Brown Widow Spider, Grey Widow, Brown Button Spider
Latrodectus geometricus
Theridiidae (Cobweb Spiders), Order Araneae. Key family characteristics include a rounded abdomen, comb-like serrated bristles on the tarsus of the fourth leg used to pull silk over prey, and building irregular, tangled three-dimensional webs.
Physical Description
The brown widow features a bulbous, globular abdomen typical of theridiids, a relatively small cephalothorax, and very slender, long legs. Females are significantly larger than males. The body texture is generally smooth and shiny, with prominent, long leg proportions.
Size Estimate
Body length for adult females ranges from 7 to 10 mm with a leg span up to 30 to 38 mm. Males are much smaller, around 2 to 4 mm. This specimen appears to be an adult or subadult female.
Coloration & Markings
Base coloration ranges from tan and grey to dark brown, mottled with black, white, and yellowish geometric patterns dorsally and laterally. As noted, it typically features orange to reddish markings on the dorsal or ventral side, though unlike the black widow's hourglass, the brown widow often has an orange-yellow or red hourglass-shaped marking on the ventral side and geometric spots on the back.
Web Type
Irregular tangle web (cobweb) built in dark, protected, undisturbed areas close to the ground or structural corners like eaves, under furniture, or in vegetation. The silk is notably strong and sticky.
Eye Arrangement
Eight small eyes arranged in two slightly curved, parallel rows of four. The lateral eyes are typically touching or very close, while the median eyes are spaced apart, a diagnostic trait for the Theridiidae family.
Leg Characteristics
Legs are long, thin, and yellowish-brown with distinct dark brown or black bands at the joints. They lack heavy spination but possess a comb-like row of serrated bristles on the fourth tarsi used for wrapping prey.
Venom & Safety Information
Venom Information
Contains neurotoxic components (latrotoxins). However, brown widow venom is generally considered less potent than that of the black widow (Latrodectus mactans), and they typically inject less venom during a defensive bite.
Medical Significance
Medically significant, but much less dangerous than black widows. A bite causes immediate pain, localized redness, and sometimes muscle cramping at the site, but systemic symptoms are rare and typically mild. Seek medical attention if severe pain or spreading symptoms occur.
Safety Recommendations
Wear gloves when clearing out dark, undisturbed areas like garages or patio furniture. If found, safely relocate the spider using a container and a piece of card. If bitten, wash the area with soap and water and apply a cold compress.
Habitat & Behavior
Habitat & Range
Cosmopolitan distribution in tropical and warm temperate regions globally, including parts of the southern United States, South Africa, Australia, and parts of South America. Found around human habitations, outdoor furniture, under ledges, in garages, and vegetation.
Behavior & Temperament
Drawn to dark, sheltered spaces. They are non-aggressive, shy, and retiring spiders that typically flee or play dead when disturbed. Bites usually only occur if pressed directly against human skin.
Diet & Prey
Generalist predators feeding primarily on crawling insects such as ants, beetles, roaches, and other spiders. Prey is caught in the sticky web, wrapped tightly in silk, and subdued with neurotoxic venom.
Seasonal Activity
Active year-round in warmer climates, with peak activity, mating, and web-building occurring during the warm summer and autumn months. They overwinter in sheltered cracks, crevices, and human-made structures.
Description
The brown widow spider is a successful and widespread cosmopolitan species closely related to the infamous black widows. Recognized by its mottled brown and tan patterning, spiky egg sacs, and distinct orange-to-red markings, it frequently chooses to live in close proximity to human structures. Though venomous, it is exceptionally timid and rarely bites unless inadvertently trapped against the body.
Key Features
Tan-to-brown mottled coloration with geometric patterns, spiky/ball-like egg sacs, long banded legs, and an orange or reddish ventral hourglass or dorsal spots.
Similar Species
Latrodectus mactans (Southern Black Widow) and Steatoda nobilis (Noble False Widow). Black widows are glossy black with a distinct red hourglass; false widows lack the comb-like bristles and distinct spiky egg sacs.
Life Cycle
Females produce distinctive spiky or pom-pom-like egg sacs containing 100 to 300 eggs. Spiderlings disperse via ballooning. Females can live for several years in optimal conditions, while males have a much shorter lifespan.
Ecological Importance
Serves as an effective natural predator of common household and garden insect pests, helping to regulate local insect populations while forming a part of the local avian and predatory insect food web.
Conservation Status
Not evaluated by the IUCN, but populations are extremely stable and expanding globally due to human transport and adaptation to urban environments.
Interesting Facts
Brown widow egg sacs are instantly recognizable by the unique silk projections or spikes covering their surface. They are an invasive species in many parts of the world and have in some areas outcompeted native black widow populations.
Photography Tips
Use a macro lens with a flash or external ring light to capture the fine details of the geometric patterns and leg banding. Maintain a safe distance and photograph from the side or slightly above to highlight the abdominal shape and markings without disturbing the spider.
User Notes
Has little red markings on back
Identified: 2026-10-04T02:32:58.396189