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Black Widow (Latrodectus mactans)


Detailing the physical features, habits, territorial reach and other identifying qualities of the Black Widow.


 Updated: 2/8/2018; Authored By Staff Writer; Content ¬©www.InsectIdentification.org



  Black Widow  
Picture of Southern-Black-Widow
Picture of Southern-Black-Widow Picture of Southern-Black-WidowPicture of Southern-Black-WidowPicture of Southern-Black-Widow


Sighting the small red hourglass shape on the belly of the glossy Black Widow calls for immediate caution and a plan of action.





Female Black Widows are famous for their toxic venom. Males lack toxicity and are not really known to bite. Immature females do not yet have the powerful poison stores that adults develop. The bodies of both genders are shiny and hairless. Juveniles start out brown, white and orange, growing more black as they age. Adult females are glossy and completely black with the trademark red 'hourglass' on the bottom of their round abdomen. Though males change in color and pattern as they mature, they are always smaller in size (by half) compared to the female. Females are known to eat the male after mating, earning them the name 'widow'. Females can store the sperm from one mating session and use it to produce subsequent batches of fertilized eggs. Lifespans for females range from one to three years; males may live about two months.

Found frequently in the southern U.S. states, this species is also called the Southern Black Widow. It tends to spin its web in places that may be disturbed or visited by humans, thus increasing the likelihood of an unfortunate encounter between the them. Webs are irregular in shape, but strong, and are built under stones, near openings of rodent holes, and in outbuildings such as sheds, outhouses or barns. The spider is unlikely to leave its web to hide from insect prey. It does not go out of its way to bite humans, but a female guarding her eggs is more inclined to attack and bite a threat rather than escape.

The venom in adult females is highly poisonous to humans and REQUIRES MEDICAL ATTENTION. Some people feel the bite (like a pin-prick), others do not. Pain will eventually begin at the site of the bite, and then it spreads to the stomach and back with cramping in the first 8-12 hours of the bite. Other symptoms also may include sweating, nausea, tremors, restlessness, fever and a headache.

If you suspect you have been bitten by a Black Widow, do not attempt to suck out the venom. Immediately wash the bite area with soap and water. Put ice on the bite site and elevate that body part. The Mayo Clinic recommends tying a tourniquet above the bite if on an appendage to help slow the spread of the venom. Seek medical attention immediately. Though it is rare for humans to die from a Black Widow bite because victims get medical help, early treatment can reduce pain and other symptoms, and hasten recovery. This treatment may include taking antivenin and other medications. Those with heart conditions may need hospitalization. Every human body is different. It is critical to let a medical professional assess the victim and treat this kind of spider bite.
Basic Information
Common Name: Black Widow
Other Name(s): Southern Black Widow
Scientific Name: Latrodectus mactans
Category: Spider


General Identification
Size (Adult; Length): 3mm to 10mm (0.12in to 0.39in)
Colorwheel Graphic
Identifying Colors: white, red, black, orange, brown, yellow, white
Additional Descriptors: shiny, pattern, hourglass, widow, biting, venomous, harmful




Taxonomic Hierarchy
Kingdom: Animalia
Phylum: Arthropoda
Class: Arachnida
Order: Araneae
Family: Theridiidae
Genus: Latrodectus
Species: mactans


Spider Anatomy (Typical)
Graphic showing basic parts of spider anatomy
1
Legs: Spiders have four pairs of legs and these are attached to the cephalothorax.
2
Pedipalps: Small appendages near the mouth used as taste and smell organs.
3
Cephalothorax: Contains eyes, head, mouthparts, and legs.
4
Abdomen: Contains various organs related to digestion, reproduction, and web-making.
5
Spinnerets: Used in the production of spider silk for fashioning webs or catching prey.
NOTE: Unlike insects, spiders have both an endoskeleton (internal) and exoskeleton (external).


Territorial Reach (A-to-Z)
Note: An insect's reach is not limited by lines drawn on a map and therefore species may appear in areas, regions and/or states beyond those listed below as they are driven by environmental factors (such as climate change), available food supplies and mating patterns. Grayed-out selections below indicate that the subject in question has not been reported in that particular territory. U.S. states and Canadian provinces / territories are clickable to their respective bug listings.
Alabama
Alaska
Arizona
Arkansas
California
Colorado
Connecticut
Delware
Florida
Georgia
Hawaii
Idaho
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Mississippi
Missouri
Montana
Nebraska
Nevada
New Hampshire
New Jersey
New Mexico
New York
North Carolina
North Dakota
Ohio
Oklahoma
Oregon
Pennsylvania
Rhode Island
South Carolina
South Dakota
Tennessee
Texas
Utah
Vermont
Virginia
Washington
West Virginia
Wisconsin
Wyoming
Canadian National Flag Graphic
Alberta
British Columbia
Manitoba
New Brunswick
Newfoundland and Labrador
Nova Scotia
Ontario
Prince Edward Island
Quebec
Saskatchewan
Mexican National Flag Graphic
Mexico


Territorial Area Map (Visual Reference Guide)
The map below showcases (in red) the states and territories of North America where the Black Widow may be found (but is not limited to). This sort of data can be useful in seeing concentrations of a particular species over the continent as well as revealing possible migratory patterns over a species' given lifespan. Some species are naturally confined by environment, weather, mating habits, food resources and the like while others see widespread expansion across most, or all, of North America.
Alaska  
Hawaii  
Prince Edward Is.  
State of Alabama graphic
State of Arizona graphic
State of Arkansas graphic
State of California graphic
State of Colorado graphic
State of Delware graphic
State of Florida graphic
State of Georgia graphic
State of Idaho graphic
State of Illinois graphic
State of Indiana graphic
State of Iowa graphic
State of Kansas graphic
State of Kentucky graphic
State of Louisiana graphic
State of Maine graphic
State of Maryland graphic
State of Michigan graphic
State of Minnesota graphic
State of Mississippi graphic
State of Missouri graphic
State of Montana graphic
State of Nebraska graphic
State of Nevada graphic
State of New England graphic
State of New Jersey graphic
State of New Mexico graphic
State of New York graphic
State of North Carolina graphic
State of North Dakota graphic
State of Ohio graphic
State of Oklahoma graphic
State of Oregon graphic
State of Pennsylvania graphic
State of South Carolina graphic
State of South Dakota graphic
State of Tennessee graphic
State of Texas graphic
State of Utah graphic
State of Virginia graphic
State of Washington graphic
State of West Virginia graphic
State of Wisconsin graphic
State of Wyoming graphic
Canadian territory of Alberta graphic
Canadian territory of British Columbia graphic
Canadian territory of Manitoba graphic
Canadian territory of New Brunswick graphic
Canadian territory of Newfoundland and Labrador graphic
Canadian territory of Ontario graphic
Canadian territory of Quebec graphic
Canadian territory of Saskatchewan graphic
Territory map graphic of the country of Mexico
Contiguous United States shape map layer graphic


Images Gallery for the Black Widow
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