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A black western black widow spider with a red hourglass hanging in its web.
Photo: Dllu, CC BY-SA 4.0, via Wikimedia Commons

Western Black Widow

Latrodectus hesperus

A shy, venomous North American spider whose shiny black females have a red hourglass mark on the belly.

🕷️ Arachnids
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About the Western Black Widow

Western black widows live from western Texas, Oklahoma and Kansas north into Canada and west to the Pacific Coast. Females are black with large round abdomens and are about 1.4 inches long; males are much smaller, with longer legs and lighter colors. The red hourglass is on the underside. They spin messy, tangled webs and eat any small creature the web can hold.[1]

Quick facts

Scientific name
Latrodectus hesperus[1]
Size
Females about 1.4 inches (3.5 cm); males about half an inch.[1]
Diet
Carnivore. Any small creature caught in the web.[1]
Habitat
Wooded and dry areas; webs in sheltered spots.[1]
Where it lives
Western North America, from Texas and Kansas north to Canada and west to the Pacific.[1]
Group life
Solitary and nocturnal.[1]
Conservation status
Common; not endangered. Not assessed by the IUCN.[1]

Fun facts

  • Black widows hang upside down in their webs.[1]
  • Only female black widows bite people.[1]
  • Their webs have no neat pattern.[1]

Vocabulary

arachnid
An animal with eight legs and two body parts, such as a spider or scorpion.
venom
A poison an animal injects by biting or stinging.
abdomen
The back part of an insect's or spider's body.
nocturnal
Active mainly at night.
neurotoxin
A poison that affects the nerves.

See it in person

Sources

  1. [1] San Francisco Zoo & Gardens. “Black Widow Spider.” https://www.sfzoo.org/black-widow-spider/ (accessed 2026-10-02)

Facts last checked 2026-10-02.