off-white to grayish threads. This web serves as the spider's daytime retreat, and it often is constructed in an undisturbed corner. This spider roams at night searching for insect prey. Recent research  indicates that the brown recluse spider is largely a scavenger, preferring dead insects. Mature males also roam in search of females. Brown recluse spiders generally occupy dark, undisturbed sites, and they can occur indoors or outdoors. In favourable habitats, their populations are usually dense. They thrive in human-altered environments. Indoors, they may be found in attics, basements, crawl spaces, cellars, closets, and ductwork or registers. They may seek shelter in storage boxes, shoes, clothing, folded linens, and behind furniture. They also may be found in outbuildings such as barns, storage sheds, and garages. Outdoors, brown recluse spiders may be found underneath logs, loose stones in rock piles, and stacks of lumber. The brown recluse spider is not aggressive, and it normally bites only when crushed, handled or disturbed. Some people have been bitten in bed after inadvertently rolling over onto the spider. Others have been bitten after accidentally touching the spider when cleaning storage areas. Some bites occur when people put on seldom used clothing or shoes inhabited by a brown recluse. (Ohio State University Fact Sheet)


For More Information you can read the Wikipedia Article :

Hobo Spider - Tegenaria agrestis 


The Hobo Spider is a moderately large spider  which was originally native to western Europe and was introduced into the north western United States (Port of Seattle) sometime before the 1930's. This large brown spider has a chevron pattern on the abdomen and is commonly seen running across floors. The Hobo is especially active July to September, when males search for females. Many bites previously attributed to the Brown Recluse Spider are now thought to be caused by the Hobo Spider. It is now acknowledged as being the leading cause of serious envenomation (tegenarism) in the northwestern United States. However not all bites result  in necrotic arachnidism in many cases the bites are "dry", and no venom is injected .

Brown Recluse Spider Facts. The Brown Recluse Spider Bite. TheCoolFactShow 




Hobo Spiders : venomous - dangerous?


Venom toxicity - although the bite of the hobo spider is initially painless, the bite can be serious. After 24 hours, the bite develops into a blister and after 24-36 hours, the blister breaks open, leaving an open, oozing ulceration. Typically when the venom is injected, the victim will experience an immediate redness, which develops around the bite. The most common reported symptom is severe headache. Other symptoms can include nausea, weakness, fatigue, temporary memory loss and vision impairment. In any case, first aid and medical attention should be sought, if bitten, as and when any adverse health effects are observed.


Spider Identification - they are brown in color and the adults measure roughly 1/3 to 2/3 inch in body length and 2/3 to 2 inches in leg span. Their abdomens have several chevron shaped markings. Males are distinctively different from females in that they have two large palpi (mouth parts) that look like boxing gloves. Females tend to have a larger and rounder abdomen when compared to males.


Habitat - they can be found anywhere in Washington, Oregon, Idaho, Montana, Wyoming, Utah and Colorado. They rarely climb vertical surfaces and are uncommon above basements or ground level.


CLICK HERE - FIRST AID - Hobo Spider Bite




The Hobo Spider


Broad Faced Sac Spider


The broad face sac spider, trachelas tranquillus,  is often confused with the woodlouse hunter, being similar in shape & colour. Its abdomen is more sac shaped howeverand is a light yellow/grey with a darker marking on thedorsal side. This is a hunting spider so it makes no web. However, it builds a sac like tube to hid and rest in diurnally which is also used to protect its eggs in autumn. This spider tends to forage on other dead arachnids and insects which can cause its bite to be particularly unpleasant due to infections.




Sac Spiders:




The venom of sac spiders contains a cytotoxin—which means it kills cells—like the venom of a brown recluse. Unlike brown recluse bites which can take 2-3 months to heal, most sac spider bites heal much more quickly, although the reaction will vary greatly from individual to individual. Typical symptoms of a sac spider bite include a stinging sensation followed by redness and mild swelling. In a few cases, the bite may blister and break, leaving a sore that can take several weeks to heal. Sometimes the person will feel mildly ill. Sac spiders belong to the genus Cheiracanthium and the family Clubionidae. They are quite small and easy to overlook—about 1/4 - 3/8 inch long, with no conspicuous markings. The front legs are longer than the other three pairs. Sac spiders are quite pale. A common house species, the yellow sac spider is pale greenish, tan or straw coloured. Other sac spiders are light brown. Sac spiders typically have darker mouthparts and a faint dark stripe running lengthwise down the abdomen. Normally, these are outdoor spiders, but sac spiders often invade structures. Their numbers increase significantly in the fall when the weather turns cool and their food supply disappears. If there are small insects available, sac spiders can become established indoors. At night, sac spiders actively hunt their prey—usually small insects. In search of prey, they run quickly waving their forelegs before them. Indoors, they can be observed on walls and ceilings, but drop to the floor to seek cover when disturbed. Sac spiders construct a silken tube or sac in a protected area, such as within a leaf, under landscape timbers or logs, or at the junction of a wall and ceiling, and they use this sac as their daytime retreat. This is how the sac spider gets its name. These spiders do not build webs. After mating, females lay 30 to 48 eggs and cover them in a thin coat of loosely spun silk. The small, white, paper-like sacs are often found in easily overlooked locations, along ceilings and corners, or behind pictures and shelves. The female may guard these egg sacs and may produce several egg masses during her lifetime. Inspect for sac spiders by looking for sacs in upper corners of rooms, ceilings, behind pictures, on window moulding, blinds or curtains. During the day, sac spiders may be inside these sacs so vacuuming is an excellent method of control. Remove and discard vacuum cleaner bags to prevent reinfestation.


For More Photos and information : 


Yellow Sac Spider - Cheiracanthium inclusum 

Yellow Sac Spiders are relatively small (10 mm body length), and are yellowish in color; they are difficult to distinguish from one another. Bites generally produce instant, intense stinging pain, not unlike that of the sting of a wasp or hornet. This may be followed by localised redness, swelling and itching; these manifestations may or may not evolve into a necrotic lesion, but when that occurs healing is usually complete within eight weeks. Side effects may include chills, fever, headache, dizziness, nausea, anorexia, and sometimes shock.


For More information and photos click here and or see information above 


Brazilian Wandering Spider - Phoneutria fera


The Brazilian Wandering Spider  are very fast, highly venomous, and extremely aggressive and is thought to be among the most venomous spiders known.  Recent studies however have found that it only injects venom in about one-third of its bites and may only inject a small amount in another third. Therefore the effects of the bites from this spider can range from only a couple of pin pricks to a full dose of its poison.  In South America, these spiders are often encountered in peoples' homes, hiding in  shoes, hats, and other clothes. It wanders the forest floor, which is how it got its name. The Brazilian Wandering Spider also is called the Banana Spider because there have been cases where these spiders have appeared on banana boats heading for the United States.




For More Information Read the Wikipedia Article :




Brazilian wandering SPIDER killer kills in 3 hours (subtitled Portuguese)-ARANHA-venenosa e mortal


Mouse Spider :


The mouse spider is 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. It is a medium to large spider of up to 1 and 1/2 inches in body length. The male Mouse Spider often has a bright red head and elongated fangs.  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.




For More Information :


Spider Spotlight - Missulena bradleyi - Mouse Spiders


Other Spiders as a pet .. Introduction and keeping 


Other spiders Species :  Common Australian Spiders  1   ...  2  ....  3


                                           Common United States Spiders and Americas  1   ...  2  ....  3


Other Spiders as a pet .. Introduction and keeping 


Other spiders Species :  Common Australian Spiders  1   ...  2  ....  3


                                           Common United States Spiders and Americas  1   ...  2  ....  3


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