Southern Black Widow, Shoe-button Spider
Latrodectus mactans
Family Theridiidae (Cobweb Spiders), Order Araneae. Characterized by a comb of serrated bristles on the tarsus of the fourth leg.
Physical Description
A medium-sized spider with a smooth, glossy globose abdomen and a relatively small cephalothorax. Highly sexually dimorphic; females possess the iconic large round abdomen, while males are much smaller with elongated bodies.
Size Estimate
Adult female body length: 8–13 mm (0.3–0.5 in). Leg span: up to 25–38 mm (1–1.5 in). This specimen appears to be an adult female guarding an egg sac.
Coloration & Markings
Deep jet-black glossy body. Most famously recognized for a red hourglass marking on the ventral (underside) side of the abdomen. Juveniles and males may have white or red spotting/striping on the dorsal side.
Web Type
Irregular tangle or cobweb. Three-dimensional, messy-looking structure made of exceptionally strong silk, usually built close to the ground in dark, sheltered areas.
Eye Arrangement
Eight eyes arranged in two rows of four. The lateral eyes are widely separated from the median eyes, a diagnostic feature for the genus Latrodectus.
Leg Characteristics
Long, slender legs. The first pair is the longest. The fourth pair of legs features a 'comb' of hairs used to wrap prey in silk.
Venom & Safety Information
Venom Information
Contains potent neurotoxins (alpha-latrotoxin). The venom affects the nervous system by causing a massive release of neurotransmitters.
Medical Significance
Medically significant. Bites cause 'latrodectism,' characterized by localized pain, muscle cramps, abdominal pain, and sweating. While rarely fatal to healthy adults, medical attention should be sought, especially for children or the elderly.
Safety Recommendations
Wear gloves when reaching into woodpiles or dark corners. If a bite occurs, remain calm, elevate the area, and go to an emergency room. Do not attempt to suck out venom.
Habitat & Behavior
Habitat & Range
Primarily found in the Southeastern United States, but ranges into the Northeast and West. They prefer dark, undisturbed locations like woodpiles, sheds, basements, and crawl spaces.
Behavior & Temperament
Generally shy and reclusive. They are nocturnal hunters that stay in their webs. They are not aggressive and usually bite only when pressed against skin or when defending an egg sac.
Diet & Prey
Primarily insects such as beetles, cockroaches, and flies. They use their strong silk to entangle prey, then deliver a paralyzing bite to liquefy internal tissues.
Seasonal Activity
Most active during late summer and autumn when mating occurs and egg sacs are produced. They overwinter in sheltered crevices.
Description
An iconic and formidable arachnid, the Southern Black Widow is a master of the cobweb. Its obsidian-like sheen and stark red markings serve as a warning of its potent chemical defenses, though it prefers to remain out of sight.
Key Features
Glossy black globose abdomen, red hourglass marking on the underside, and irregular, high-strength cobwebs.
Similar Species
Latrodectus variolus (Northern Black Widow), Steatoda grossa (False Black Widow - lacks red marking), and Latrodectus hesperus (Western Black Widow).
Life Cycle
Females produce white to tan, papery, pear-shaped egg sacs containing 200-400 eggs. Lifespan is typically 1-3 years. Contrary to myth, females do not always eat the male after mating.
Ecological Importance
Critical natural pest control. They consume large quantities of nuisance insects including cockroaches, ants, and beetles.
Conservation Status
Not evaluated by IUCN, but considered stable and common throughout its native range.
Interesting Facts
The silk of a black widow is pound-for-pound stronger than steel. The name 'widow' comes from the belief that the female always kills the male, though this is rare in the wild for this specific genus.
Photography Tips
Focus on the underside to capture the hourglass if possible. Use a macro lens with a small aperture (high f-stop) to get the entire round abdomen in focus.
Identified: 2026-06-22T23:00:23.005592