Widow Spiders | Publications and Educational Resources | Virginia Tech Publications and Educational Resources 444-422 Authors as Published Charles Hannum, Jr., Graduate Student, Entomology, Virginia Tech; Dini M. Miller, Associate Professor and Extension Specialist, Entomology, Virginia Tech Figure 1. Northern black widow with egg sac. (Photo courtesy of Minnesota State University, Cooperativie Extension) Class: Arachnida Family: Theridiidae, comb-footed or cob weaver spiders Species United States: Red widow, Latrodectus bishopi; Brown widow, L. geometricus; Western black widow, L. hesperus; Southern black widow, L. mactans, and Northern black widow, L. variolus Size Adult females have a body length (cephalothorax and abdomen combined) of approximately 1/2 inch (~1.25 cm) and a total leg span of approximately 1-1/2 inches (~4 cm) (Figure 2). However, there is much variation in female size, particularly gravid (egg-carrying) females.

The abdomen of a gravid female can be greater than 1/2 inch (~1.25 cm) in diameter. Males are much smaller, often having a body length less than 1/4 inch (< 0.75 cm) and a leg span of approximately 1/2 inch (~1.25 cm). Description Like all spiders, the widow spiders have two main body parts, the cephalothorax and abdomen. The cephalothorax bears the head and legs (Figure 2). The abdomen is much larger than the cephalothorax. The spinnerets, or silk and web making appendages, are attached to the rear end of the abdomen. On widow spiders, the spinnerets look like a cluster of small cones (Figure 6). Figure 2. Generalized widow spider anatomy ‚ view from underneath the spider. The web of widow spiders is not the orderly, geometric web of the orb weavers and many other spiders, but a tangled mass or cobweb. The widow spider typically lives in a small retreat in one portion of the cobweb and detects vibrations from insects that get trapped in the web.

There are five different species of widow spider found in the United States: the red widow (L. bishopi), the brown widow (L. geometricus), the Western widow (L. hesperus), the Southern widow (L. mactans), and the Northern widow (L. variolus). The Western widow is found mainly west of the Mississippi. The red and brown widows are found mainly in Florida, but the brown widow has been found as far west as Texas. In Virginia, the Northern and Southern black widows are the species typically found. Color Adult Females Females of the Western, Southern, and Northern widows look like the classic black widow spider (Figures 1, 3, 4, and 5). The body is shiny black and the underside of the abdomen has orange-red marking(s) on it. The Western and Southern widows usually have the distinctive red hourglass on the underside of the abdomen although it is important to note that the hourglass is sometimes separated into two triangular parts. The Northern widow almost always lacks a complete hourglass and instead has two red bars on the underside of the abdomen and red bars on the top of the abdomen.

Many female widows will also have an orange-red spot immediately above the spinnerets on the top of the abdomen (Figure 5). Figure 3. Cricket trapped by Western black widow. (Photo by Jason Diltz) Figure 4. Western black widow. (Photo by Jason Diltz) Figure 5. Southern black widow. (Photo by Jeff Hahn, University of Minnesota Cooperative Extension) Figure 6. Close up of spinnerettes. (Photo by John Bellini) The Red widow female has a reddish colored cephalothorax and a dark reddish brown to black abdomen (Figure 7). The underside of the abdomen may bear the red hourglass or there may just be a non-distinctive red mark. The top of the abdomen is spotted with orange and yellow. Figure 7. Red widow adult. (Photo by Jason Diltz) The Brown widow female varies in color from light brown to dark grey (Figure 8) and the hourglass on the underside of the abdomen typically is more orange than red (Figure 9). Lighter colored females may have whitish spots along the upper sides of the abdomen, similar to the marking of immature widow spiders. Figure 8. Brown widow adult.

(Photo by John Bellini) Figure 9. Orange hourglass on brown widow. (Photo by John Bellini) It is important to note that there is considerable variability in the coloration of widow spiders. For instance, populations of the Western black widow have been found that don’t have the typical black and red abdomen but instead maintain the juvenile coloration, similar to Figure 10, into adulthood. Figure 10. Western black widow juvenile. (Photo by John Bellini) Adult Males Male widows may be either completely black or maintain some of the immature coloration. They do not possess the hourglass type marking of the larger females. However, males usually have some red marking located on the top or underside of the abdomen. Juvenile Widows The coloration of the juvenile widow spider typically is quite different from the adult. The abdomen is grayish to black with white stripes running across it and spotted with yellow and orange (Figures 11 and 12). Figure 11. Northern black widow juvenile. (Photo by Charles Hannum) Figure 12. Western black widow juvenile.

(Photo by John Bellini) Habitat Widow spiders generally do not infest homes but prefer dark, close quarters outdoors such as woodpiles or crevices under rocks. Indoors they are found in quiet locations such as basements, crawl spaces, and attics typically nesting in narrow gaps between the wall and a stored box or other object. The habit of building their webs between stationary objects and the wall of a structure sometimes allows widow spiders to become a significant pest of warehouses and similar storage facilities. Life Cycle The female widow spider lays her eggs in a spherical or tear-drop shaped silk sac (Figure 1) approximately 1/2 inch (~1.25 cm) in diameter. Each egg sac contains between 200 and 400 eggs (more are possible). A single female can produce between four and nine egg sacs in a single summer. The female guards the egg sac and moves it from one location to another within her web to maintain a consistent temperature and humidity. The widow spiderlings hatch approximately eight to ten days after they are laid. The new spiderlings undergo a single molt within the sac and emerge from the egg sac after two to four weeks.

