There are at least 50,000 spider species in the arachnid family. Spiders are defined as having eight jointed legs, no wings, no antennae and only two body sections: the thorax and the abdomen. Spiders spend their entire life span capturing and eating other insects (about 2,000 in a year). Even though spiders do a great deal of good for our environment, spiders are greatly feared by most of the population. Most spiders are killed only because they scare people, not because they are actually dangerous to humans.

All spiders have some amount of venom with varying degrees of potency. The fangs of a spider are hollow. The venom is injected through the fangs into the victim (usually an insect). The venom will rapidly paralyze the victim and aid in digestion. Fortunately, most spiders are not dangerous to humans because their fangs are either too short or too fragile to penetrate human skin.

Spiders do not attack in herds. Spiders do not lay in wait and attack people. Spiders do not lift the covers at night and crawl into bed to bite people as they are sleeping. Some spiders can jump but they are not intentionally jumping at humans to attack them. A spider generally bites a human because it was scared and bites to defend itself. Spiders generally prefer to live in undisturbed areas such as corners of the house or the eaves or in the garden where they can catch insects in peace.

Killing spiders with pesticides is difficult. Spraying surfaces is usually ineffective because the spider has minimal contact with the sprayed area. The actual spider or egg sacs must be sprayed with pesticide. The danger of a possible spider bite has to be weighed against the risk of over-using pesticides that probably will not work against spiders.

Bite marks from most spiders are usually too small to easily be seen. Frequently the patient will not recall being bitten. Many of the spider bites will result in pain, small puncture wounds, redness, itching and swelling that lasts a couple of days. Spiders rarely bite more than once, so multiple bites are usually caused by insects such as fleas, bedbugs, ticks, mites and biting flies.

Black widow spider

Black widow spiders generally live in trash, closets, attics, woodpiles, garages and other dark places. They are found throughout California, especially in the warmer regions such as the Central Valley and Southern California. Only the female spider is dangerous to humans.

What does a black widow spider look like?
The black widow spider is a shiny, inky black spider with a large round tail segment (abdomen). Including its legs, the black widow generally measures from one-half inch to one inch in length. Red to orange-colored markings, usually in the shape of an hourglass, are found on the underside of the belly.

What are the symptoms of a bite?
A black widow spider bite gives the appearance of a target, with a pale area surrounded by a red ring. Severe muscle pain and cramps may develop in the first two hours. Severe cramps are usually first felt in the back, shoulders, abdomen and thighs. Other symptoms include weakness, sweating, headache, anxiety, itching, nausea, vomiting, difficult breathing and increased blood pressure. Young children, the elderly and those with high blood pressure are at highest risk of developing symptoms from a black widow spider bite.

How dangerous are black widow spider bites?
If a black widow spider bites a person, do not panic! No one in the United States has died from a black widow spider bite in over 10 years. Very often the black widow will not inject any venom into the bite and no serious symptoms develop. Wash the wound well with soap and water to help prevent infection.

If muscle cramps develop, take the patient to the nearest hospital. Some victims, especially young children, may be admitted overnight for observation and treatment. There is treatment for a black widow spider bite that can take care of the symptoms. Various medications are used to treat the muscle cramps, spasms and pain of a bite. Black widow spider antivenin is seldom necessary.

Brown recluse spider

What does a brown recluse spider look like?
Named for its habit of hiding in dark corners, the brown recluse spider (Loxosceles reclusa) is also known as the violin spider or fiddleback spider because of a violin-shaped marking. The brown recluse spider is about a half-inch long (including legs) and is a solid light brown color. The violin marking is configured with the base of the violin beginning at the eyes and the neck of the violin pointing toward the "waist." The violin marking is difficult to see clearly. Two other features can help identify the brown recluse: it has six eyes rather than the typical eight and the tail-end segment has no markings. If you see a brown spider with markings on the tail end, it cannot be a brown recluse spider. Any markings, patterns or spots on the tail end of a spider immediately eliminates the possibility that it is a brown recluse spider. It is, instead, one of dozens of brown spiders that live in houses and yards. They may bite, but they are not dangerous.

Where do brown recluse spiders live?
Spider experts across the state agree that the true brown recluse spider does NOT live in California, but is native to Kansas, Texas, Oklahoma and Mississippi. There are some related species found in California. The Loxosceles laeta, imported from South America, has been found in eastern Los Angeles County. The Loxosceles deserta is found in the Mojave and Sonoran deserts, the foothills of the Central Valley up to Merced and Fresno counties, but not in Northern California.

In any case, the brown recluse is called a "recluse" because it hides and is not commonly found out in the open. The brown recluse will hide in dark, quiet, out-of-the-way areas where it will not easily be disturbed.

What are the symptoms of a brown recluse spider bite?
The brown recluse spider bite usually causes some pain or burning in the first 10 minutes, accompanied by itching. The wound takes on a bull’s-eye appearance, with a center blister surrounded by an angry-looking red ring and then a blanched (white) ring. The blister breaks open, leaving an ulcer that scabs over. The ulcer can enlarge and involve underlying skin and muscle tissue. Pain may be severe. A generalized red, itchy rash usually appears in the first 24-48 hours. Other symptoms include fever, chills, nausea, vomiting, muscle aches and hemolytic anemia (a condition where the red blood cells are destroyed).

People bitten by an unseen spider sometimes blame the brown recluse spider because their bite resembles a brown recluse spider bite. However, there are a number of other spiders and insects, as well as other medical conditions, that are capable of producing tissue wounds of similar appearance, but these are usually of a lesser severity.

What is the treatment for a brown recluse spider bite?
Treatment consists of washing the wound and applying an antibiotic ointment. The victim should seek medical attention if there are signs of an infection, an ulcer that does not heal, a bite accompanied by nausea, vomiting, fever or a rash. There is no special treatment or medication used to treat a brown recluse spider bite. If infection develops, antibiotics are used. If a wound becomes deep and infected, occasionally surgery is needed. Anytime there is a bite or a wound that is not healing and getting worse, see a physician for evaluation. 

