Hobo Spider, Aggressive House Spider
Eratigena agrestis
Agelenidae (Funnel Weavers), Order Araneae
Physical Description
Robust body with a distinct brownish cephalothorax featuring characteristic longitudinal light and dark stripes, and an elongated, oblong abdomen with a chevron pattern. They have a moderately hairy texture and visible spinnerets at the rear of the abdomen.
Size Estimate
Body length ranges from 11 to 18 millimeters for females and 9 to 15 millimeters for males, with a total leg span reaching up to 40 to 50 millimeters.
Coloration & Markings
Dull brown base coloration. The cephalothorax features distinct longitudinal pale stripes. The abdomen shows a noticeable pattern of dark chevron (V-shaped) markings pointing forward, though these can vary in contrast.
Web Type
Builds a characteristic funnel-shaped sheet web out of non-sticky silk. The web typically extends from a secure retreat in a crack, crevice, or corner, terminating in a wide, flat sheet connected to a tubular hiding spot.
Eye Arrangement
Eight small eyes of roughly equal size arranged in two slightly curved, nearly parallel horizontal rows across the front of the carapace.
Leg Characteristics
Long, moderately thick legs with visible spines and faint dark banding. The legs lack specialized sticky pads (scopulae) and are adapted for rapid running across surfaces rather than climbing vertical smooth glass.
Venom & Safety Information
Venom Information
Contains a cytotoxic venom that causes localized tissue necrosis in severe bites, though many envenomations are dry or result only in localized pain and redness.
Medical Significance
Historically considered medically significant due to potential necrotic lesions from bites, though modern studies suggest the severity may have been overstated. Bites can cause localized pain, induration, and slow-healing red lesions, requiring medical evaluation if symptoms worsen.
Safety Recommendations
Seal gaps around doors and windows, reduce clutter and woodpiles near the foundation, shake out shoes and clothing left on the floor, and gently relocate individuals outdoors using a cup and card if found inside.
Habitat & Behavior
Habitat & Range
Native to Europe and introduced to the Pacific Northwest of North America and parts of Central Asia. Found in damp, dark areas, low to the ground, around foundations, in woodpiles, rockeries, and occasionally inside homes in hidden crevices.
Behavior & Temperament
Aggressive when cornered or defending an egg sac, hence the species epithet 'agrestis'. They are fast runners and primarily nocturnal hunters, waiting inside their funnel retreats for prey to trigger trip-lines.
Diet & Prey
Generalist predators feeding on crawling insects such as beetles, cockroaches, earwigs, and other spiders that wander onto their sheet webs.
Seasonal Activity
Most active during late summer and autumn (August to October), which is when mature males actively wander in search of females, leading to increased human-spider encounters indoors.
Description
The Hobo Spider is a classic funnel weaver known for its fast movements and sheet-like webs found low to the ground. With its distinctive striped carapace and chevron-marked abdomen, it is an efficient nocturnal hunter of creeping pests in both natural and domestic environments.
Key Features
Long, spiny legs, longitudinal stripes on the carapace, distinctive chevron markings on the dorsal abdomen, and the construction of a non-sticky funnel web close to the ground.
Similar Species
Giant House Spider (Eratigena atrica) and Barn Funnel Weaver (Tegenaria domestica), which are generally larger and often lighter, requiring microscopic examination of genitalia for definitive differentiation.
Life Cycle
Females produce disc-shaped egg sacs in autumn, attaching them to sheltered surfaces near the web. Spiderlings hatch in spring, undergo multiple molting stages, and typically reach maturity within two years, with a total lifespan of up to three years.
Ecological Importance
Act as important apex invertebrate predators near the ground level, helping to naturally regulate populations of crawling household and garden pests.
Conservation Status
Not evaluated by the IUCN, but populations are stable and thriving across their native and introduced ranges.
Interesting Facts
Despite their intimidating reputation and common name 'Aggressive House Spider', they typically only bite when trapped tightly against human skin, such as being rolled over on in bed or trapped inside clothing.
Photography Tips
Use a macro lens with natural side lighting or a diffused flash to capture the fine details of the abdominal chevrons and carapace stripes, maintaining a safe distance while keeping the camera parallel to the spider.
Identified: 2026-08-29T13:57:30.765694