Brown Widow vs cobweb spiders

Latrodectus geometricus compared with Latrodectus mactans

Taxonomic Classification

Rank	Brown Widow	cobweb spiders
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Arthropoda (artrópode)	Arthropoda (artrópode)
Class same	Arachnida (aracnídeo)	Arachnida (aracnídeo)
Order same	Araneae (aranha)	Araneae (aranha)
Family same	Theridiidae	Theridiidae
Genus same	Latrodectus	Latrodectus
Species	Latrodectus geometricus	Latrodectus mactans

Evolutionary Relationship

Brown Widow and cobweb spiders share a common ancestor at the Genus level: Latrodectus.

Conservation Status

Brown Widow

NE — Not Evaluated

cobweb spiders

NE — Not Evaluated

Physical Characteristics

Attribute	Brown Widow	cobweb spiders
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Brown Widow

Habitat

Typically found in terrestrial habitats from forests to deserts.

Range

Widely distributed across Africa (South Africa), Asia (Japan), Europe (7 countries), North America (United States), and South America (Colombia, Ecuador, Peru).

cobweb spiders

Habitat

Typically found in terrestrial habitats from forests to deserts.

Range

Widely distributed across Asia (Japan), Europe (8 countries), North America (United States), and South America (Ecuador).

Brown Widow

The Brown Widow (Latrodectus geometricus) is a species in the genus Latrodectus. Typically found in terrestrial habitats from forests to deserts. Its geographic range includes widely distributed across africa (south africa), asia (japan), europe (7 countries), north america (united states), and south america (colombia, ecuador, peru).

cobweb spiders

The southern black widow (Latrodectus mactans) is one of North America's most recognizable and medically significant spiders, a member of the genus Latrodectus within the family Theridiidae. Females are glossy black with the iconic red hourglass marking on the underside of the abdomen, and reach approximately 8–15 millimeters in body length; males are smaller, paler, and largely harmless. The species constructs irregular, low-lying cobwebs in dark, sheltered locations including woodpiles, outbuildings, hollow logs, rock piles, and debris, where it waits for prey—primarily insects—to blunder into the sticky tangle. Distribution spans the southeastern United States westward through Texas and northward into more temperate zones, with range overlap with related widow species. The venom of Latrodectus mactans contains alpha-latrotoxin, a potent neurotoxin that triggers massive release of neurotransmitters at synaptic junctions, causing the syndrome of latrodectism: severe muscle cramps, pain, hypertension, and autonomic disturbances. Despite its fearsome reputation, bites are rarely fatal in healthy adults when medical treatment is available. Females are cannibalistic toward males, though this behavior is less consistent in nature than laboratory conditions suggest. The species plays an important ecological role in controlling insect populations in arid and semi-arid habitats. Its conservation status has not been formally evaluated by the IUCN.

Shared Countries

Both species can be found in 10 countries:

🇧🇪 Belgium 🇪🇨 Ecuador 🇫🇷 France 🇯🇵 Japan 🇳🇱 Netherlands 🇳🇴 Norway 🇵🇱 Poland 🇸🇪 Sweden 🇬🇧 United Kingdom 🇺🇸 United States