a genus of relatively small spiders, the widow spiders, capable of inflicting highly poisonous, neurotoxic, painful bites; they are responsible, along with Loxosceles (the brown spider), for most of the severe reactions from spider envenomation. Medically important species are known from australia, North and south America, south africa, and new zealand. Some venomous species, in addition to latrodectus mactans (the black widow spider), are latrodectus bishopi (the red-legged widow spider), latrodectus euracaviensis, latrodectus geometricus, and latrodectus tredecimguttatus.
Origin: L. Latro, servant, robber, – g. Dektes, a biter
latrodectus mactans, the black widow spider, a venomous jet-black spider found in protected dark places; it is especially common in the southern U.S.; the full grown female (slightly more than 1 cm long) has a brilliant red dumbbell-or hourglass-shaped mark on the ventral aspect of the abdomen, and her bite may be extremely painful, producing a syndrome mimicking an acute abdominal crisis; some deaths, though rare, have been reported, particularly in small children; the male spider lacks the hourglass mark and is not venomous.