Latrodectus Mactans - Description

Description

The mature female is around 1.5 in (38 mm) long and 0.25 in (6.4 mm) in diameter. 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. 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.

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.


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