The young spiders disperse by ballooning on air currents with a strand of silk. It takes seven additional molts for the young spiderlings to reach sexual maturity. Depending upon geographic location and time of year, the young that survive can reach sexual maturity in as little as three to four months but this is dependent upon suitable temperature and humidity and the availability of prey. Typically, there is only one generation of widow spiders per year. The young overwinter as subadults and become sexually mature in the spring. Mating and egg laying begin shortly after sexual maturity in the late spring. Type of Damage Cobwebs are a nuisance but widow spiders do not damage property. However, like any spider, widow spiders may cause fear and nervousness in people who come into contact with them. Health Risks The chief danger from widow spiders lies in their venom. Widow spider venom is one of the few medically significant venoms possessed by a spider in North America. Widow spiders, although not aggressive, do occasionally bite humans. Bites occur most often when someone accidentally presses the spider into his or her flesh by handling something on which the spider has attached its web.

This is where the widow spider’s habit of nesting in woodpiles or in between boxes and crates in garages and warehouses becomes significant. Additionally, adult females guarding egg sacs may also bite if their web is disturbed although they will usually flee. In general, widow spiders are a very timid group of spiders that will only bite when threatened. The bite from the widow spider causes a set of symptoms in the bite victim known collectively as latrodectism. Latrodectism is caused by the neurotoxic venom injected by the widow. The initial bite is often painless and goes unnoticed; at worst it will feel like a pinprick. The toxin then travels through the nervous system. The first significant symptom is a dull, numbing ache in the region of the actual bite. This ache may progress to painful muscle cramps in the large muscle masses of the body, particularly the abdomen. Additional symptoms may include sweating, nausea, a rise in blood pressure, leg cramps, muscle tremors, loss of muscle tone, heartbeat irregularities, and vomiting. Symptoms and pain begin between 15 and 60 minutes after the bite and generally peak within one to three hours.

Symptoms are usually completely dissipated within 12 to 24 hours. In extremely rare cases (< 1%), death may occur. Very young children and elderly adults are the most susceptible to the widow venom and, therefore, the most likely to experience severe symptoms. If you suspect that you or one of your children have been bitten by a widow spider, seek medical attention immediately and, if possible, bring the spider with you to the medical center for positive identification. Widow Spider Control Methods Nonchemical (Prevention) Exclusion: The best way of dealing with widow spiders is to prevent their entry into the building in the first place. Use weather stripping around windows and doors and seal any openings around pipes entering from the exterior of the building. Use expandable foam for sealing around pipes but do not use foam around electrical conduit. Make sure that window screens are intact. Check firewood and other items stored outdoors for cobwebs and spiders before bringing them inside the home. Inspect and shake out shoes and clothing that have been stored in the garage or attic before bringing them inside or putting them on. Eliminate harborages: Keep indoor closets, attics, and basements dry by either increasing ventilation or using a dehumidifier.

Remove clutter and move boxes or other objects off the floor and away from the wall to eliminate possible spider nesting sites. Vacuum in corners and behind furniture frequently. Prevent bites: Wear gloves when handling firewood or other items that have been stored outdoors or in tool sheds. Wear gloves when cleaning or vacuuming close spaces indoors. Removal: If you discover a widow spider in or around your home the safest way to remove it is with a vacuum (hose attachment). With a vacuum you can remove the spider, the web, and egg sacs all in one safe step. Be sure to remove the bag from the vacuum immediately after use and throw it away outdoors. Chemical Widow spiders are typically not affected by general pesticide applications (baseboard sprays) because they avoid the treated areas. Individual widow spiders can be killed by direct application (to the spider itself) with a labeled pesticide but they may not die immediately and you risk an intoxicated spider running around loose in the house. By far, the non-chemical methods of prevention and removal are your best bet. If necessary, silica dusts or microencapsulated pesticide formulations may be used in attics and crawlspaces and on window frames to prevent spider reinfestation.

In rare situations where widow spiders are numerous indoors, you should seek the services of a professional pest control company. Interesting Facts Widow spiders are not the problem they used to be Historically, outhouses were the primary locations where humans would experience the dreaded widow spider bite. Attracted to the dark, warm area with numerous flying insects, the widow spiders would often nest in the gap beneath the toilet seat. This situation proved particularly dangerous for men! Female widows don’t deserve their reputation The name “widow spiders” came from the belief that the female usually killed and ate the male after mating. It is now known, however, that this practice of “husband killing” was an artifact of the conditions under which observations were made. In early behavioral studies, the male widow spiders were kept in small containers with the females and they could not leave after mating. The usual result was that at some point, the female would mistake the male for prey and he would be eaten. Subsequent studies, both in the laboratory and the field, have shown the female eating the male rarely occurs so long as he is able to leave her web after mating.

