Hobo Spider, Aggressive House Spider
Eratigena agrestis
Agelenidae (Funnel Web Weavers), Order Araneae
Physical Description
The spider has a robust body with a distinct brownish cephalothorax featuring darker linear markings, and an oblong, mottled brownish-grey abdomen. It has typical funnel-weaver proportions with visible spinnerets extending from the rear of the abdomen.
Size Estimate
Body length ranges from 11 to 15 millimeters for females and 8 to 11 millimeters for males, with a leg span reaching up to 40 millimeters.
Coloration & Markings
Predominantly brown with a complex pattern on the dorsal abdomen consisting of a central yellowish or pale chevron pattern. The legs are generally uniform brown without distinct dark banding.
Web Type
Builds a characteristic non-sticky funnel web that features a sheet-like platform leading into a tubular retreat where the spider waits for prey.
Eye Arrangement
Eight eyes arranged in two slightly curved horizontal rows of four, all of roughly similar size, which is typical for funnel web weavers.
Leg Characteristics
Legs are moderately long, robust, and covered in fine hairs and spines, typically held in a splayed posture when resting on the web.
Venom & Safety Information
Venom Information
Contains a cytotoxic venom designed to immobilize insect prey. Historically implicated in necrotic wounds, though current medical consensus debates the severity of human envenomation.
Medical Significance
Historically considered dangerous due to suspected necrotic bites (hoboism), modern research suggests their medical significance is often overstated, though bites can cause localized pain, redness, and hard swelling.
Safety Recommendations
Wear gloves when moving firewood or cleaning dark basements, seal home entry points, and gently relocate spiders outdoors using a glass and cardboard.
Habitat & Behavior
Habitat & Range
Native to Europe and introduced to the Pacific Northwest of North America. Found in moist, dark areas such as under rocks, in woodpiles, and frequently near ground level in human dwellings.
Behavior & Temperament
Crepuscular to nocturnal hunter. They are generally defensive rather than aggressive, biting usually only when trapped against human skin.
Diet & Prey
Primarily feeds on ground-dwelling insects such as beetles, flies, and silverfish trapped on the sheet web.
Seasonal Activity
Most active during late summer and autumn, particularly males wandering in search of females during mating season.
Description
The Hobo Spider is a classic funnel weaver known for its ground-level habitat and distinctive sheet-like webs. While often feared due to past misconceptions regarding its venom, it is a beneficial predator that helps control household and garden insect populations.
Key Features
Uniformly colored legs lacking distinct dark bands, a chevron pattern on the abdomen, and construction of a funnel-shaped retreat web.
Similar Species
Giant House Spider (Eratigena atrica) and Domestic House Spider (Tegenaria domestica), which can be distinguished by subtle genital morphology and leg banding patterns.
Life Cycle
Females produce flat, disc-like silk egg sacs in the autumn, depositing dozens of eggs that overwinter and hatch in the spring.
Ecological Importance
Serves as an effective predator of crawling household and garden pests, contributing to natural pest control.
Conservation Status
Not evaluated by the IUCN, but populations are secure and expanding in introduced ranges.
Interesting Facts
Despite its specific epithet 'agrestis' meaning 'rural', this species is frequently found in urban environments and was likely introduced via maritime shipping.
Photography Tips
Use macro lenses with good side lighting to highlight the abdominal chevron patterns and cephalothorax markings while maintaining a safe distance.
Identified: 2026-09-22T04:03:49.311652