Southern House Spider
Kukulcania hibernalis
Filistatidae (Crevice Weavers), Order Araneae
Physical Description
A robust spider with a velvety or finely hairy texture. Females are large and soot-black or dark charcoal-grey with a bulbous, oval abdomen and a somewhat flattened cephalothorax. The pedipalps are unusually long, often mistaken for an extra pair of legs. Males are much slimmer, light brown/amber, and resemble brown recluses.
Size Estimate
The specimen pictured appears to be an adult female with a body length of 13-19mm (approx. 0.5-0.75 inches). Total leg span can reach 2 inches or more.
Coloration & Markings
Uniformly dark charcoal, soot-black, or deep mahogany brown. The cephalothorax is often slightly darker than the abdomen. Unlike many other spiders, there are no distinct stripes or spots on the abdomen, though the fine hairs give it a matte, dusty appearance.
Web Type
Crevice web. It builds a non-sticky, messy, radial web consisting of calamistrated (woolly) silk emanating from a central retreat in a crack, hole, or crevice. It does not build orb webs.
Eye Arrangement
A tight cluster of eight eyes located on a small, raised tubercle at the front-center of the cephalothorax. This 'eye mound' is a primary diagnostic feature for the Filistatidae family.
Leg Characteristics
Thick, powerful legs covered in fine, short hairs. The legs are generally uniform in color, matching the body. Females have a shorter leg-to-body ratio compared to the wandering males.
Venom & Safety Information
Venom Information
The venom is not considered medically significant to humans. It is designed to paralyze small insects and lacks the necrotic or neurotoxic proteins found in North America's dangerous spiders.
Medical Significance
Low danger level. A bite may cause minor localized pain, redness, or swelling similar to a bee sting. No special medical treatment is usually required unless there is an allergic reaction.
Safety Recommendations
These spiders are harmless. If their webs are unsightly, they can be removed with a broom. To relocate one, use a cup and paper to gently scoop it up and move it to a tree with loose bark or a rock pile.
Habitat & Behavior
Habitat & Range
Found throughout the Southern United States, from Florida to California, and into Central/South America. They are synanthropic, frequently inhabiting the exterior of stucco buildings (like the one pictured), eaves, shutters, and barns.
Behavior & Temperament
Extremely sedentary and shy. They spend most of their lives tucked inside their crevice retreats, waiting for vibrations from prey. They are non-aggressive and will almost always retreat if disturbed; they only bite if significantly provoked or crushed.
Diet & Prey
Generalist insectivores. They feed on beetles, flies, crickets, and other crawling insects that stumble into the woolly silk of their radial web.
Seasonal Activity
Active year-round in warmer climates, though sightings increase in the summer when males leave their webs to search for mates.
Description
This is the Southern House Spider, a common inhabitant of structures across the American South. The female’s dark, intimidating appearance and long palps often cause alarm, but she is a beneficial and harmless neighbor. These spiders are architectural specialists, using their unique woolly silk to snag insects along walls and crevices.
Key Features
Velvety dark grey/black coloration; long pedipalps; eyes clustered on a small central mound; messy radial silk coming from a crevice.
Similar Species
Males are frequently misidentified as Brown Recluses (Loxosceles reclusa) due to their color and 'violin' mark, but they have longer pedipalps and different eye clusters. Females are sometimes mistaken for Black Widows but lack the shiny texture and red hourglass.
Life Cycle
Females are long-lived, potentially surviving for several years. They produce a soft, white egg sac kept within their retreat. Mating occurs when males wander in late spring/summer. The spiderlings may stay near the mother's web for a period after hatching.
Ecological Importance
Excellent for natural pest control. Because they live for years and maintain their webs in the same spot, they can significantly reduce the local population of household pests and agricultural nuisance insects.
Conservation Status
Not evaluated by IUCN, but populations are stable and widespread due to their success in human-modified environments.
Interesting Facts
The silk produced by this spider is 'cribellate,' meaning it is combed into a Velcro-like texture using a specialized plate (cribellum) and leg hairs (calamistrum), rather than using liquid glue.
Photography Tips
Focus on the head region to capture the central eye cluster. Macro shots of the woolly silk pattern around the crevice entrance can also provide a confirmed ID.
Identified: 2026-07-04T18:15:32.202912