Latrodectus

Latrodectus is a genus of cobweb-weaving spiders in the family Theridiidae, commonly called widow spiders. Many species have potent venom and distinctive markings, though appearance varies across the genus.

Theridiidae: Theridiidae is a spider family whose members often build irregular three-dimensional webs. Latrodectus belongs to this family of cobweb-weaving spiders.
Latrotoxin: Latrotoxin is a potent neurotoxin in widow spider venom that triggers neurotransmitter release. It is the principal toxin associated with the severe effects of Latrodectus bites.
Latrodectism: Latrodectism is the syndrome of pain and systemic symptoms caused by a widow spider bite. It names the illness associated with bites from medically significant Latrodectus species.
Southern black widow: The southern black widow, Latrodectus mactans, is a widow spider native to the southeastern United States. This well-known North American species typifies the black widow name.
Steatoda: Steatoda is a genus of cobweb spiders in Theridiidae, often called false widow spiders. Its species resemble widow spiders but belong to a different genus and generally pose less medical risk.
Spider silk: Spider silk is a protein fiber produced by spiders for webs, egg sacs, prey capture, and other functions. Latrodectus uses silk to build webs and protective egg sacs.
Neurotransmitter: A neurotransmitter is a chemical messenger released by neurons to communicate with other cells. Latrotoxin disrupts signaling by provoking excessive neurotransmitter release.
Antivenom: Antivenom is a preparation of antibodies or antibody fragments used to neutralize venom in the body. Antivenom can be considered for severe Latrodectus envenomation.
Western black widow: The western black widow, Latrodectus hesperus, is a widow spider found across western North America. It is a distinct regional species often encountered in medical accounts of widow spiders.
Brown recluse spider: The brown recluse is a venomous spider in the genus Loxosceles, native to parts of the Americas. It is often confused with black widows despite belonging to a different family and causing a different syndrome.

Linked from 3 pages

AraneomorphaeBroader topic: Widow spiders provide a prominent example of venomous araneomorphs.