Western Black Widow

Latrodectus hesperus

True spideradvancedVenom: Medically significant

Medically significant venom

Venom is medically significant. Experienced keepers only — check local legality and have a protocol.

About

A true black widow — keep ONLY with full respect for its MEDICALLY SIGNIFICANT venom (latrodectism). Not a beginner or handleable animal: use a very secure, escape-proof enclosure and never free-handle. Builds a strong irregular cobweb in upper corners; wants warm (70-85°F), fairly dry (40-60%) conditions and appropriately sized prey. Hardy and long-lived for a true spider, and a dramatic display species for experienced, cautious keepers. Know your local regulations and have a plan before keeping.

Taxonomy

FamilyTheridiidae

GenusLatrodectus

Native regionwestern North America

TypeCobweb (terrestrial)

Temperamentshy but defensive; medically significant venom

Size & growth

Adult sizefemale body ~0.3-0.5 in

Length8.00–13.00 mm

Growth ratemedium

Climate

Temperature70–85 °F

Humidity40–60%

Enclosure

Adult sizesecure enclosure with upper corners for a cobweb

Substratedry substrate; anchor points for irregular cobweb

Substrate depth1 inch

Water dishOptional

Feeding

Feeding modePredator (live prey)

Prey sizeappropriately sized crickets / flies

Adult cadence1-2 prey per week

Times kept: 0