Chronic arachnidism
or necrotic arachnidism

While most spider bites are not dangerous, there is a group of spiders that can produce bite wounds that look similar to a brown recluse spider bite. Unless the spider was actually seen, captured and brought to the physician, the brown recluse spider is not likely to be the culprit. Some of the spiders in this group that can cause a nasty bite include the running spider, jumping spider, wolf spider, tarantula, sac spider, orbweaver spider and the northwestern brown spider, also known as the hobo spider.

What are the symptoms of a bite from these kinds of spiders?
In most cases of bites from these spiders, there is pain or burning at the bite site in the first 10 minutes. The bite from this group is usually described as looking like a "target" or "bull’s-eye." The center of the wound is usually a blister surrounded by a reddened area. A pale or blanched area may surround the discolored reddened area. The blister may rupture, leaving an open ulcer. In severe cases the ulcer can become deep and infected causing tissue breakdown or tissue death (necrosis).

Worsening pain, itching and a burning sensation develop. A patient may also have symptoms such as a red, itchy rash over the torso, arms and legs that is usually seen in the first 24-72 hours. Patients may have pain in the muscles and joints, fever, chills, swollen lymph nodes, headaches, and nausea and vomiting.

How are these bites treated?
Frequently, when people with spider bites call the Poison Center, they think there is some special treatment that is necessary for their bite. There is no specialized therapy other than treating the symptoms. Most importantly, keep the wound clean to prevent infection. If the wound does not heal or does develop an infection, see your physician. Do not wait days and weeks while the wound continues to get worse.

There are tales of people having limbs amputated after spider bites. These involve people who refused to see a physician even though they had massive wounds that did not heal and became grossly infected. A wound that may have been originally treated with simple oral antibiotics, but left untreated, may require surgical intervention in extreme cases.

What else can cause a nasty looking wound?
Kissing bugs, fleas, bed bugs, flies, mites, wasps, ants and blister beetles have produced lesions similar to a brown recluse spider bite. Many skin disorders and medical conditions can produce lesions that can also mimic a brown recluse spider bite. Some of these include infected herpes outbreaks, bedsores, diabetic ulcers, poison oak and Lyme disease. Again, use common sense: If there is a wound that is not healing as expected or getting worse, see a physician.

Jumping spiders

The jumping spider is probably the most common biting spider in the United States. People are caught by surprise and scared when they see the spider jump, especially if it jumps towards them. Bites from a jumping spider are painful, itchy and cause redness and significant swelling. Other symptoms may include painful muscles and joints, headache, fever, chills, nausea and vomiting. The symptoms usually last about 1-4 days.

Wolf spiders

Wolf spiders are commonly found in California. They are large hairy spiders, up to 3-4 inches across. They are a mottled gray-brown color, which helps them hide in sand, gravel, leaves and other debris. Female wolf spiders carry their young on their backs. Except for one group, wolf spiders do not spin webs. They tend to burrow into the earth and hide. They are aggressive, come after their prey and are fast runners. Because of their impressive size and aggressiveness, wolf spiders can easily incite panic.

Bites from a wolf spider can cause pain, redness and swelling. The large jaws/fangs can cause a tear in the skin as they bite. Swollen lymph glands may develop. The skin area at the bite may turn black. Swelling and pain can last up to ten days.

Tarantulas

Tarantulas are also large hairy spiders. In fact, some people call any large hairy or fuzzy spider a tarantula. Tarantulas are very hairy with sharp bristles. The hairs are easily shed or can be rubbed off. Handling a tarantula can result in irritation to the skin. If hands are not washed after handling a tarantula and eyes are touched, the sharp hairs can cause eye irritation that may require a trip to the physician.

Tarantulas are sensitive to vibrations and hunt at night by touch. If cornered, the tarantula will make a purring sound and may rear up on its back legs. Even though tarantulas are scary looking to most people, most bites do not produce any significant poisoning symptoms. However, the bites can be quite painful because of the large size of the spider.

Wash your hands well with soap and water after handling a tarantula.

Northwestern brown spider or the hobo spider

The northwestern brown spider or hobo spider (Tegenaria agretis) is well known in Oregon and Washington and is also quite common in Utah. Spider bites by this spider are becoming recognized more often in California, which may be due to the fact that the spider is becoming better known. The hobo spider often causes a bite that leaves an open, slow-healing wound. Bites from this spider are frequently and mistakenly thought to be brown recluse spider bites.

Keep the wound clean and prevent infection. If the bite becomes infected or does not seem to heal, see a physician.

Daddy longlegs spiders

The Daddy Longlegs is not a true spider in that it cannot make silk and does not have fangs or venom glands. Daddy Longlegs have long thin legs with flexible claw-like "fingers". Daddy Longlegs can pinch but rarely penetrate human skin.

They have scent glands on the front part of their bodies that can give-off a bad-smelling fluid. This stinky fluid is used as a defense mechanism to keep enemies away. Some people might have a reaction to the fluid but Daddy Longlegs are not considered dangerous to humans.

Daddy Longlegs are usually found hanging upside down in corners, eaves or basements. They are very common and are found in most homes. Because they eat insects and other spiders, they are considered beneficial.

for more information on Brown Recluse Spiders…
by University of California Pest Management

Common Name: Southern black widow spider
Scientific Name: Latrodectus mactans Fabricius
Order: Araneae

Description: The body of the female, consisting of two regions (cephalothorax and abdomen), is typically shiny black with red markings. The red is usually an hourglass-shaped mark on the underside (venter) of the abdomen, but this may be reduced to remnants. Usually there is a single red spot just behind the spinnerets, sometimes a row along the back. There is much variation in body color with southern and western specimens being more strikingly marked than northern and eastern ones. The male has the abdomen narrower, with white lines along the sides which is shown by immatures as well. Young spiderlings are orange and white, and acquire more black in later developmental stages (instars) until some have little or no red except the hourglass markings. Immatures have the abdomen gray with white curved stripes. The body length of the female is about 3/8 inch and that of the male is about 3/16 inch, but sizes within different geographical populations can vary widely.

There are more than 25 Latrodectus species world wide. Contrary to common belief, the female does not consume the male in most situations, except when held together in cages from which the male cannot escape. Examination of the genitalia is the proper way to identify species in this group. The species in Texas can be separated to some degree by the shape of the red markings on the abdomen and the location.

