Black widow spiders are found throughout Tennessee. Their venomous bite is a concern for humans. Understanding their characteristics, how to identify them, and their preferred environments can help minimize encounters.
Presence and Identification
Tennessee is home to two primary species of black widow spiders: the Southern Black Widow (Latrodectus mactans) and the Northern Black Widow (Latrodectus variolus). The Southern Black Widow is more common in the state. Adult female black widows have a glossy black body and a distinct red or orange hourglass-shaped marking on the underside of their rounded abdomen.
Female black widows measure around 0.5 to 1.5 inches in length, including their leg span. While the Southern Black Widow has a complete hourglass, the Northern Black Widow’s hourglass marking may appear split or broken into two distinct spots. Male black widows are smaller, often half the size of females, and are brown or gray with less distinct markings, often lacking the prominent red hourglass.
Typical Habitats
Black widow spiders prefer dark, secluded, and undisturbed areas for building their irregular, tangled webs. Outdoors, they are found in woodpiles, under rocks, hollow logs, sheds, barns, outhouses, crawl spaces, under boards, and in dense vegetation.
Indoors, these spiders seek basements, garages, and cluttered storage areas. They enter homes through small cracks or open doors, seeking shelter from extreme weather. Their presence is linked to areas with abundant insect populations, their primary food source.
Understanding the Bite
A black widow spider bite may feel like a pinprick initially, or not be felt at all. Within minutes to an hour, localized pain, redness, and swelling develop at the bite site. The venom, a neurotoxin, affects the nervous system, leading to widespread symptoms.
Symptoms include muscle cramps and spasms that can spread from the bite area to the abdomen, back, or chest, often described as severe pain. Other effects include nausea, vomiting, sweating, headache, fever, and restlessness. While black widow bites are rarely fatal, especially for healthy adults, they can be more serious for vulnerable populations such as young children, the elderly, or those with compromised immune systems. Symptoms improve within two to three days, though milder discomfort can persist for several weeks.
Safety and Management
Minimizing encounters with black widow spiders involves several preventative measures around the home and property. Regularly decluttering storage areas, basements, garages, and outdoor spaces like woodpiles and sheds eliminates potential hiding spots. Sealing cracks and gaps in foundations, walls, and around windows and doors can prevent spiders from entering your home.
When working outdoors where black widows might reside, such as moving firewood or gardening, wearing gloves and long sleeves is important. Shaking out shoes and clothing before putting them on, especially if stored in undisturbed areas, also prevents bites.
If a black widow bite is suspected, immediate medical attention is important. Wash the bite area thoroughly with soap and water, apply an ice pack wrapped in a cloth to reduce pain and swelling, and elevate the affected limb if possible. Do not attempt to extract the venom; instead, contact a doctor or poison control center right away.