Latrodectus is a broadly distributed genusof spiders with several species that are commonly known as the true widows. This group is composed of those often loosely called black widow spiders, brown widow spiders, and similar spiders.However, the diversity of species is much greater. A member of the family Theridiidae, this genus contains 34 species, which include several North American "black widows" (southern black widow Latrodectus mactans, western black widow Latrodectus hesperus, and northern black widow Latrodectus variolus). Besides these, North America also has the red widow Latrodectus bishopi and the brown widow Latrodectus geometricus, which, in addition to North America, has a much wider geographic distribution. Elsewhere, others include the European black widow (Latrodectus tredecimguttatus), the Australian redback spider (Latrodectus hasseltii) and the closely related New Zealand katipō (Latrodectus katipo), several different species in Southern Africa that can be called button spiders, and the South American black-widow spiders (Latrodectus corallinus and Latrodectus curacaviensis). Species vary widely in size. In most cases, the females are dark-coloured and can be readily identified by reddish markings on the central underside (ventral) abdomen, which are often hourglass-shaped.
| Latrodectus | |
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Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Subphylum: | Chelicerata |
| Class: | Arachnida |
| Order: | Araneae |
| Infraorder: | Araneomorphae |
| Family: | Theridiidae |
| Genus: | Latrodectus Walckenaer, 1805[1] |
| Type species | |
| L. tredecimguttatus (Rossi, 1790)
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| Species | |
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34, see text | |
| Synonyms[1] | |
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