Giant House Spider
Eratigena duellica (formerly Tegenaria gigantea)
Agelenidae (Funnel-Weavers), Order Araneae. Key characteristics include the construction of flat sheet webs with a funnel-shaped retreat and long, prominent spinnerets.
Physical Description
Large, robust spider with a pear-shaped cephalothorax and an oval-shaped abdomen. The body is covered in fine hairs (setae). They possess powerful chelicerae and long, tapered legs. Females have larger abdomens, while males have smaller bodies and longer legs relative to their size.
Size Estimate
Body length 10–18mm for females; leg span can reach up to 75–100mm (3-4 inches). This appears to be an adult specimen based on the leg-to-body ratio.
Coloration & Markings
Presents a mottled brown, tan, and charcoal grey coloration. The cephalothorax features two broad, dark longitudinal stripes. The abdomen has a central pale 'herringbone' or chevron pattern flanked by darker spots. Legs are typically solid brown without distinct banding.
Web Type
Funnel web. It consists of a horizontal, non-sticky silk sheet that narrows into a silk tube or funnel where the spider hides and waits for prey.
Eye Arrangement
Eight eyes of similar size arranged in two slightly curved rows of four. This arrangement provides a wide field of vision for detecting movement across the sheet web.
Leg Characteristics
Notably long and hairy. They lack the distinct dark banding (rings) often seen in its close relative, the Hobo Spider. The legs are designed for high-speed running across the web surface.
Venom & Safety Information
Venom Information
Possesses a venom that is neurotoxic to its insect prey but has very low potency in humans. It is not considered medically significant.
Medical Significance
Harmless to humans. Bites are rare and usually only occur if the spider is squeezed. Symptoms are typically limited to minor localized pain and redness, similar to a bee sting.
Safety Recommendations
No special precautions needed. If relocation is desired, use the 'cup and paper' method to move the spider outside to a garage or woodpile. Do not handle with bare hands to avoid a defensive nip.
Habitat & Behavior
Habitat & Range
Common throughout Europe and the Pacific Northwestern United States and Canada. Prefers dark, undisturbed areas like basements, crawlspaces, woodpiles, and stone crevices.
Behavior & Temperament
Extremely fast runners (once held the Guinness World Record for spider speed). They are shy and non-aggressive, usually retreating into their funnel at the slightest vibration. They are nocturnal hunters.
Diet & Prey
Generalist predators feeding on various insects, including flies, beetles, moths, and even other spiders. They detect prey via vibrations on the silk sheet before dashing out to subdue it.
Seasonal Activity
Active year-round indoors, but most visible in late summer and autumn (August–October) when males wander in search of mates.
Description
A common sight in cooler climates, the Giant House Spider is an impressive but misunderstood guest. Despite its intimidating size and speed, it is a beneficial predator that monitors the dark corners of homes for pests. Its intricate funnel webs are masterpieces of structural silk.
Key Features
Large size, long hairy legs without bands, two dark stripes on the cephalothorax, and the distinct funnel-web construction.
Similar Species
Hobo Spider (Eratigena agrestis), which is smaller and has different sternum markings; Domestic House Spider (Tegenaria domestica), which is much smaller and has banded legs.
Life Cycle
Females produce several white, papery egg sacs, often incorporating debris for camouflage. Spiderlings disperse via ballooning or crawling. Adults can live for 2–3 years, which is longer than many other temperate spider species.
Ecological Importance
Significant apex predators in the micro-ecosystems of human dwellings and gardens, providing excellent natural pest control of indoor insects.
Conservation Status
Not evaluated by IUCN, but populations are stable and widespread. Often considered an introduced species in North America.
Interesting Facts
At one point, these spiders were recorded running at speeds of 1.7 feet per second. They are known to actively displace the Hobo Spider in homes, likely acting as a natural deterrent against them.
Photography Tips
Focus on the 'top-down' view to capture the abdominal pattern. Use a flash to highlight the fine leg hairs and contrast against the dark funnel retreat.
Identified: 2026-06-27T02:12:12.015060