The western black widow, Latrodectus hesperus Chamberlin & Ivie, usually has the hourglass marking connected or complete with the anterior triangle larger and wider than the posterior triangle. This species largely displaces the southern black widow in the western half of the state. In southwestern Texas through the Lower Rio Grande Valley and adjoining parts of Mexico, specimens of L. hesperus have been found in which the adults retain their brilliant immature colors. Further west, the coloration of the species appears to grade back to black.

The northern black widow, Latrodectus variolus Walckenaer, usually has the hourglass divided, typically with red spots on the dorsum and white lines on the sides. This species occurs throughout much of the eastern half of the U.S.

The brown widow, L. geometricus C. L. Koch, is dark to light brown with a pattern and an orange hourglass. They are sometimes called "gas station spiders" because of their habit of building webs in service stations. They are extending their range from the east but their presence in Texas is uncertain.

Life Cycle: Adults of both sexes have been found throughout the year in buildings. They can be very common at some locations and times. During the course of a summer a female may lay several egg sacs. The egg sacs are white to tan or gray, pear-shaped to almost globular of tough papery texture, about 1/4 to 1/2-inch in diameter. Each egg sacs contain from 25 to 400 or more eggs. Egg sacs are suspended in the web where the female stands guard nearby. The second stage (instar) spiderlings typically emerge about 4 weeks after egg sac production. Newly emerged spiderlings are not cannibalistic until 10 to 14 days after emergence, whereupon they may suddenly become highly cannibalistic. Males generally require fewer molts to mature than females.

Habitat, Food Source(s), Damage:  Widow spiders feed on a wide variety of arthropods. Red imported fire ants have been reported as their main food in cotton fields of East Texas. Boll weevils, grasshoppers, June beetles, and scorpions are also known prey. They are found in houses, outhouses, cotton fields, trash and dumps. Webs are commonly found in spaces under stones or logs, or holes in dirt embankments, and in barns, rural privies, and other outbuildings. The web is an irregular mesh usually built in a dark spot sheltered from the weather. The webs may also have a retreat, typically a 1/16 to 5/16 inch (2 to 8 cm) circular or semicircular silken tent. The spider spends most of the time in the retreat, venturing out onto the web for web maintenance or when attracted by prey vibrations. Webs are usually placed low to the ground.

Pest Status: Most notorious of all spiders in the United States; venom is highly virulent, but the spider is quite timid. Even when disturbed in its web it attempts to escape rather than to attack. Widow spiders are known from every state (except Maine where it undoubtedly also occurs) and several Canadian provinces. It is uncommon in the north but quite abundant in the south and west.

Just Plain Weird Stories

Solpugid Eremobates sp. Small Western U.S. species; much larger Near East species are called "camel spiders" but are not spiders. (from a photo by Ken Davis) Click image to enlarge

Myth: In the deserts of the Near East, there are "camel spiders" that anaesthetize sleeping humans and eat large chunks of their flesh.

Fact: This legend is widespread in Arab countries but was unknown in North America until it was disseminated by Gulf War veterans and repeated by the uninformed narrator of a TV documentary. Since this section was originally written, a much more extensive body of "camel spider" legends has arisen from the Iraq war; the newer ones are discussed in the next section.

"Camel spider" is a common name for solpugids, large non-spider arachnids found in desert regions. Solpugids (possibly excepting one species in India) have no venom, not even an anaesthetic, nor any means of delivering a venom even if they had any, and are strictly predatory on smaller creatures.

A number of soldiers have written me claiming this legend is, nonetheless, true. But not a single one has been able to supply the name, rank and serial number of any victim - or even just a name! It always happened to "a friend," the friend never has a name, and no matter how far down the line you follow the story, that elusive named person is always at least one "friend" away. That’s how urban legends work.

Solifugae is an order of Arachnida, containing more than 1,000 described species in about 140 genera. The name derives from Latin, and means those that flee from the sun. The order is also known by the names Solpugida, Solpugides, Solpugae, Galeodea and Mycetophorae. Their common names include camel spider, wind scorpion, sun scorpion and sun spider.

Solifugae are not true spiders, which are from a different order, Araneae. Like scorpions and harvestmen, they belong to a distinct arachnid order.

A Solifugid

Most Solifugae inhabit warm and arid habitats, including virtually all deserts in both the Eastern and Western Hemispheres, excluding Australia^[1]. Some species have been known to live in grassland or forest habitats. The most distinctive feature of Solifugae is their large chelicerae. Each of the two chelicerae are composed of two articles forming a powerful pincer; each article bears a variable number of teeth. Solifugae also have long pedipalps, which function as sense organs similar to insects’ antennae and give the appearance of the two extra legs. Pedipalps terminate in eversible adhesive organs. These are used to capture flying prey, and for climbing. They stridulate with their chelicerae, resulting in a rattling noise^[1].

Solifugae are carnivorous or omnivorous, with most species feeding on termites, darkling beetles, and other small arthropods, although Solifugae have been videotaped consuming larger prey such as lizards. Prey is located with the pedipalps and killed and cut into pieces by the chelicerae. The prey is then liquefied and the liquid ingested through the pharynx. Although they do not normally attack humans, these chelicerae can penetrate human skin, and painful bites have been reported.^[1]

Reproduction can involve direct or indirect sperm transfer; when indirect, the male emits a spermatophore on the ground and then inserts it with his chelicerae in the female’s genital pore. To do this, he flings the female on its back. The female then digs a burrow, into which it lays 50 to 200 eggs, depending on the species. These are guarded until they hatch. Because the female will not feed during this time, it will try to fatten itself beforehand, and a species of 5 cm has been observed to eat more than 100 flies during that time in the laboratory.^[1]

Like Pseudoscorpions and harvestmen, they lack book lungs. In some species there are very large central eyes that are capable of recognizing forms, which are used for hunting. Lateral eyes are only rudimentary or lacking. Males are usually smaller than females, with longer legs.^[1]

As indicated by their name, Solifugae are mostly nocturnal, and seek shade during the day. It was this behaviour which led coalition soldiers in the 2003 invasion of Iraq to think these arachnids were attacking them. In reality, they were merely moving toward the newly available shade provided by the soldiers’ presence. The absence of shade sends them away.

