Giant House Spider
Eratigena duellica (syn. Tegenaria duellica / Eratigena atrica species complex)
Agelenidae (Funnel-Weavers), Order Araneae
Physical Description
A medium-to-large spider with an oval-shaped, slightly flattened abdomen and an elongate, pear-shaped cephalothorax. The body is covered in fine hair, giving it a velvety matte appearance. Legs are long and slender compared to the body.
Size Estimate
Body length is approximately 10-18 mm, with a leg span extending up to 50-75 mm (2-3 inches). Based on proportion and leg length, this specimen appears to be an adult.
Coloration & Markings
Dark brown to charcoal and earthy yellow-brown base. The carapace features two darker longitudinal bands with lighter central and lateral stripes. The abdomen typically exhibits a lighter central cardiac mark flanked by dark chevrons or spots.
Web Type
Constructs a flat, sheet-like funnel web made of non-sticky silk, usually anchored in corners, crevices, or behind objects with a tubular retreat where the spider hides.
Eye Arrangement
8 eyes of similar size arranged in two slightly procurved rows of four across the front of the carapace, typical of Agelenidae.
Leg Characteristics
Long, thin, hairy legs without strong contrasting bands, uniform dark brown/tan color with fine setae and small spines present along the segments.
Venom & Safety Information
Venom Information
Contains mild, non-harmful venom designed to immobilize small insect prey. It is not medically significant to humans or domestic pets.
Medical Significance
Harmless to humans. Bites are extremely rare because the spider prefers flight over defense, and its fangs struggle to pierce human skin; symptoms if bitten are usually limited to mild localized redness or minor swelling similar to a bee sting.
Safety Recommendations
No control measures are necessary. If relocating is desired, place a clear container over the spider, slide a stiff piece of paper beneath, and release it outside near a shed, stone wall, or woodpile.
Habitat & Behavior
Habitat & Range
Common across Western and Central Europe, widely introduced and established in the Pacific Northwest of North America. Commonly found in human structures like basements, sheds, barns, garages, and woodpiles.
Behavior & Temperament
Fast-moving, agile hunter that relies on speed rather than sticky webs. Shy, nocturnal, and non-aggressive towards humans, opting to run rapidly to cover when disturbed.
Diet & Prey
Feeds primarily on crawling insects including beetles, ants, cockroaches, flies, and other smaller spiders that walk onto its sheet web or path.
Seasonal Activity
Most noticeable in late summer through autumn (August to October) when mature males leave their webs to actively search indoor spaces for females.
Description
The Giant House Spider (Eratigena duellica) is one of the largest and fastest spider species found in suburban and indoor habitats across Europe and parts of North America. Often feared due to its swift movements and leg span, it is a beneficial predator that helps keep insect populations in check inside buildings and outdoor structures.
Key Features
Distinctive funnel-weaver body shape with elongated legs, dark brown carpeted appearance, dull chevron pattern on abdomen, and high speed across surfaces.
Similar Species
Tegenaria domestica (Barn Funnel Weaver, smaller size), Eratigena agrestis (Hobo Spider, lacks dark spots on sternum and has slightly different abdominal pattern), Lycosidae (Wolf Spiders, different eye arrangement and lack funnel webs).
Life Cycle
Females produce spherical, silk egg sacs often coated with debris for camouflage. Males roam actively in late summer and autumn searching for mates. Lifespan is around 2 to 3 years for females, while males die shortly after mating.
Ecological Importance
Serves as an effective natural pest controller in homes, outbuildings, and gardens, controlling populations of pest insects and smaller arachnids.
Conservation Status
Not evaluated by the IUCN, but populations are extremely common, stable, and thriving alongside human development.
Interesting Facts
Eratigena duellica once held the Guinness World Record for the fastest spider, capable of running over 1.73 feet per second (0.53 m/s) in short bursts.
Photography Tips
Use a flash or strong auxiliary light to highlight the dorsal patterns on the carapace and abdomen. Take top-down shots perpendicular to the wooden background to accurately capture body proportions.
Identified: 2026-07-24T14:40:41.615392