Latrodectus is a genus of spider in the big spider family
Theridiidae, most of which are commonly known as
widow spiders. The genus contains 31 recognized
species distributed worldwide, including the North American black widows (
L. mactans,
L. hesperus, and
L. variolus), the
button spiders of Africa, and the Australian
redback. Species vary widely in size. In most cases the females are dark-colored and readily identifiable by reddish hourglass-shaped markings on the abdomen.