Urban legends

Solifugae are the subject of many urban legends and exaggerations about their size, speed, behavior, appetite, and lethality. They are not especially large, the biggest having a leg span of perhaps 12 centimeters (5 in). They are fast on land compared to other invertebrates, the fastest can run perhaps 16 kilometers per hour (10 mph), nearly half as fast as the fastest human sprinter. Members of this order of Arachnida apparently have no venom, with the possible exception of one species in India (see below) and do not spin webs.

In the Middle East, it is widely rumored among American and coalition military forces stationed there that Solifugae will feed on living human flesh. The story goes that the creature will inject some anaesthetizing venom into the exposed skin of its sleeping victim, then feed voraciously, leaving the victim to awaken with a gaping wound. Solifugae, however, do not produce such an anaesthetic, and they do not attack prey larger than themselves unless threatened. Other stories include tales of them leaping into the air, disemboweling camels, screaming, and running alongside moving humvees; all of these tales are dubious at best. Due to their bizarre appearance many people are startled or even afraid of them. The greatest threat they pose to humans, however, is their bite in self-defense when one tries to handle them. There is essentially no chance of death directly caused by the bite, but, due to the strong muscles of their chelicerae, they can produce a proportionately large, ragged wound that is prone to infection.

Venom controversy

While the absence of venom in Solifugae is a long-established fact, there is a single published study of one species, Rhagodes nigrocinctus, carried out in India in 1978 by a pair of researchers who did histological preparations of the chelicerae, and found what they believed to be epidermal glands (Aruchami & Sandara Rajulu 1978). Extracts from these glands were then injected into lizards, where it induced paralysis in 7 of 10 tests. While this study has never been confirmed, and while other researchers have been unable to locate similar glands in other species, this particular species does appear to possess venom, although it is not known if there is any mechanism for introducing it into prey (recall that the researchers manually injected it into lizards).

Classification

There are twelve families belonging to the order Solifugae:

• Ammotrechidae
• Ceromidae
• Daesiidae
• Eremobatidae
• Galeodidae
• Gylippidae
• Hexisopodidae
• Karschiidae
• Melanoblossidae
• Mummuciidae
• Rhagodidae
• Solpugidae

The family Protosolpugidae is only known from one fossil species from the Pennsylvanian

Solifugae is an order of Arachnida, containing more than 1,000 described species in about 140 genera. The name derives from Latin, and means those that flee from the sun. The order is also known by the names Solpugida, Solpugides, Solpugae, Galeodea and Mycetophorae. Their common names include camel spider, wind scorpion, sun scorpion and sun spider.

Solifugae are not true spiders, which are from a different order, Araneae. Like scorpions and harvestmen, they belong to a distinct arachnid order.

A Solifugid

Most Solifugae inhabit warm and arid habitats, including virtually all deserts in both the Eastern and Western Hemispheres, excluding Australia^[1]. Some species have been known to live in grassland or forest habitats. The most distinctive feature of Solifugae is their large chelicerae. Each of the two chelicerae are composed of two articles forming a powerful pincer; each article bears a variable number of teeth. Solifugae also have long pedipalps, which function as sense organs similar to insects’ antennae and give the appearance of the two extra legs. Pedipalps terminate in eversible adhesive organs. These are used to capture flying prey, and for climbing. They stridulate with their chelicerae, resulting in a rattling noise^[1].

Solifugae are carnivorous or omnivorous, with most species feeding on termites, darkling beetles, and other small arthropods, although Solifugae have been videotaped consuming larger prey such as lizards. Prey is located with the pedipalps and killed and cut into pieces by the chelicerae. The prey is then liquefied and the liquid ingested through the pharynx. Although they do not normally attack humans, these chelicerae can penetrate human skin, and painful bites have been reported.^[1]

Reproduction can involve direct or indirect sperm transfer; when indirect, the male emits a spermatophore on the ground and then inserts it with his chelicerae in the female’s genital pore. To do this, he flings the female on its back. The female then digs a burrow, into which it lays 50 to 200 eggs, depending on the species. These are guarded until they hatch. Because the female will not feed during this time, it will try to fatten itself beforehand, and a species of 5 cm has been observed to eat more than 100 flies during that time in the laboratory.^[1]

Like Pseudoscorpions and harvestmen, they lack book lungs. In some species there are very large central eyes that are capable of recognizing forms, which are used for hunting. Lateral eyes are only rudimentary or lacking. Males are usually smaller than females, with longer legs.^[1]

As indicated by their name, Solifugae are mostly nocturnal, and seek shade during the day. It was this behaviour which led coalition soldiers in the 2003 invasion of Iraq to think these arachnids were attacking them. In reality, they were merely moving toward the newly available shade provided by the soldiers’ presence. The absence of shade sends them away.

Urban legends

Solifugae are the subject of many urban legends and exaggerations about their size, speed, behavior, appetite, and lethality. They are not especially large, the biggest having a leg span of perhaps 12 centimeters (5 in). They are fast on land compared to other invertebrates, the fastest can run perhaps 16 kilometers per hour (10 mph), nearly half as fast as the fastest human sprinter. Members of this order of Arachnida apparently have no venom, with the possible exception of one species in India (see below) and do not spin webs.

In the Middle East, it is widely rumored among American and coalition military forces stationed there that Solifugae will feed on living human flesh. The story goes that the creature will inject some anaesthetizing venom into the exposed skin of its sleeping victim, then feed voraciously, leaving the victim to awaken with a gaping wound. Solifugae, however, do not produce such an anaesthetic, and they do not attack prey larger than themselves unless threatened. Other stories include tales of them leaping into the air, disemboweling camels, screaming, and running alongside moving humvees; all of these tales are dubious at best. Due to their bizarre appearance many people are startled or even afraid of them. The greatest threat they pose to humans, however, is their bite in self-defense when one tries to handle them. There is essentially no chance of death directly caused by the bite, but, due to the strong muscles of their chelicerae, they can produce a proportionately large, ragged wound that is prone to infection.

