Giant House Spider
Eratigena duellica (formerly Tegenaria gigantea)
Agelenidae (Funnel-Weavers), Order Araneae. Characterized by long spinnerets and sheet-like funnel webs.
Physical Description
Large, robust spider with a hairy appearance. The cephalothorax is pear-shaped, and the abdomen is oval and slightly elongated, covered with fine setae (hairs). Visible sexual dimorphism includes males having smaller bodies but significantly longer legs than females.
Size Estimate
Body length 10-18mm; leg span can reach up to 75-100mm (3-4 inches) in adult males. The specimen in the image appears to be a large sub-adult or adult.
Coloration & Markings
Typically mottled shades of brown, beige, and grey. The cephalothorax features two dark longitudinal stripes. The abdomen has a series of 'chevron' markings or spots along the dorsal midline. Legs are usually solid brown without distinct rings or bands in adults.
Web Type
Messy, horizontal sheet web that narrows into a funnel-shaped retreat in a corner or crevice. It is a non-sticky web designed to trip insects and transmit vibrations.
Eye Arrangement
8 eyes of similar size arranged in two nearly straight rows of four. This provides a wide field of view for detecting movement outside the funnel retreat.
Leg Characteristics
Notably long and hairy. The legs lack the prominent spines seen in wolf spiders and do not have the distinct banding found in Eratigena agrestis (Hobo spider).
Venom & Safety Information
Venom Information
Possesses a complex venom mainly designed for paralyzing small arthropods. It is not considered medically significant to humans.
Medical Significance
Harmless. A bite might cause minor localized pain, redness, or swelling similar to a bee sting, but symptoms usually subside quickly. No long-term necrotic effects are associated with this species.
Safety Recommendations
Relocate using the 'cup and paper' method if found indoors and unwanted. To prevent entry, seal cracks in foundations and ensure window screens are intact. No specialized first aid is required for bites beyond cleaning the area.
Habitat & Behavior
Habitat & Range
Native to Europe but widely introduced to North America (especially the Pacific Northwest). Habitats include houses, garages, sheds, and dark crevices in rock walls or tree bark.
Behavior & Temperament
Very fast runner and active hunter. They are generally shy and will retreat into their funnel or a dark corner when disturbed. They are not aggressive toward humans and usually bite only if squeezed or pinned.
Diet & Prey
Generalist predators feeding on flies, beetles, moths, and other spiders. They detect prey by vibrations on their sheet web, then rush out with great speed to subdue it.
Seasonal Activity
Active year-round indoors, but most visible in late summer and autumn when males wander in search of females.
Description
A striking and often misunderstood giant of the household world, the Giant House Spider is a master of speed. Moving at up to 1.7 feet per second, it is one of the fastest spiders for its size. Its presence in a home often indicates a healthy ecosystem where it acts as a top predator among indoor invertebrates.
Key Features
Large leg span relative to body, chevron patterns on abdomen, two dark stripes on cephalothorax, and the lack of distinct leg banding.
Similar Species
Eratigena agrestis (Hobo Spider) which is smaller with banded legs, and Tegenaria domestica (Barn Funnel Weaver) which is much smaller and more distinctly spotted.
Life Cycle
Females produce several globular egg sacs which they guard. Spiderlings emerge and may stay near the web for a short time before dispersing. Lifespan is typically 2-3 years.
Ecological Importance
Highly effective indoor pest control, hunting silverfish, clothes moths, and even other spiders including the Black Widow in some regions.
Conservation Status
Not evaluated by the IUCN; stable and common in human-disturbed habitats.
Interesting Facts
Until recently, they held the Guinness World Record for the fastest spider speed. They are actually known to compete with and displace Hobo spiders, potentially keeping the more 'problematic' species out of homes.
Photography Tips
Avoid using a flash against glass or plastic containers to reduce glare. For ID, focus on the 'top-down' view of the cephalothorax patterns and the dorsal abdomen markings.
Identified: 2026-07-06T19:25:54.840424