Interestingly, there is one spider in the same group as the American widow spiders, the Australian redback spider (Latrodectus hasselti), where the female actually begins eating the male as part of the mating ritual. However, this is a unique example among the spiders. Dangerous but not necessarily deadly Although it is true that human deaths have occurred from widow spider bites, it is important to note that modern fatalities from widow bites occur in less than 1 percent of all people bitten. The chances of dying are so low that one researcher compared the chances of dying from a widow spider bite to your chances of being struck by lightning. References Breene, Robert, 1997. Widow Spiders of North America, American Tarantula Society Publications. Drees, B.M. Jackman, J, 1999. Southern Black Widow Spider, Texas A&M University Extension System in association with Texas Cooperative Extension program. Edwards, G.B., 2002. Venomous Spiders: Venomous Spiders in Florida, Florida Department of Agriculture and Consumer Services. Faith M., 1997. The Black Widow, Alabama Cooperative Extension System, Bulletin ANR-1039.

Lacey, Mark. 1997. Spiders, Chapter 19, pp 883-909 in A. Mallis and D. Moreland [ed], Handbook of Pest Control 8th edition, Mallis Handbook & Technical Training Company. Special Thanks Jason Diltz for the generous permission to use his photographs for this publication. Additional photos by Mr. Diltz may be seen on his website at John Bellini for the generous permission to use his photographs for this publication. Ensuring optimal viewing of ePubs on your device iPhone and iPad users: Be sure to turn off full justification and auto-hyphenation. Visit the Settings app on your device and select iBooks in the left rail to change the default selections. Kindle and Nook users: While reading your ePub, you can adjust your margins and font size to change how the text flows by selecting the “Aa” button (Kindle) or “text” (Nook) to access settings. Rights Virginia Cooperative Extension materials are available for public use, reprint, or citation without further permission, provided the use includes credit to the author and to Virginia Cooperative Extension, Virginia Tech, and Virginia State University.

Publisher Issued in furtherance of Cooperative Extension work, Virginia Polytechnic Institute and State University, Virginia State University, and the U.S. Department of Agriculture cooperating. Edwin J. Jones, Director, Virginia Cooperative Extension, Virginia Tech, Blacksburg; M. Ray McKinnie, Administrator, 1890 Extension Program, Virginia State University, Petersburg. Date Black Widow Spider Facts Black Widow Spider Facts By Jessie Szalay, LiveScience Contributor | October 29, 2014 09:12pm ET MORE A western black widow, Latrodectus Hesperus. One of the few species harmful to people in North America, a black widow often features a red hourglass shape on its underside. Credit: © AMNH\R. Mickens Black widow spiders are arachnids that are known for the females' unique appearance and tendency to eat their mates. They are considered the most venomous spiders in North America; however, their bite is rarely fatal to humans. Black widow appearance Male and female black widows look different.

In all cases, "the females are the most distinctive, with shiny black bodies and a red hourglass-shaped marking on the underside of their round abdomen," said Jo-Anne Nina Sewlal , an arachnologist at the University of the West Indies in Trinidad. The hourglass marking can, on occasion, also be orange-yellow. Female black widows are about 1.5 inches long. The males are about half the size of females. Males are lighter in color, with red or pink spots on their backs, according to the North Carolina Cooperative Extension Service at North Carolina State University (NCSU). Where do black widows live? Black widows are found in temperate regions throughout the world, including the United States, southern Europe and Asia, Australia, Africa, and much of South America. In the United States, they exist primarily in the South and West. They may be found in dark, dry shelters such as "barns, garages, basements, outdoor toilets, hollow stumps, rodent holes, trash, brush and dense vegetation, according to NCSU. Black widow food Like many spiders, the black widow spider eats other arachnids and insects that get caught in their webs.

The female spider hangs upside down from her web as she waits for her prey. This pose shows off her bright markings, which, according to a report published by The Society for Integrative and Comparative Biology , are a visible warning to potential predators that she is toxic. The markings, however, do not appear to frighten off prey. That is likely due to differences in how birds and insects perceive color, according to the report's author. Black widows eat flies, mosquitoes, grasshoppers, beetles and caterpillars, according to National Geographic . After the prey is ensnared in the web, the black widow uses its "comb feet" to wrap the prey in silk. Then, the black widow punctures its prey with its fangs and injects digestive enzymes that liquefy the corpse. The spider then sucks up the fluid. Species of black widows The black widow's comb foot is a distinguishing feature. "Black widow spiders belong to the family Theridiidae, commonly referred to as comb-footed spiders," Sewlal said, adding that comb-footed spiders get their name "because they have a series of stiff short hairs on the last segment of their fourth pair of legs that resemble the teeth of a comb.

