Latrodectus is a broadly distributed genus of spiders, most of which are commonly known as widow spiders. A member of the Theridiidae family, this genus contains 31 species, including the North American black widows (L. mactans, L. hesperus, and L. variolus), the button spiders of Africa, and the Australian redback spider (L. hasseltii). Species vary widely in size. In most cases, the females are dark-coloured and readily identifiable by reddish markings on the abdomen, which are often hourglass-shaped.
These small spiders have an unusually potent venom containing the neurotoxin latrotoxin, which causes the condition latrodectism, both named after the genus. Female widow spiders have unusually large venom glands and their bite can be particularly harmful to large vertebrates, including humans. Only the bites of the females are dangerous to humans. Despite their notoriety, Latrodectus bites are rarely fatal or even produce serious complications.
Female widow spiders are typically dark brown or a shiny black in colour when they are full grown, usually exhibiting a red or orange hourglass on the ventralsurface (underside) of the abdomen; some may have a pair of red spots or have no marking at all. The male widow spiders often exhibit various red or red and white markings on the dorsal surface (upper side) of the abdomen, ranging from a single stripe to bars or spots, and juveniles are often similar to the male pattern. Females of a few species are paler brown and some have no bright markings. The bodies of black widow spiders range from 3–10 mm (0.12–0.39 in) in size; some females can measure 13 mm (0.51 in) in their body length. #featured_wildlife #fw_wildmanrouse #animalelite #awesomeearth #bestnatureshots #big_shotz #bns_animals #fifyshades_of_nature #great_captures_nature #hubs_united #instagood #instanaturefriends_ #ip_connect #live_love_wildlife #magic_marvels #natgeo #nature_brilliance #nature_of_our_world #nature_perfection #marvelouz_animals #ourplanetdaily #picturetokeep_nature #shots_of_animals #show_us_nature #splendid_animals #thebest_capture #wildlife_perfection #wildlifeplanet #world_bestanimal