Southern Black Widow, Shoe-button Spider
Latrodectus mactans
Theridiidae (Cobweb Spiders), Order Araneae. Key family characteristics include a rounded, bulbous abdomen, comb-like setae on the hind tarsi used to pull silk from spinnerets, and irregular tangled webs.
Physical Description
Robust body with a glossy, jet-black, globose abdomen and a smaller, slightly elongated cephalothorax. Females are significantly larger than males, displaying a shiny, smooth integument with a characteristic red or orange marking on the underside of the abdomen.
Size Estimate
Female body length is approximately 8 to 13 millimeters with a leg span up to 38 to 50 millimeters. This specimen appears to be an adult female based on the large, glossy rounded abdomen and mature proportions.
Coloration & Markings
Jet black base coloration overall with a high-gloss sheen. Typically features a vivid red, orange, or yellowish hourglass-shaped marking on the ventral side of the abdomen, though some variations may show spots or broken lines.
Web Type
Irregular, messy three-dimensional cobweb constructed in dark, undisturbed areas close to the ground, featuring sticky vertical catching threads connected to a central retreat.
Eye Arrangement
Eight small eyes arranged in two transverse rows of four, typical of the Theridiidae family, with lateral eyes often touching or closely paired.
Leg Characteristics
Long, slender, smooth black legs without prominent spines, featuring specialized comb-like structures on the hind tarsi for manipulating silk.
Venom & Safety Information
Venom Information
Contains a potent neurotoxin called latrotoxin, which affects the nervous system by causing massive release of neurotransmitters. Potent relative to humans, though rarely fatal with prompt medical care.
Medical Significance
Medically significant. A bite can cause immediate local pain followed by severe muscle cramps, abdominal rigidity, sweating, nausea, and tremors. Seek medical attention promptly if bitten; antivenom and muscle relaxants are effective treatments.
Safety Recommendations
Wear gloves when moving firewood or cleaning dark, undisturbed storage areas. If found inside, gently capture the spider using a deep glass container and stiff paper, then relocate it safely outdoors away from high-traffic zones.
Habitat & Behavior
Habitat & Range
Found primarily in the southern and western regions of the United States, as well as parts of warmer American climates. Prefers dark, dry, sheltered microhabitats such as woodpiles, under stones, hollow stumps, outbuildings, and dark corners of garages.
Behavior & Temperament
Non-aggressive, timid, and defensive rather than offensive. They typically retreat to a hideout when disturbed and only bite defensively when trapped, squeezed, or accidentally compressed against human skin.
Diet & Prey
Primarily feeds on crawling insects such as beetles, ants, grasshoppers, flies, and occasionally other spiders that become trapped in the sticky lower snares of the web.
Seasonal Activity
Most active during spring and summer months, with peak mating occurring in late spring. Overwinters as adults or older juveniles in sheltered microhabitats.
Description
The Southern Black Widow is one of North America's most recognizable and misunderstood spiders. Featuring a glossy black body offset by a brilliant red hourglass, this master of the dark, tangled web plays an essential role in controlling insect populations around human habitations.
Key Features
Glossy jet-black body paired with a distinct red or orange hourglass marking on the underside of a large, globose abdomen, combined with an irregular, sticky cobweb.
Similar Species
False black widows (Steatoda grossa) which lack the red hourglass and have a more brownish, leather-textured appearance; male black widows which are smaller, lighter, and harmless.
Life Cycle
Females produce pear-shaped silk egg sacs containing hundreds of eggs. Spiderlings disperse via ballooning after hatching. Mature females can live up to three years, undergoing multiple molts.
Ecological Importance
Serves as an important predator of pest insects in natural and domestic environments, helping to regulate insect populations while acting as prey for specialized wasps and small birds.
Conservation Status
Widespread, abundant, and secure. Not currently evaluated by the IUCN, with robust populations throughout its native range.
Interesting Facts
Despite their fearsome reputation, black widows rarely bite unless directly threatened. Females occasionally consume males after mating, a behavior from which they derive their common name.
Photography Tips
Photograph from a safe distance using macro lenses or zoom capabilities. Ensure good indirect lighting to capture the glossy black texture and ventral markings without provoking the spider.
Identified: 2026-09-26T16:27:36.071857