This is used to drape the silk over the prey when the spider is wrapping it." "There are actually a few species in the genus Latrodectus that are referred to as 'black widow' spiders in the United States of America," said Sewlal. There are also red widows and brown widows. The taxonomy of black widows, according to the Integrated Taxonomic Information System (ITIS), is: Kingdom: Animalia Black Widow Spiders | National Geographic Black Widow Spiders About Black Widow Spiders Black widows are notorious spiders identified by the colored, hourglass-shaped mark on their abdomens. Several species answer to the name, and they are found in temperate regions around the world. Venom This spider's bite is much feared because its venom is reported to be 15 times stronger than a rattlesnake's. In humans, bites produce muscle aches, nausea, and a paralysis of the diaphragm that can make breathing difficult; however, contrary to popular belief, most people who are bitten suffer no serious damage—let alone death. But bites can be fatal—usually to small children, the elderly, or the infirm.

Fortunately, fatalities are fairly rare; the spiders are nonaggressive and bite only in self-defense, such as when someone accidentally sits on them. The animals most at risk from the black widow's bite are insects—and male black widow spiders. Females sometimes kill and eat their counterparts after mating in a macabre behavior that gave the insect its name. Black widows are solitary year-round except during this violent mating ritual. Webs and Feeding These spiders spin large webs in which females suspend a cocoon with hundreds of eggs. Spiderlings disperse soon after they leave their eggs, but the web remains. Black widow spiders also use their webs to ensnare their prey, which consists of flies, mosquitoes, grasshoppers, beetles, and caterpillars. Black widows are comb-footed spiders, which means they have bristles on their hind legs that they use to cover their prey with silk once it has been trapped. To feed, black widows puncture their insect prey with their fangs and administer digestive enzymes to the corpses. By using these enzymes, and their gnashing fangs, the spiders liquefy their prey's bodies and suck up the resulting fluid. © 1996-2017 National Geographic Society.

The Black Widow: A Venomous Type of Spider - PestWorld Black Widow Spiders Everything You Need to Know About This Venomous Species Black widow spiders are the creatures of scary stories told on Halloween night – deadly females that kill and eat the males and who are poisonous to anyone that dares come near. While there are elements of truth to these stories, the habits of black widow spiders aren’t any different than the habits of other species of spiders. However, of the spiders that interact with humans, the black widow’s characteristics coupled with its health risk make it one of the most dangerous spiders that can be found in or around the home. Being aware of where to find these spiders and the risks they pose can help protect you and your family from being bitten. How dangerous are black widows? Black widow spiders are one of a small number of structure-invading spiders that have both fangs big enough to pierce human skin and venom potent enough to cause severe side effects. According to the Centers for Disease Control and Prevention (CDC), the black widow is the most venomous spider in North America. However, bites are very rarely fatal as the amount of venom injected is so small, and very few people have interactions with black widows in which they are bitten.

In the case of a black widow bite, the Food and Drug Administration (FDA) does produce an antivenin that can be used to counteract the effects of the venom, reducing the side effects and possibility of death in bite victims. What do black widows look like? The good thing about black widows is that they have a very unique appearance. They can be recognized by most people and are easily identified by an expert. Their characteristic all black body is very round and there is a red hourglass or split-hourglass shape under their abdomen. Females can be 3/4 of an inch long with legs over one inch long. Males are about half the size of females. Where are you likely to find a black widow spider? Black widows can be found both inside structures and outdoors. They prefer sheltered and protected areas where potential prey has the opportunity to be caught in their webs. Widows are most active during the night when they spend time spinning webs. These webs are very irregular and can be about one foot in diameter. Outside, they are usually found under stones, in woodpiles or around decks. Occasionally they might live on low tree branches or in shrubs.

However, being partial to protected areas makes man-made structures ideal places for black widows to seek shelter. Common places in the home for these spiders to live are in cluttered or seldom-used areas in the garage, basement or a crawl space. How do you prevent a black widow spider infestation? The best techniques for preventing black widow spiders are keeping the home free of clutter and sealing possible entry points. Standard pest-proofing steps such as installing screens and weather stripping are effective at keeping black widows from getting into your home. Removing old boxes and other unwanted items from dark corners will reduce the number of places for the spiders to hide. When cleaning out these areas of the home, be sure to wear a long-sleeved shirt and gloves to avoid bites from a black widow or other spider that may already be hiding there. If a spider web is visible, use caution before putting hands or feet in that area. It is also good practice to shake out clothing and check in shoes that have been stored in a basement or garage before wearing them. How can I recognize a black widow spider bite? A bite from a black widow spider feels like a pinprick. Pain is usually immediate, but bites are not always felt.

If it is not felt, the only evidence will be a slight swelling with two tiny fang marks. According to Dr. Jorge Parada, medical advisor for the National Pest Management Association, symptoms of a bite include fever, increased blood pressure, sweating and nausea. The main component in black widow venom is a neurotoxin, which causes pain at the bite site and then spreads to other areas of the body such as the chest and the abdomen. Severe reactions could result in muscle cramping. For most healthy people, symptoms of a black widow bite will dissipate within a few days. However, young children and the elderly may be susceptible to severe reactions, Parada warns. Are all black widows bad? Most bites from black widow spiders occur when a spider’s hiding place is discovered or a female is protecting her egg sac. Although they are dangerous, these spiders use their bite as a defense. Black widow spiders do not bite humans instinctively. If you suspect an infestation, contact a licensed pest control professional immediately. This is the safest way to get rid of black widow spiders in your home and keep your family safe.