Venom controversy

While the absence of venom in Solifugae is a long-established fact, there is a single published study of one species, Rhagodes nigrocinctus, carried out in India in 1978 by a pair of researchers who did histological preparations of the chelicerae, and found what they believed to be epidermal glands (Aruchami & Sandara Rajulu 1978). Extracts from these glands were then injected into lizards, where it induced paralysis in 7 of 10 tests. While this study has never been confirmed, and while other researchers have been unable to locate similar glands in other species, this particular species does appear to possess venom, although it is not known if there is any mechanism for introducing it into prey (recall that the researchers manually injected it into lizards).

Classification

There are twelve families belonging to the order Solifugae:

• Ammotrechidae
• Ceromidae
• Daesiidae
• Eremobatidae
• Galeodidae
• Gylippidae
• Hexisopodidae
• Karschiidae
• Melanoblossidae
• Mummuciidae
• Rhagodidae
• Solpugidae

The family Protosolpugidae is only known from one fossil species from the Pennsylvanian

The brown recluse spider, Loxosceles reclusa, is a well-known member of the family Sicariidae (formerly placed in a family “Loxoscelidae”). It is usually between 6–20 mm (¼ in and ¾ in), but may grow larger. It is brown and sometimes an almost deep yellow color and usually has markings on the dorsal side of its cephalothorax, with a black line coming from it that looks like a violin with the neck of the violin pointing to the rear of the spider, resulting in the nicknames fiddleback spider, brown fiddler or violin spider. Coloring varies from light tan to brown and the violin marking may not be visible.

Contents [hide]
1 Description
2 Habitat
3 Distribution
4 Venomous bite
5 Bite treatment
5.1 Specific treatments
6 Misdiagnoses
7 References
8 External links

[edit] Description
Since the “violin pattern” is not diagnostic, and other spiders may have similar marking (i.e. cellar spiders and pirate spiders), for purposes of identification it is far more important to examine the eyes. Differing from most spiders, which have eight eyes, recluse spiders have six eyes arranged in pairs (dyads) with one median pair and two lateral pairs. Only a few other spiders have 3 pairs of eyes arranged this way (e.g., scytodids), and recluses can be distinguished from these as recluse abdomens have no coloration pattern nor do their legs, which also lack spines.[1]

[edit] Habitat
Recluse spiders build irregular webs that frequently include a shelter consisting of disorderly threads. These spiders frequently build their webs in woodpiles and sheds, closets, garages, cellars and other places that are dry and generally undisturbed. They seem to favor cardboard when dwelling in human residences, possibly because it mimics the rotting tree bark which they naturally inhabit. They also go in shoes, inside dressers, in bed sheets of infrequently used beds, in stacks of clothes, behind baseboards, behind pictures and near furnaces. The common source of human-recluse contact is during the cleaning of these spaces, when their isolated spaces suddenly are disturbed and the spider feels threatened. Unlike most web weavers, they leave these webs at night to hunt. Males will move around more when hunting while females don’t usually stray far from their web.

[edit] Distribution
The brown recluse spider is native to the United States from the southern Midwest south to the Gulf of Mexico.[2] The native range lies roughly south of a line from southeastern Nebraska through southern Iowa, Illinois, and Indiana to southwestern Ohio. In the southern states, it is native from central Texas to western Georgia. They are generally not found west of the Rocky Mountains.[3] A related species, the brown violin spider (Loxosceles rufescens), is found in Hawaii.[4] Despite many rumors to the contrary, the brown recluse spider has not established itself in California,[5] nor Canada[6]. There are other species of Loxosceles native to the southwestern part of the United States, including California, that may resemble the brown recluse, but these species have never been documented as medically significant.

[edit] Venomous bite

Brown recluse compared to the size of a US pennyAs indicated by its name, this spider is not aggressive and usually bites only when pressed against the skin, such as when tangled up within clothes, bath towels, or in bedding.[7] In fact, many wounds that are necrotic and diagnosed as brown recluse bites can actually be Methicillin-resistant Staphylococcus aureus (MRSA).[7] Actual brown recluse bites are rare. Brown recluse bites may produce a range of symptoms known as loxoscelism. There are two types of loxoscelism: cutaneous (skin) and systemic (viscerocutaneous).

Most bites are minor with no necrosis. However, a small number of bites produce severe dermonecrotic lesions, and, sometimes, severe systemic symptoms, including organ damage. Rarely, the bite may also produce a systemic condition with occasional fatalities. Most fatalities are in children under 7 [8] or those with a weaker than normal immune system. (For a comparison of the toxicity of several kinds of spider bites, see the list of spiders having medically significant venom.)

A minority of brown recluse spider bites form a necrotizing ulcer that destroys soft tissue and may take months to heal, leaving deep scars. The damaged tissue will become gangrenous and eventually slough away. The initial bite frequently cannot be felt and there may be no pain, but over time the wound may grow to as large as 10 inches (25 cm) in extreme cases. Bites usually become painful and itchy within 2 to 8 hours; pain and other local effects worsen 12 to 36 hours after the bite with the necrosis developing over the next few days.[9]

Serious systemic effects may occur before this time, as the venom spreads throughout the body in minutes. Mild symptoms include nausea, vomiting, fever, rashes, and muscle and joint pain. Rarely more severe symptoms occur including hemolysis, thrombocytopenia, and disseminated intravascular coagulation.[10] Debilitated patients, the elderly, and children may be more susceptible to systemic loxoscelism. Deaths have been reported for both the brown recluse and the related South American species L. laeta[11] and L. intermedia.[citation needed] Other recluse species such as the desert recluse (found in the desert southwestern United States) are reported to have caused necrotic bite wounds, though only rarely[6].

Numerous other spiders have been associated with necrotic bites in the medical literature. A partial list includes the hobo spider and the yellow sac spiders. However, the bites from these spiders are not known to produce the severe symptoms that often follow from a recluse spider bite, and the level of danger posed by each has been called into question.[12][13] So far, no known necrotoxins have been isolated from the venom of any of these spiders, and some arachnologists have disputed the accuracy of many spider identifications carried out by bite victims, family members, medical responders, and other non-experts in arachnology. There have been several studies questioning danger posed by some of these spiders. In these studies, scientists examined case studies of bites in which the spider in question was positively identified by an expert, and found that the incidence of necrotic injury diminished significantly when “questionable” identifications were excluded from the sample set.[14][15]

[edit] Bite treatment
First aid involves the application of an ice pack to control inflammation, the application of aloe vera to soothe and help control the pain, and prompt medical care. If it can be easily captured, the spider should be brought with the patient in a clear, tightly closed container so it may be identified. However, by the time the bite is noticed any spider found nearby is not likely to be the culprit.

