Latrodectus variolus
(Northern Black Widow)

Taxonomic Hierarchy

  • Kingdom: Animalia
  • Phylum: Arthropoda
  • Class: Arachnida
  • Order: Araneae
  • Suborder: Araneomorphae
  • Family: Theridiidae
  • Genus: Latrodectus
  • Species: Latrodectus variolus

Common Name (AASMore information icon)

Northern Black Widow

Other Common Names

Black Widow, Black Widow Spider, Widow Spider, Hourglass Spider, Shoe Button Spider, Cobweb Spider, Comb-footed Spider, Tangle-web Spider, Gumfoot-web Spider, Button Spider

Author

Charles Athanase Walckenaer, 1837

Pronunciation

laa-tro-DEK-tuhs var-EYE-ol-us

Identification Traits

Disclaimer: The following table provides a quick overview of the spider's basic attributes. The physical traits are greatly generalized in order to aid in the identification and sorting of spider species using our search feature. This information is not exhaustive, and keep in mind that traits such as color, markings, and overall size and shape can vary widely within a species due to variables such as the spider's age, gender, diet, hydration level, climate, and habitat. Though experienced arachnologists and hobbyists can often classify spiders rather accurately based on their unique markings and general appearance, it's important to know that scientifically accurate spider identification relies on detailed taxonomic keys and microscopic examinations of a spider's reproductive organs.

Female iconFemale Male iconMale
Body size More information icon 7mm - 13mm 4mm - 8mm
Eye count 8
Primary Colors
Identifying Traits Smooth or shiny appearance, Spherical body, Unique pattern, Striped or banded legs, Legs solid color, Especially long legs
Web style Cobweb


Additional Remarks

  • In adult females of this species, the red or orange hourglass-shaped marking on the underside of the abdomen is almost always divided (separated into two triangles that do not touch one another). Occasionally, a specimen may only have half of the marking (one triangle) or else none at all. However, males sometimes have a full hourglass marking, or one that is slightly connected in the middle.
  • Adult females typically retain red spots on the top (dorsal) side of their abdomen. Immature females may have red spots plus white lines, similar to the males.
  • This species tends to have larger adult males than Latrodectus mactans or L. hesperus.
  • This species is more common in the northern part of its range (eastern North America), but it still overlaps with Latrodectus mactans, especially in the southeastern states.
  • Egg sacs are white, tan, or grayish spherical or pear-shaped objects hung in the female’s web. They can contain anywhere from 100-400 eggs.
  • “Deadly” is a misnomer! Human deaths are extremely rare from a widow bite (or any other spider bite, for that matter). Anti-venom exists for treatment, but is rarely necessary; pain medication, muscle relaxers, and/or calcium gluconate are often all that’s needed.

Featured Pictures

Picture of Latrodectus variolus (Northern Black Widow) - Female - Ventral Enlarge picture icon
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Picture of Latrodectus variolus (Northern Black Widow) - Female - Dorsal Enlarge picture icon
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Picture of Latrodectus variolus (Northern Black Widow) - Male - Dorsal Enlarge picture icon
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Picture of Latrodectus variolus (Northern Black Widow) - Male - Eyes Enlarge picture icon
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Picture of Latrodectus variolus (Northern Black Widow) - Male - Ventral Enlarge picture icon
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Picture of Latrodectus variolus (Northern Black Widow) - Male - Dorsal Enlarge picture icon
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Picture of Latrodectus variolus (Northern Black Widow) - Female - Lateral Enlarge picture icon
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Picture of Latrodectus variolus (Northern Black Widow) - Female - Dorsal Enlarge picture icon
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