Black widow spiders are found throughout Tennessee. The most commonly encountered species is the Southern Black Widow, Latrodectus mactans. The Northern Black Widow, Latrodectus variolus, is also present. Both species are widespread across the state.
These spiders typically inhabit dark, undisturbed locations, often found outdoors in woodpiles, under rocks, or in logs. They can also be found in human-made structures such as sheds, garages, and crawl spaces, preferring secluded areas.
Identifying Black Widows
Identifying a black widow spider primarily involves recognizing the adult female. Adult female black widows are typically glossy black with a rounded abdomen. A prominent red or orange hourglass-shaped marking is usually visible on the underside of her abdomen. For the Southern Black Widow (Latrodectus mactans), this hourglass marking is typically connected in the middle.
In contrast, the Northern Black Widow (Latrodectus variolus) female often has an hourglass marking broken into two separate triangles or spots. Females range in body length from approximately 8 to 13 millimeters. They construct irregular, messy webs, often near ground level or in sheltered crevices.
Male black widows are considerably smaller than females, reaching around 3 to 6 millimeters in body length. Their coloration is different, often appearing brown or gray with white stripes and spots on their abdomen. While males may have some red or yellow markings, they typically lack the distinct red hourglass.
Understanding Black Widow Bites and Prevention
A black widow spider bite may initially go unnoticed or feel like a sharp pinprick. Within an hour, localized pain, redness, and swelling may develop around the bite site. Systemic symptoms can follow, including severe muscle cramps or spasms. Other symptoms can include nausea, vomiting, headache, sweating, and weakness.
While black widow bites are rarely fatal, they do require prompt medical attention. Young children and older adults may be more susceptible to severe reactions. Treatment often involves managing symptoms with pain relievers and muscle relaxants; in some severe cases, antivenom may be administered.
To prevent black widow encounters, remove clutter and debris from around homes and in storage areas like basements and garages. Sealing cracks in foundations and ensuring windows and doors have intact screens can help prevent spiders from entering living spaces. When working in areas where black widows might reside, such as gardening or handling firewood, wearing gloves can provide protection. Shaking out shoes or clothing left outdoors before wearing them is also a precaution. If a bite occurs, cleaning the wound with soap and water and applying a cool compress can help reduce pain and swelling while awaiting medical care.