Southern Black Widow
Latrodectus mactans
Family Theridiidae (Cobweb Spiders), Order Araneae
Physical Description
Found in this image are numerous spiderlings (babies) recently emerged from an egg sac. The adults are known for their shiny, jet-black globular abdomens. Females are significantly larger than males, which are smaller, brown, and more elongated with white/red streaks.
Size Estimate
Spiderlings: 1-2mm. Adult females: Body length 8-13mm with a leg span up to 25-30mm. Adult males: 3-5mm.
Coloration & Markings
Spiderlings start as orange, tan, or white with dark spots. Adult females are famous for the red hourglass marking on the ventral (underside) side of the abdomen. Adult males often retain juvenile colors with red and white lateral stripes.
Web Type
Tangle web or cobweb. A messy, irregular, three-dimensional structure made of high-tensile strength silk, usually built in dark, undisturbed corners.
Eye Arrangement
Eight eyes arranged in two rows of four. The lateral eyes are widely separated from the median eyes, a characteristic of the Theridiidae family.
Leg Characteristics
Slender, hairless-looking legs. The fourth pair of legs has a row of serrated bristles (comb-foot) used to wrap prey in silk.
Venom & Safety Information
Venom Information
Neurotoxic venom containing alpha-latrotoxin. It affects the nervous system by causing a massive release of neurotransmitters.
Medical Significance
Medically significant. Bites cause latrodectism, characterized by severe muscle pain, abdominal cramps, and sweating. While rarely fatal to healthy adults, medical attention should be sought, especially for children or the elderly.
Safety Recommendations
Wear gloves when moving firewood or cleaning out dark storage areas. If bitten, remain calm, ice the area, and seek medical evaluation. Spiderlings can be safely relocated outdoors using a soft brush.
Habitat & Behavior
Habitat & Range
Common across the Southeastern United States. Preferred habitats include woodpiles, garages, basements, crawlspaces, and hollow stumps.
Behavior & Temperament
Reclusive and non-aggressive. They typically stay in their webs and only bite when pressed against skin or when defending an egg sac.
Diet & Prey
Insects such as beetles, cockroaches, and crickets. They use their strong silk to tangle prey before delivering a paralyzing bite.
Seasonal Activity
Most active during late summer and autumn when females are fully grown and producing egg sacs.
Description
The Southern Black Widow is one of the most iconic spiders in North America. While feared for its potent neurotoxic venom, it is a shy species that plays a vital role in controlling pest populations. This image captures the 'nursery' stage where dozens of spiderlings have just hatched and are exploring their immediate environment before dispersing.
Key Features
Spherical black abdomen (adult female), red hourglass marking (adult female), and messy, strong tangle webs.
Similar Species
Latrodectus variolus (Northern Black Widow), Latrodectus hesperus (Western Black Widow), and Steatoda grossa (False Black Widow, which lacks the red hourglass).
Life Cycle
Females produce several papery, tan pear-shaped egg sacs containing 200-400 eggs. As seen in the photo, spiderlings emerge and often disperse via 'ballooning' on silk threads.
Ecological Importance
Significant natural pest control, feeding on nuisance insects like flies and wood-boring beetles.
Conservation Status
Not listed by IUCN; stable and common throughout its range.
Interesting Facts
Despite the name 'widow,' females do not always eat the males after mating; this behavior is more common in laboratory settings than in the wild. Their silk is one of the strongest natural fibers known.
Photography Tips
To photograph the hourglass, look through the web from below. For spiderlings, use a macro lens to capture the spotting patterns on their tiny abdomens.
Identified: 2026-07-16T22:33:58.346477