Latrodectus

A genus of relatively small spiders, the widow spiders, capable of inflicting highly poisonous, neurotoxic, painful bites; they are responsible, along with Loxosceles species (the brown spiders), 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 L. mactans (the black widow spider), are L. bishopi (the red-legged widow spider), L. euracaviensis, L. geometricus, and L. tredecimguttatus. [L. latro, servant, robber, + G. dektes, a biter]

- L. 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.

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Lat·ro·dec·tus -'dek-təs n a genus of nearly cosmopolitan spiders of the family Theridiidae that includes most of the well-known venomous spiders (as the black widow, L. mactans), that are of medium size and dark or black in color and often marked with red, and that have a large globular usu. glossy abdomen and long and wiry legs

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Lat·ro·dec·tus (lat″ro-dekґtəs) [L. latro robber + Gr. daknein to bite] a genus of poisonous spiders. L. macґtans is the black widow spider of the United States; L. bishoґpi is found in southern Florida; L. curarienґsis in Brazil and Argentina; L. geometґricus in California and southern Florida; L. hasselґtii in New Zealand; L. luguґbris is the kara-kurt of Russia; L. maculaґtus is found in South Africa; L. malmigniatґtus in Europe; and L. tredecimguttaґtus in southern Europe and Asiatic Russia.