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Latrodectus mactans (Fabricius). The southern black widow spider is glossy black and has a complete hourglass marking on the underside of the abdomen. The northern black widow, L. variolus Walchenaer, has the same general appearance but has two red triangles resembling an hourglass, and a row of red spots on top of the abdomen. The southern black widow is usually found outdoors in protected places, such as under rocks and boards and in and around old buildings. The bite of the black widow and other widow spiders usually feels like a pin prick. The initial pain disappears rapidly leaving local swelling and two tiny red marks. Muscular cramps in the shoulder, thigh and back usually begin within 15 minutes to three hours. In severe cases, pain spreads to the abdomen, the blood pressure rises, there is nausea, sweating and difficulty in breathing. Death may result, depending on the victim's physical condition, age and location of bite. Death seldom occurs if a physician is consulted and treatment is prompt.