Southern black widow (Latrodectus mactans)

Short answers

Southern black widow: How big does the enclosure need to be?

20×20×25 cm (tall).

Southern black widow: What temperature does it need?

Daytime 24–28 °C, at night 20–22 °C.

Southern black widow: Does it need UVB lighting?

UVB: No UVB needed (nocturnal).

Southern black widow: How long do they live?

Life expectancy: females ~1–3 years (up to 4 in captivity), males considerably shorter.

Southern black widow: Is it suitable for beginners?

No – better suited to experienced keepers (difficulty: Expert).

Climate

Daytime temperature

24–28 °C

Night temperature

20–22 °C

Basking spot

—

Humidity

40–60 %, well ventilated

UVB

No UVB needed (nocturnal)

Enclosure

Minimum size

20×20×25 cm (tall)

Substrate

A thin layer of slightly damp sphagnum or coco humus; twigs, cork and bark as anchor points for the web

Feeding

Food

Crickets, roaches, flies

Feeding interval

adults ~1×/week, juveniles 2×/week

Key facts

Adult size

females ~8–13 mm body (leg span up to ~38 mm), males about half that size

Life expectancy

females ~1–3 years (up to 4 in captivity), males considerably shorter

Origin

South-eastern North America (USA)

Protection status

Not native, no CITES. A medically significant venomous spider (the classic "black widow", latrodectism) → observe the German states' dangerous-animal law (a ban with grandfathering in North Rhine-Westphalia, a permit requirement in Bavaria).

Brumation

Not essential; in cold regions they become inactive in winter

Cohabitation

Keep them singly. Widows are solitary, opportunistic cannibals: a conspecific is eaten when food is scarce, and spiderlings eat their siblings soon after hatching. That the female eats the male after mating happens less often than commonly claimed, but it is possible. For breeding, put the male in only briefly and under observation and separate them again afterwards.

Notes

A red hourglass mark on a black underside. Bitey when disturbed, and medically serious (antivenom exists). A safety-catch container is essential. A common mistake: conditions that are too damp or poorly ventilated.

Do you keep this species?

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Related species

• Brown widow (Latrodectus geometricus) – Expert
• Mediterranean black widow (Latrodectus tredecimguttatus) – Expert
• Northern black widow (Latrodectus variolus) – Expert
• Red widow (Latrodectus bishopi) – Expert
• Redback spider (Latrodectus hasselti) – Expert
• Pale widow (Latrodectus pallidus) – Expert
• Western black widow (Latrodectus hesperus) – Expert
• Noble false widow (Steatoda nobilis) – Intermediate

All species in the care wiki →

What you need to start

To keep Southern black widow (Latrodectus mactans) you typically need: a suitable enclosure (20×20×25 cm (tall)), substrate (A thin layer of slightly damp sphagnum or coco humus; twigs, cork and bark as anchor points for the web), a heat source with a thermostat, UVB lighting, thermometer and hygrometer, a water dish and hides. You will find equipment in the Reptoria marketplace.