Your New Year's Resolution Homeowners: If you make one New Year's resolution related to home improvement in 2017, make it this one. Pet Poison Helpline | Black Widow Spider Poisoning in Pets Share Black widow spiders (Lactrodectus spp), which are found throughout North American (except for Alaska), are poisonous to dogs and cats. Female black widow spiders typically are 2-2.5 cm in length, are black, shiny, and have an orange or red hourglass mark on their underside. Immature females are brown in color, and the hourglass shape darkens with age. Males are brown and lack the hourglass mark, and are generally considered non-toxic due to the small size of fang/bite. These spiders carry a potent venom which is a neurotoxin (a-latrotoxin). Dogs and cats bitten by black widow spiders may show clinical signs of severe muscle pain, cramping, walking drunk, tremors, paralysis, blood pressure changes, drooling, vomiting, diarrhea, and death. Treatment includes the use of an antivenom, IV fluids, anti-seizure medications, pain medications, and symptomatic supportive care.

If you suspect your dog or cat were bitten by a black widow spider, call your veterinarian or Pet Poison Helpline immediately for life-saving care. Poison type: Envenomations Alternate names: Lactrodectus, spider, a-latrotoxin Pictured: Black Widow Black widow Facts Black widow Facts Black widow Facts Black widow is a type of spider. There are 31 species of black widows that can be found in temperate regions around the world. Black widows live close to the ground. They can be found in the underground tunnels, dense vegetation or in the dark and dry places such as barns, garages and basements. Black widows are widespread and abundant in the wild. These spiders are not on the list of endangered species. Interesting Black widow Facts: Size of black widow depends on the gender. Females can reach 1.5 inches in length and 0.035 ounces of weight. Males are two times smaller. Females have shiny black body and hourglass-shaped, red marking on the belly. Males are lighter in color and have pink or red spots on their backs. Black widow exposes red marking on its belly to inform predators that it is toxic and dangerous.

Body of black widow is composed of cephalothorax and abdomen (two body segments) and four pairs of legs. Last pair is covered with stiff hairs that look like a comb. Black widow is the most poisonous spider in the North America. It produces toxin that is 15 times stronger than the venom of rattlesnake. Black widow attacks humans only when it is threatened. People rarely die after bite, but they experience nausea, abdominal and muscle pain, sweating, hypertension and difficult breathing. These symptoms may last from 8 hours to few days. Luckily, antivenom (which prevents all these negative effects) is available in most hospitals. Black widow is nocturnal creature (active during the night). Black widow produces the strongest silk in the world of spiders. Shape of the web is not very pretty, but it is durable. Web is designed to catch flies, mosquitoes, moths, beetles, caterpillars, grasshoppers and other spiders - major source of food. Black widow silently waits for the prey in the upside-down position. Once the prey is in the web, spider uses comb-like feet to wrap it into the silk. Like all other spiders, black widows do not chew their prey.

They inject digestive fluids into the victim and consume (better say drink) already digested (liquefied) meal. Wasps, praying mantis and birds are natural enemies of black widows. Black widows are solitary creatures, except during the mating season which takes place during the spring. Female lays 200 to 900 eggs in the sac (called cocoon). Eggs hatch after 30 days. Female often kills and eats her partner after mating, hence the name - black widow. Scientists believe that males represent excellent source of proteins required for the successful development of eggs. Hatchlings often feed on each other (phenomenon known as cannibalism). Only few babies survive to the age of 3 months and reach adulthood. Lifespan of black widow depends on the gender. Males live from one to 4 months, females up to 3 years. Related Links: Hey! A Black Widow Spider Bit Me! Hey! A Black Widow Spider Bit Me! KidsHealth > For Kids > Hey! A Black Widow Spider Bit Me! ¡Ay! ¡Me picó una araña viuda negra! What's a Black Widow Spider?

The black widow spider is one of the few venomous spiders found in the United States (venom is a type of poison). It is part of the arachnid family, which includes not just spiders, but ticks , mites, and scorpions , too. Its body is about one-half inch long (smaller than a dime), and it has long legs. The black widow spider is shiny and black with a red-orange or yellow mark in the shape of an hourglass on its stomach. Black widow spiders and their relatives can be found almost anywhere in the Western hemisphere of the world in damp and dark places. Their favorite places are woodpiles, tree stumps, trash piles, storage sheds, fruit and vegetable gardens, in stone walls, and under rocks. If they come inside, they will go to dark places like corners of closets, garages, or behind furniture. They are shy by nature and bite only when trapped, sat on, or accidentally touched. What a Bite Looks and Feels Like A person who gets bitten by a black widow spider might not know it right away, since the bite can sometimes feel like a little pinprick.

