Latrotoxin
Guides
Latrodectus
widow spiders, black widow spiders, brown widow spiders
Latrodectus is a genus of cobweb spiders (Theridiidae) containing approximately 34-35 species distributed worldwide except Antarctica. Females are typically dark-colored with distinctive reddish ventral abdominal markings, often hourglass-shaped, while males and juveniles frequently display dorsal red or red-and-white patterns. The genus is medically significant due to potent venom containing the neurotoxin latrotoxin, which causes the condition latrodectism. Despite their reputation, bites rarely cause death in humans. The common name "widow spiders" derives from observations of sexual cannibalism, though this behavior is more common in laboratory settings than in nature.