Southern Black Widow, Hourglass Spider, Shoe-Button Spider
Latrodectus mactans
Theridiidae (Cobweb Spiders), Order Araneae
Physical Description
The spider has a globular, highly glossy abdomen and a smaller cephalothorax. The body texture is smooth and shiny. Females exhibit pronounced sexual dimorphism, being much larger and darker than males, with a rounded, bulbous abdomen.
Size Estimate
Body length of the adult female is approximately 8 to 13 mm, with a leg span reaching up to 38 mm.
Coloration & Markings
Jet-black base coloration with a distinctive, bright red hourglass-shaped marking on the ventral side of the abdomen. Juveniles and some adult females may show additional red spots or white/yellowish lateral stripes, which usually fade with age.
Web Type
Irregular, three-dimensional cobweb (tangle web) constructed in dark, undisturbed corners, often near ground level or inside protective crevices.
Eye Arrangement
Eight small eyes arranged in two horizontal rows of four, typical of the Theridiidae family, with lateral eyes often touching or closely juxtaposed.
Leg Characteristics
Long, slender, glossy black legs without prominent banding or spines, featuring a comb-like row of serrated bristles on the tarsus of the fourth pair of legs used for flinging silk over prey.
Venom & Safety Information
Venom Information
Contains a potent neurotoxin called alpha-latrotoxin, which affects the nervous system by causing massive neurotransmitter release. While medically significant and painful, fatalities are exceedingly rare with modern medical treatment.
Medical Significance
Medically significant. A bite causes immediate local pain followed by severe muscle cramps, rigidity in the abdomen and back, sweating, nausea, and restlessness. Medical attention should be sought promptly if bitten, though antivenom is reserved for severe cases.
Safety Recommendations
Wear gloves when moving stacked wood or cleaning dark, undisturbed storage areas. If found indoors, relocate the spider safely using a jar and piece of cardboard, or contact professional pest control if it poses a persistent hazard.
Habitat & Behavior
Habitat & Range
Found throughout the southern and western United States, as well as parts of Central and South America. Prefers dark, dry, sheltered microhabitats such as woodpiles, stone walls, outbuildings, crawlspaces, and under outdoor furniture.
Behavior & Temperament
Non-aggressive and timid, typically retreating when disturbed. Bites usually occur only in self-defense when the spider is accidentally trapped, squeezed, or compressed against human skin.
Diet & Prey
Feeds primarily on crawling and flying insects such as flies, mosquitoes, grasshoppers, beetles, and caterpillars, which become entangled in the sticky threads of its web.
Seasonal Activity
Most active during the warm spring and summer months, with mating peaking in late spring. Adults often seek shelter indoors or in protected outdoor structures as cooler autumn weather arrives.
Description
The Southern Black Widow is one of North America's most recognizable and misunderstood spiders. Featuring a glossy black body highlighted by a brilliant red hourglass, this master of the cobweb plays an important role in controlling insect populations. Though reclusive and reluctant to bite, its potent neurotoxin commands respect and caution from homeowners and nature enthusiasts alike.
Key Features
Glossy jet-black coloration, bulbous rounded abdomen, and the bright red hourglass marking on the underside.
Similar Species
False black widows (Steatoda grossa) which lack the red hourglass and have a more oblong abdomen; male black widows and juveniles which may have red or white markings on the dorsal side.
Life Cycle
Females produce multiple papery, pear-shaped silk egg sacs containing hundreds of eggs each over the summer. Spiderlings disperse via ballooning shortly after hatching. Females can live for up to three years.
Ecological Importance
Acts as an effective natural predator of pest insect populations, helping to maintain ecological balance in natural and suburban environments.
Conservation Status
Common and widespread throughout its natural range, with secure population trends and no special conservation status.
Interesting Facts
Female black widows rarely consume their mates despite their notorious reputation; the name 'widow' stems from the post-mating mortality sometimes observed in confined laboratory settings rather than nature.
Photography Tips
Use a macro lens from a safe distance without touching the spider. Shoot from the side or slightly below to clearly capture the diagnostic red hourglass marking while avoiding sudden movements that might startle the spider.
Identified: 2026-10-13T18:08:13.036106