After 30 to 40 minutes, though, the area of the bite will swell and hurt a lot, and sometimes a person can get achy all over. Other symptoms can include weakness, nausea, vomiting, sweating, and headache. What You Should Do If you ever think that you've been bitten by a black widow spider, tell an adult immediately. Black widow spider bites rarely kill people, but it's important to get medical attention as soon as you can because they can make you very sick. With an adult's help, wash the bite well with soap and water. Then apply an ice pack to the bite, and try to elevate the area and keep it still to help prevent the spread of venom (poison). If it's possible, have an adult catch and bring the spider to the doctor's office with you. Even though it's usually easy to identify black widows, you'll want to make sure that's the kind of spider that bit you. The spider can be killed first before you bring it with you; just be sure not to squish it so much that no one can tell what it is. What a Doctor Will Do Doctors treat people who have been bitten by black widow spiders with medications to help relax the muscles and reduce pain.

They sometimes give antivenin, a medication that fights the venom in the spider's bite, if someone who has been bitten has underlying medical problems or doesn't get better from the other medications. How to Avoid Getting Bitten The best way to avoid getting bitten by black widow spiders is to be careful in areas where they like to spend time. Don't play around in rock piles or woodpiles. If you are working outside in the yard in big piles of logs or leaves, wear gloves. Be sure to shake out blankets and clothing that have been stored in the attic or the basement, or if they have been in a closet but not used for a long time. If you are cleaning behind furniture, look carefully behind it before reaching around. If you keep your shoes in a mudroom or garage, shake them out before putting them on. Black Widow Spiders - Facts, Identification & Control Black Widow Spiders Latrodectus spp. Appearance Black widows are identified by red hourglass marking on the underside of their abdomens. Black widows are shiny black in color. Most black widow spiders’ bodies are 3 to 10 mm in size. Females are larger than males and can measure 13 mm in body length.

These spiders are members of the genus Latrodectus. Behavior, Diet & Habits Where Are Black Widow Spiders Found? Black widow spiders favor dark, secluded areas such as crevices and woodpiles. Inside the home, black widows typically hide in sheltered, dimly lit locations such as garages, dark corners, basements, closets and cluttered areas. They thrive primarily in temperate zones and are known to be abundant in the American South. Several species of Latrodectus or “widow” spiders are present in North America. The most common are: the southern widow (Latrodectus mactans) found in the American South and Northeast; Latrodectus hesperus found in the west; the brown widow (Latrodectus geometricus) found in the South; and the northern widow (Latrodectus variolus) found in the Northeast. Characteristics An important characteristic of the black widow spider is its comb foot. This row of strong, curved bristles is located upon the hind pair of legs and is used to pitch silk over captured prey. Black widows are shy in nature. They are solitary, socializing only during copulation.

Black widows are nocturnal and spin webs during daytime. They can sometimes be seen hanging upside down in their web, exposing a telltale hourglass abdominal marking. This marking is bright red and signals danger to predators and attackers. Male vs. Female On average, male black widow spiders are smaller than females, reaching only about half their size in length. However, the legs of the male black widow are considerably longer in proportion to the female’s and are marked by orange and brown at the joints. Males may exhibit red and white stripes on the abdomen depending on the species and are more colorful and finely patterned than females. Diet / Prey: What Do Black Widows Eat? Like most spiders, the food source of the black widow spider includes a variety of arthropods, including ants, caterpillars, grasshoppers, beetles, cockroaches and scorpions, among others. Black widows process their food outside of their bodies. After prey is caught in the web, it is injected with digestive enzymes. They consume the prey after it has softened and liquefied. Following feeding, the abdomen of the spider’s body expands as its stomach fills.

Like most spiders, the black widow is capable of living for several months without food. Some specimens have been known to survive almost one year in the absence of prey. Black Widow Webs Black widows spin a large web where the female suspends a cocoon that can contain hundreds of eggs. These spiders also use their webs to capture their prey, which includes insects such as flies, grasshoppers, beetles, etc.Read more about the black widow’s web . Life Cycle / Reproduction Black widow mating occurs in springtime into early summer. In some cases, black widow females consume males after mating, feeding on them as sources of nutrients needed for egg fertilization. Female black widow spiders can produce several egg sacs in summer months. These sacs are tightly woven, silken cups and are protected fiercely by the female until they hatch. Eggs Egg sacs are white, tan or gray in color, have a paper-like texture, and measure 12 to 15 mm in diameter. They may be pear-shaped or globular. Each egg sac contains hundreds of eggs, from which hundreds of spiderlings emerge. However, only a handful of these young survive, as black widows are cannibalistic during the early stages of their lives.

Black widow spider eggs can be found in dark crevices beneath stones and in natural debris such as woodpiles. Barns and other secondary buildings are likely to host these spiders, as well. Black widow spider eggs may also be deposited within neglected materials or animal and rodent nests. Spiderlings (Babies) Surviving spiderlings undergo molting stages known as instars. Many spiderlings overwinter as immatures, and then they mature fully the following spring. Spiderlings are white and orange in color and resemble adult black widow males. Females turn black as they grow older. Black widow spiderlings are cannibalistic and consume other spiderlings from their brood for nutrients. Surviving hatchlings leave the web within a few days, at which point they experience ballooning. During the ballooning process, black widow spiderlings release strands of silk into the air and are carried to new locations. Black widow spiderlings then begin to spin their own webs and capture their own food. Spiderlings find a hiding place to survive in the winter. When warm weather returns, they finish developing into adults. Although the expected lifespan of black widow spiders is one year, some specimens have been known to live up three years. These spiders live longest in captivity.

