Black Widow Spider

Description:

The mature female is around 1.5 in (38 mm) long and 0.25 in (6.4 mm) in diameter.[5] She is shiny and black in color, with a red marking in the shape of an hourglass on the ventral (under) side of her very rounded abdomen.[6] There is much variation in female size, particularly in egg-carrying (gravid) females. The abdomen of a gravid female can be more than 0.5 in (~1.25 cm) in diameter. Many female widows also have an orange or red patch just above the spinnerets on the top of the abdomen.[7] The male is either black, or closer to the appearance of the juveniles in color, and is much smaller with a body of less than 1/4 inch (< 0.75 cm). Juveniles have a distinctly different appearance to the adults, the abdomen is grayish to black with white stripes running across it and is spotted with yellow and orange.