Latrodectus hesperus
(Western Black Widow)

Taxonomic Hierarchy

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

Common Name (AASMore information icon)

Western 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

Ralph Vary Chamberlin & Wilton Ivie, 1935

Pronunciation

laa-tro-DEK-tuhs HESS-per-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 8mm - 16mm 3mm - 7mm
Eye count 8
Primary Colors
Identifying Traits Smooth or shiny appearance, Spherical body, Unique pattern, Patternless, Striped or banded legs, Legs solid color, Especially long legs
Web style Cobweb


Additional Remarks

  • Not the only “widow spider” in North America; there are also four other species of Latrodectus.
  • Immature females and adult males retain colorful markings on their abdomen; it’s typically only adult females that may be all black on their dorsal surface.
  • Underside of spider has a bright red or orange hourglass-shaped marking. It may sometimes be faded or (rarely) absent entirely.
  • Females of this species are overall typically larger than the females of Latrodectus mactans or L. variolus.
  • “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.
  • Egg sacs are tan or white spheres, about 10mm in diameter, usually having around 100-300 eggs inside; but can be as many as 600 in some cases.

Featured Pictures

Picture of Latrodectus hesperus (Western Black Widow) - Female - Ventral Enlarge picture icon
1
Picture of Latrodectus hesperus (Western Black Widow) - Male - Dorsal Enlarge picture icon
2
Picture of Latrodectus hesperus (Western Black Widow) - Female - Dorsal Enlarge picture icon
3
Picture of Latrodectus hesperus (Western Black Widow) - Female - Ventral Enlarge picture icon
4
Picture of Latrodectus hesperus (Western Black Widow) - Female - Lateral Enlarge picture icon
5
Picture of Latrodectus hesperus (Western Black Widow) - Male,Female - Ventral Enlarge picture icon
6
Picture of Latrodectus hesperus (Western Black Widow) - Male - Dorsal Enlarge picture icon
7
Picture of Latrodectus hesperus (Western Black Widow) - Female - Eyes Enlarge picture icon
8
View All Pictures


Similar Species