Signs of a Black Widow Black widows produce messy, irregular webs . Webs usually are located near ground level and under a protected ledge such as under lawn furniture or wood piles. The female with the iconic red hourglass marking also indicates their presence. More Information Locations In North America, black widows are most common in the southern United States. These areas are more suitable for their life cycles and activities. Black widows prefer dry and dark locations and will seek warm dwellings in winter. However, specimens have been found as far north as Canada. Worldwide, widow species can be found on almost every continent. Northern Black Widow As designated by its name, the northern black widow spider (Latrodectus various) is found primarily in the Northeast United States. They may live as far south as Florida, as far north as Canada and as far west as Texas. Species of widow spiders are also occasionally transported in shipments of household goods to states outside of their natural range. Northern black widows are primarily found in marginal land habitats with sparse vegetation, stumps, hollow logs and piles of debris. Northern black widow spiders are rarely found indoors. However, they may enter human dwellings on piles of firewood or other items brought inside.

Most adult female northern black widow spiders are shiny black in color, with rows of red spots atop the abdomen. Crosswise bars that resemble a red hourglass appear on the underside of the abdomen. Southern Black Widow The weather in the American South is extremely conducive to the development of black widow spiders, and several species can be found. A great example is the southern black widow spider (Latrodectus mactans). They are one of the most common black widow species in the Southern United States. Females spin irregular and nonsymmetrical webs. They do not prefer to venture indoors but can be found in garages or basements near openings to the outdoors such as around garage doors. Like the northern black widow, the female southern black widow spider is jet-black in color and is shiny. They also have a red hourglass-shaped mark on the underside which serves to identify it. How the Black Widow Spider Received its Name The black widow spider received its name due to a story about its mating behaviors. Courtship begins when males go out in search of receptive females. Upon approaching a web-spinning female, the male spider will wait for an indication of her willingness: females interested in mating remain still, allowing males to inseminate them.

As the story goes, following insemination, female black widow spiders kill and feed upon their mates. This story led to the black widow’s name. However, it is a misconception that all female black widows kill and consume their mates. Rather, this behavior is typically only observed in captivity. The black widow contributes to the balance of the ecosystem by consuming insects such as flies and mosquitoes. It also controls crop pest populations, feeding on pests that defoliate plants, including locusts, grasshoppers, beetles and caterpillars. Spider Bites: Black Widow vs. Brown Recluse First Aid See the complete gallery of slideshows. Black Widow Spider vs. Brown Recluse Spider In the U.S., most spiders you will find are harmless, but the black widow spider and the brown recluse spider are exceptions. Both types of spiders are more common in the southern U.S. and in warm, dry climates. Within these areas they tend to be found in environments that are undisturbed such as basements, closets, attics, under sinks, or in wood piles. What Types of Dangers Would You Expect From a Black Widow Bite? The bite of a black widow spider is dangerous because it can affect a person’s nervous system.

The spider produces a neurotoxic protein that is extremely potent. Some people may have a minimal reaction, but others may suffer from a severe response. Black Widow Victims May Experience These Symptoms: Symptoms of a black widow spider bite start within an hour after being bitten. Symptoms include severe muscle cramps, abdominal pain, weakness, and tremor. In severe cases symptoms may include nausea, vomiting, faintness, dizziness, chest pain, and respiratory difficulties. What Type of Dangers Would You Expect From a Brown Recluse Spider? Another toxic spider is the brown recluse, whose venom is more potent than that of a rattlesnake, and is toxic to cells and tissues. However, because the bite releases much smaller quantities of poison into its victims, brown recluse bites cause less damage than rattlesnake bites. Brown Recluse Victims May Experience These Symptoms: Brown recluse spider bites may not even be noticed at first as they are often painless. Some people may notice minor stinging such as that felt with a bee sting when bitten by the spider.

Symptoms of a brown recluse spider bite develop within eight hours after being bitten and include severe pain at the bite site, severe itching, nausea, vomiting, fever, and muscle pain. Who Is the Black Widow Spider? The black widow spider gets its name from the erroneous belief that the female spider kills the male after mating. There are five species of black widow spiders in the U.S.; the southern black widow and the northern black widow are the most common. The spider is medium-sized and about half-inch long. Who Is the Southern Black Widow Spider? The southern black widow spider is one of the two commonly found species of black widow spiders found in the U.S. and can be identified by its shiny, black, globular abdomen with the distinctive red hourglass shape on its underside. Who Is the Northern Black Widow Spider? The northern black widow spider doesn't have the hallmark red hourglass shape on its belly, instead it can be identified by a row of red spots (spots may also be yellow or white) down the middle of the upper surface of its abdomen, and two crosswise bars on the undersurface. The spider may be brown or have red legs. Who Is the Brown Recluse Spider? Brown recluse spiders are native to the U.S.