There is no established treatment for necrosis. Routine treatment should include elevation and immobilization of the affected limb, application of ice, local wound care, and tetanus prophylaxis. Many other therapies have been used with varying degrees of success including hyperbaric oxygen, dapsone, antihistamines (e.g., cyproheptadine), antibiotics, dextran, glucocorticoids, vasodilators, heparin, nitroglycerin, electric shock, curettage, surgical excision, and antivenom.[16][17] None of these treatments have been subjected to controlled, randomized trials to conclusively show benefit. In almost all cases, bites are self-limited and typically heal without any medical intervention.[3]

It is important to seek medical treatment if a brown recluse bite is suspected, as in the rare cases of necrosis the effects can quickly spread, particularly when the venom reaches a blood vessel. Cases of brown recluse venom traveling along a limb through a vein or artery are rare, but the resulting mortification of the tissue can affect an area as large as several inches, to the extreme of requiring excising of the wound. While it is possible, and even likely, that many cases of “brown recluse bites” are indeed misidentifications of other infections or envenomations, the brown recluse has justly earned its reputation.

[edit] Specific treatments
Dapsone is commonly used in the USA and Brazil for the treatment of necrosis. There have been conflicting reports about its efficacy and some have suggested it should no longer be used routinely, if at all.[18]

Wound infection is rare. Antibiotics are not recommended unless there is a credible diagnosis of infection.[19]

Studies have shown surgical intervention is ineffective and may worsen outcome. Excision may delay wound healing, cause abscesses, and lead to objectional scarring.[20]

Anecdotal evidence suggests benefit can be gained with the application of nitroglycerin patches.[21] The brown recluse venom is a vasoconstrictor, and nitroglycerin causes vasodilation, allowing the venom to be diluted into the bloodstream, and fresh blood to flow to the wound. Theoretically this prevents necrosis, as vasoconstriction may contribute to necrosis. However, one scientific animal study found no benefit in preventing necrosis, with results showing it increased inflammation and it caused symptoms of systemic envenoming. The authors concluded the results of the study did not support the use of topical nitroglycerin in brown recluse envenoming.[22]

Antivenom, available in South America, appears to be the most promising therapy. However, antivenoms are most effective if given early and because of the painless bite patients do not often present until 24 or more hours after the event, possibly limiting the effect of this intervention.[23]

[edit] Misdiagnoses
It is estimated that 80% of reported brown recluse bites may be misdiagnosed. The misdiagnosis of a wound as a brown recluse bite could delay proper treatment of serious diseases.[3] There is now a ELISA-based test for brown recluse venom that can determine if a wound is a brown recluse bite, although it is not commercially available and not in routine use.[24][3]

There are numerous documented infectious and noninfectious conditions (including pyoderma gangrenosum, bacterial infections by Staphylococcus and Streptococcus, herpes, diabetic ulcer, fungal infections, chemical burns, toxicodendron dermatitis, squamous cell carcinoma, localized vasculitis, syphilis, toxic epidermal necrolysis, sporotrichosis, and Lyme disease) that produce wounds that have been initially misdiagnosed as recluse bites by medical professionals; many of these conditions are far more common and more likely to be the source of mysterious necrotic wounds, even in areas where recluses actually occur.[3]

Reported cases of bites occur primarily in Arkansas, Texas, Kansas, Missouri, Colorado, and Oklahoma. There have been many reports of brown recluse bites in California (and elsewhere outside the range of the brown recluse); however the brown recluse is not found in California[25] (though a few related species may be found there, none of which has been shown to bite humans). To date, the reports of bites from areas outside of the spider’s native range have been either unverified, or - if verified - specimens moved by travelers or commerce. Gertsch and Ennik (1983) report that occasional spiders have been intercepted in various locations where they have no known established populations; Arizona, California, Colorado, Florida, Maine, Minnesota, New Jersey, Mexico, New York, North Carolina, Wyoming and Tamaulipas (Mexico),[26] which indicates that these spiders may indeed be transported fairly easily, though the lack of established populations well outside the natural range also indicates that such movement does not lead to colonization of new areas. Many arachnologists believe that many bites attributed to the brown recluse in the West Coast are not spider bites at all, or possibly instead the bites of other spider species; for example, the bite of the hobo spider has been reported to produce similar symptoms, and is found in the northwestern United States and southern British Columbia in Canada. However, the toxicity of the hobo spider has been called into question as bites have not been proven to cause necrosis, and the spider is not considered a problem in its native Europe.[27] In addition, published work has shown that tick-induced Lyme disease rashes are often misidentified as brown recluse spider bites.[28]

Species in the genus Latrodectus are commonly known as widow spiders. A number of different species of widow spiders occur in the United States. The black widow spider (L. mactans) and the northern black widow spider (L. variolus) occur in Ohio, although both are relatively uncommon, especially in the northern half of the state. Other species of widow spiders occasionally arrive in shipments of household goods.

The black widow spider has a potent neurotoxic venom and is considered the most venomous spider in North America. However, the female injects such a small dose of venom that it rarely causes death. Reports indicate human mortality at well less than 1% from black widow spider bites.

Identification

The adult female black widow spider has a shiny, jet black, spherical abdomen with two connected red triangles on the underside that form a characteristic hourglass marking. Note, however, that the hourglass color may range from yellowish to various shades of orange or red. Adult females are about 1/2-inch long, not including the legs (about 1-1/2 inches when legs are spread). Adult males are harmless, about half the female’s size, with smaller bodies and longer legs. The male’s abdomen usually has red spots along the upper midline and white lines or bars radiating out to the sides. Newly hatched spiderlings are predominately white or yellowish-white, gradually acquiring more black and varying amounts of red and white with each molt. Juveniles of both sexes resemble the male and are harmless.

Adult female northern black widow spiders are shiny black or brown-black with a row of red spots on the top of the abdomen along the midline. Two reddish triangles resembling a split hourglass are present on the underside of the abdomen.

