where is the red marking on a black widow
Latrodectus Latrodectus is a genus of spiders in the family Theridiidae, most of which are commonly known as widow spiders. The genus contains 31 recognized species[2] distributed worldwide, including the North American black widows (L. mactans, L. hesperus, and L. variolus), the button spiders of Africa, and the Australian redback spider. 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 (but not always) hourglass-shaped.