Midwest and Southeast. It is rare to find them outside these areas. There are 13 other species of spider in the same family that may be falsely identified as a brown recluse. Who Are the Non-Brown Recluse Spiders? Spiders in the same family as the brown recluse spider include the desert recluse found in Texas, Arizona, and California, and the Arizona recluse. Bites from these spiders may cause some localized skin disease, but no deaths have been reported from non-brown recluse spiders. Who Is the Brown Recluse Spider? Brown recluse spiders are identified by their characteristic violin pattern on the back of the cephalothorax (the part of the body where the legs attach). The base of the violin appears to be at the head of the spider and the neck of the violin points to the rear. Brown recluse spiders are small with one-inch legs, non-hairy, yellow-tan to dark brown in color, and darker legs. Most spiders have eight eyes, but the brown recluse has just six – it belongs to the genus Loxosceles. This feature is usually too small for people to see with the naked eye. What Are the Habits of a Black Widow?

Black widow spiders are active at night (nocturnal), and they prefer dark areas. They tend to avoid houses where people live, but they may be found in garages or sheds. Only female black widow spiders bite humans, and they only do so if disturbed. What are the Habits of a Brown Recluse Spider? Brown recluse spiders are not aggressive and will only bite if they feel threatened. They prefer dark, warm, dry environments such as attics, closets, basements, barns, and wood piles. Most brown recluse bites occur during the summer. The spider searches for prey at night and rests in the day in its small web, which is usually constructed in corners or crevices. What Does a Black Widow Spider Bite Look Like? A black widow spider bite may appear as double fang marks at the site of the bite. The bite is described as feeling like a pinprick, though there may only be a small localized reaction. Blood pressure or heart rate may rise. The severity of the reaction to the bite depends on the age and overall health of the victim. Children and the elderly are usually more seriously affected. Progression of Black Widow Spider Bite.

Hours after being bitten by the black widow spider, the bite injury will swell. In the case pictured, two days after being bitten the redness and swelling continued past the elbow and down the forearm of the victim. Eight days after the bite, the swelling went down, the bite opened, and the infection was nearly gone. What Does a Brown Recluse Spider Bite Look Like? A brown recluse spider bite may appear slightly red and when you look closely you may see fang marks. In most cases, the bite site will become firm and will heal over the following days to weeks with minimal scarring. In some cases the local reaction will be more severe with redness, blistering, blue discoloration, tissue death, and scarring. Pictured: the bite area swelled to quarter-size within an hour, and within a day continued to swell, turning blue and dark red. Progressed Brown Recluse Spider Bite (Day Three) In severe cases, the reaction to a brown recluse spider bite can lead to death of the skin (necrosis) and subcutaneous fat. Pictured: the same patient as in the previous slide, after three days, with initial stages of skin necrosis.

Progression of Brown Recluse Spider Bite (Day Nine) As the reaction to the brown recluse spider bite progresses, severe necrotic lesions with deep, wide borders can result. Pictured: the same patient in the previous slides, eight days following the bite. The wound remained open the entire time for the spider’s toxins to drain, and the patient needed constant intravenous antibiotics and pain medications. Progression of Brown Recluse Spider Bite (Day 38) Eleven days after the brown recluse spider bite a five-inch wide area of dead tissue was removed, and a skin graft was needed. Pictured: skin graft results 38 days after the bite. Progression of Brown Recluse Spider Bite (10 Months) Pictured: Ten months after the brown recluse bite, the wound is healed, with scarring. When Should I Seek Medical Care For a Black Widow Spider Bite? Seek care immediately following a black widow spider bite at a hospital emergency department. Most doctor’s offices or urgent care centers are not equipped to deal with these types of injuries. Treatment for pain may require narcotic pain relievers and antivenin to counter the effects of the spider venom, which can usually only be found in a hospital setting.

Are There Self-Care Home Treatments For a Black Widow Spider Bite? For minor black widow spider bites, home care treatments are limited. Cold or awarm compresses and hot baths may help ease pain. Over-the-counter pain relievers such as acetaminophen (Tylenol) or ibuprofen (Advil, Motrin) may help for mild bites. Folk remedies do not work. When Should I Seek Medical Care For a Brown Recluse Spider Bite? If you think you have been bitten by a brown recluse spider see a doctor immediately or go to a hospital emergency department. If possible, bring the spider to the doctor’s office so the physician can identify the spider to help make the proper diagnosis. Are There Self-Care Home Treatments For a Brown Recluse Spider Bite? Clean the wound area thoroughly with soap and water first, and then seek medical care. Home care is for relief of symptoms only after you have been treated by a doctor. Apply ice to decrease pain and swelling, and take acetaminophen (Tylenol) for pain. Elevate the area above the heart if possible. Avoid strenuous activity which can spread the spider venom through the skin. Whose Bite Packs a Bigger Sting?

Be cautious of both black widow spiders and brown recluse spiders if bitten. Both can cause painful bites, which can be deadly in some cases. The brown recluse spider bite can cause severe blistering, blue discoloration, and necrotic lesions with scarring. However, the black widow spider bite can cause severe neurological symptoms especially in children or the elderly. Both types of spiders can be dangerous, and you should seek medical attention if bitten by either type of spider. Stay Informed Get the latest health and medical information delivered direct to your inbox! Plus receive a free PDF Health Report when you sign up! Related Reading

Question: A black widow is a type of what?
Answer: Spider