Life Cycle and Habits

Mating takes place in spring or summer. A common misconception is that the female usually consumes the male after mating. Such behavior rarely occurs. The female lays eggs in a silken sac that is globular shaped and about 1/3 to 1/2-inch diameter. Sacs are white at first, later turning tan or gray. Each sac contains 25 to 250 eggs, and several egg sacs may be produced over the course of a summer. The egg sacs are suspended in the web and guarded by the female. The egg incubation period usually lasts about 4 weeks. The spiderlings hatch and molt (shed their skin) one time while inside the egg sac. They then disperse by ballooning—extruding silk threads and being transported by air currents. Their growth to maturity requires 2 to 4 months depending on the availability of prey. Spiderlings molt several times before reaching maturity.

The black widow spider is a cobweb builder whose silk is very strong. The female constructs a web of crisscrossed silk threads with no recognizable pattern and with a dense area of silk, usually to one side, that serves as the spider’s daytime retreat. At night, the female hangs belly upward in the center of the web. She does not leave her hidden web voluntarily. The web typically is situated near the ground in a dark, sheltered site. Webs often are one foot in diameter.

The web serves to trap the spider’s food, which includes a variety of insects (cockroaches and beetles) and other arthropods. Outdoors, black widow spider webs are usually built in woodpiles, rubble piles, under stones, in hollow stumps, and in rodent burrows. These spiders commonly occur in outbuildings such as privies, sheds, and garages. Indoors, they prefer undisturbed, cluttered areas in basements and crawl spaces.

The northern black widow spider is similar to the black widow except its habitat is marginal land with sparse vegetation. It is found in stumps, hollow logs, and piles of debris, and only rarely indoors.

Bite Symptoms

The severity of an individual’s reaction to the black widow spider bite depends on the area of the body bitten, amount of venom injected, and their sensitivity to the venom. The venom travels in the bloodstream throughout the body and acts on the nervous system, causing varying degrees of pain. Some people report very intense pain. There typically is no necrosis (sloughing) of tissues and no conspicuous swelling.

The bite of a black widow spider initially may go unnoticed, but some people report a short stabbing pain. At first, there may be slight local swelling and two faint red spots, which are puncture points from the fangs. Pain soon begins and usually progresses from the bite site to finally localize in the abdomen and back. Severe cramping or rigidity may occur in the abdominal muscles. Other symptoms may include nausea, profuse perspiration, tremors, labored breathing, restlessness, increased blood pressure, and fever. Symptoms often diminish after a day or so and cease after several days. Serious long-term complications or death are very rare.

First Aid

If bitten, remain calm, and immediately seek medical attention (contact your physician, hospital and/or poison control center). Apply an ice pack directly to the bite area to relieve swelling and pain. Collect the spider (even a mangled specimen has diagnostic value), if possible, for positive identification by a spider expert. A plastic bag, small jar, or pill vial is useful and no preservative is necessary, but rubbing alcohol helps to preserve the spider.

A hospital stay may be recommended, particularly for those with a heart condition or with health problems. A physician may administer a specific antivenin to counteract the venom or calcium gluconate to relieve pain.

Control

Control efforts should target black widow spider webs because that is where the spider spends most of its time. Control is best achieved by following an integrated pest management (IPM) strategy, which involves using multiple approaches such as preventive measures, exclusion, sanitation, and chemical treatment when necessary. IPM requires a thorough inspection of the building to locate the pest. An inspection preferably should be done at night because the black widow spider is nocturnal.

Preventing Spider Bites

In order to prevent spider bites, be sure to wear gloves and a long-sleeved shirt when handling stored cardboard boxes, firewood, lumber, and rocks. Be sure to inspect these clothing items for spiders before putting them on. Shake out clothing and shoes before getting dressed.

Exclusion

Install tight-fitting screens on doors and windows to prevent entry of black widow spiders. Also install door sweeps. Seal or caulk cracks and crevices where spiders can enter the house. Install yellow or sodium vapor light bulbs outdoors since these attract fewer insects for spiders to feed upon.

Sanitation

In order to reduce black widow spider populations, it is very important to eliminate their potential hiding places indoors and outdoors. Black widow spiders are often found in undisturbed, cluttered areas indoors, so discard old boxes, old clothing, lumber, and other unwanted items in basements, crawl spaces, garages, and outbuildings. In such areas, store any items off the floor and away from walls. Remove piles of lumber and rubble outdoors. Remove ivy and other heavy vegetation from the foundation. Do not store firewood against the house. Note that these measures also reduce harborages for the spiders’ prey.

Vacuum thoroughly indoors to remove black widow spiders and their webs and egg sacs. After vacuuming, immediately place the vacuum cleaner bag in a plastic bag, seal tightly, and discard in a container outdoors—this prevents captured spiders from escaping into the home. Wash off the outside of the house using a high-pressure hose, paying particular attention to window wells and other undisturbed areas where webs are built.

Insecticides

There are many labeled pesticides for spider control. Some are labeled for homeowner use, while others are labeled only for the licensed, certified pesticide applicator.

Insecticide treatments should be applied so that the chemical contacts spiders in their webs. A non-repellent insecticidal dust is useful to treat webs because the dust clings to the silk and is likely to be contacted by the spider. Individual exposed spiders can be killed with a non-residual aerosol spray, but any egg sacs will be unaffected.

A wettable powder or microencapsulated formulation of a residual insecticide can be applied to corners, behind and under furniture, behind stored items, etc. to prevent establishment of new spiders.

Residual liquid sprays applied to the outside perimeter of the home are not very effective because of the black widow spider’s web-sitting behavior.

Family Lycosidae

Wolf spiders are found throughout Australia. They are robust, agile hunters that live on the ground in leaf litter or burrows. They are often found in lawns and gardens.

Habitat and Biology

Wolf spiders are found in habitats ranging from dry inland shrublands and woodlands to wet coastal forests and alpine meadows. Some species, such as the Lycosa furcillata and L. godefffroyi are common in suburban gardens. Two of the commonest Australian species are Lycosa godeffroyi and L. leuckartii, with a wide range in the temperate parts of the continent.

Many Wolf Spiders have wide distributions, especially across inland regions. This distribution is aided by their ability to disperse aerially as spiderlings or small juveniles over large distances. Many also have very specific microhabitat preferences such as stream-side gravel beds, montane herb-fields or coastal sand-dunes. Most are wanderers but some build burrows, either open or with a trapdoor, while others may make temporary retreats in vegetation. Arid zone species build turrets to deflect floodwaters during rainy periods, while others use pebbles to plug their burrows. In woodlands, twigs may be used to form a palisade around the top of the burrow. The shape and materials used to form burrows and trapdoors may help to distinguish similar-looking species.

According to the Queensland Museum, two Wolf spider species are known to be predators of cane toads. Lycosa lapidosa will take small toads and frogs while L. obscuroides has been noted biting and killing a large toad within one hour.

Identification

Wolf spider (Dingosa sp). Photo: M Gray © Australian Museum.

Wolf spider with babies and egg sac. Photo: M Gray © Australian Museum.

There are many species of Wolf spider, ranging in size from about 1-8 cm across the legs. Their body colours are typically drab, with most having variegated patterns in brown and yellow, grey, black and white; some inland species are a bright salmon pink below. Often the patterns include radiating lines on the carapace (front of the body) and scroll-like patterns on the abdomen. The spider’s underside is light grey, cream or black, sometimes salmon pink, often with black or white markings superimposed. The sides of their jaws may have a small raised orange spot or ‘boss’. Wolf spiders have eight eyes in three rows (4,2,2), with the four smaller eyes in front and the four largest arranged in a square on top of the high and convex head.

Habits, Mating and Reproduction

Mating takes place outside the female’s burrow at night. Some adult male Wolf spiders of smaller-sized species are known to disperse by air in order to find mates. The male is attracted by scent markings left by the female, often associated with her drag-line silk. Males perform a courtship ritual prior to mating, often involving complex leg and palp signalling to the female.

The female constructs an egg sac of white papery silk, shaped like a ball with an obvious circular seam, which she then carries around attached with strong silk to her spinnerets. When the spiderlings hatch, they are carried around on the female’s back until they are ready to disperse by ballooning or on the ground. Such a high degree of parental care is relatively unusual among spiders.

Wolf spiders live for up to two years.

Toxicity

Symptoms of a Wolf spider bite are usually minor, restricted to local pain or itchiness. Less commonly, symptoms can include swelling, prolonged pain, dizziness, rapid pulse and nausea.

First Aid

Seek medical attention if symptoms persist.

Approximately 3060 years ago David was being pursued by King Saul when he hid in a cave near Jerusalem. A spider made its web across the opening. When Saul saw the web, he called his men away, saying that it was useless to search the cave because the web showed that no one could have entered. So David’s life was saved and he lived on to become King of Israel.

Eight hundred years ago Yoritomo, a warrior from Japanese mythology, was running from his enemies after a defeat in battle when he hid inside a large hollow tree. While he was hiding, a spider built a web across the opening. When his enemies found the hollow tree, they were convinced that Yoritomo was not inside because of the web. Yoritomo escaped to become a shogun (an important military leader).

In 1306, Robert the Bruce and his army had been fighting against King Edward I of England for control of Scotland. Robert was lying exhausted in a barn when he noticed a spider try to fix its web to a beam six times. On its seventh attempt, the spider succeeded. Robert was inspired, saying,

"Now shall this spider teach me what I am to do, for I also have failed six times."

He then gathered together some more followers and they won the next battle. After a successful campaign they eventually defeated Edward’s army in 1319.

Fourteen hundred years ago the prophet Mohammed was being chased by his enemies near Mecca when he hid in a cave. Miraculously, an acacia tree sprang up out of the ground in front of the cave. A wood-pigeon nested in the tree and a spider made its web between the cave entrance and the tree. As a result his enemies overlooked the cave and Mohammed escaped to become the Prophet of Islam

In the Northern Territory, Aboriginal people have depicted spiders in their bark and rock paintings.

Spiders are an important Burnungku clan totem for the Rembarrnga/Kyne people in central Arnhem Land. Spiders in their webs are associated with a sacred rock on the clan estate and the design is connected with a major regional ceremony. These spider totems provide a link with neighbouring clans who also use spider totems in their rituals.

Rock painting of a large huntsman-like spider. Kakadu National Park, Northern Territory. Less than 800 years old. Photo: P Taçon © Australian Museum.

Rock painting of a fish shooting a jet of water at a spider. Kakadu National Park, Northern Territory. Less than 800 years old. Photo: P Taçon © Australian Museum.

Bark painting. Artist: Lena Yarinkura Rembarrnga/Kune language group, Arnhem Land. Purchased by the Australian Museum in 1997 from Maningrida Arts and Culture.

Rock painting of a spider descending next to a woman. Arnhem Land, Northern Territory. Between 500 and 2000 years old. Photo: P Taçon

Tarantulas - the truth behind their evil image

Tarantulas are the movie stars of the spider world. They are cast in films when things hairy, scary and deadly are needed. But despite their appearance and reputation, bites from these spiders usually cause little harm.

So how did they get such a bad reputation?

The Tarantula story starts way back

In 1370, in a small town called Taranto in southern Italy a strange and mysterious epidemic broke out for which the only cure seemed to be wild dancing and music. Occurring every summer for three hundred years, this disease was thought to be caused by the bite of a large, hairy Wolf Spider (Lycosa tarantula), which became known as a Tarantula.

In the 1600s, people discovered that these spiders were virtually harmless. Many then concluded that the whole phenomenon of Tarantism was simply an excuse far a wild party. However, it is now suspected that a spider was involved and the real culprit was a European relative of the Redback or Widow Spider.

As Europeans colonised the world, they saw even bigger and hairier spiders, and called them Tarantulas too. As a result, many large and hairy spiders are now commonly, but incorrectly, called Tarantulas. The only true Tarantulas are the large spiders of the family Theraphosidae. Some examples of spiders from this family include:

• Brazilian Salmon Tarantula (Lasiodora parahybana)
• King Baboon Spider (Citharischius crawshayi)
• Goliath Birdeater Tarantula (Theraphosa blondi)
• Pinktoe Tarantula (Avicularia avicularia)
• Mexican Redknee Tarantula (Euathlus (Brachypelma) smithi)
• Whistling Spider (Selenocosmia crassipes