Hobo Spider, Aggressive House Spider
Eratigena agrestis
Agelenidae (Funnel-Weavers), Order Araneae. Key family characteristics include long spinnerets and a typical preference for building sheet webs with a funnel-shaped retreat.
Physical Description
Elongated body with a light brown, patterned abdomen and a distinctively yellowish-brown cephalothorax featuring darker linear markings. The surface texture is finely haired.
Size Estimate
Body length ranges from 11 to 14 mm for females and 9 to 12 mm for males, with a substantial leg span reaching up to 40 mm.
Coloration & Markings
Muted brown tones with a distinctive chevron or herringbone pattern along the dorsal side of the abdomen. The sternum features a light median stripe.
Web Type
Builds a dense, non-sticky horizontal sheet web with a tubular retreat funnel at one end where the spider waits for prey.
Eye Arrangement
Eight small, dark eyes arranged in two slightly curved, nearly parallel horizontal rows of four.
Leg Characteristics
Long, robust legs without distinct dark banding, covered in fine setae and small spines. Often held flat against the surface in a splayed posture.
Venom & Safety Information
Venom Information
Contains a localized necrotic venom, though its medical significance and reputation for causing severe dermonecrotic lesions have been heavily debated and largely downgraded by modern toxicological studies.
Medical Significance
Historically considered dangerous due to suspected necrotic bites, but current medical consensus views its bite as generally resulting in mild localized pain, redness, and occasionally a temporary hard swelling.
Safety Recommendations
Wear gloves when moving woodpiles or clearing dark basement corners. Catch and release indoor specimens using a cup and stiff paper.
Habitat & Behavior
Habitat & Range
Native to Europe and introduced to the Pacific Northwest of North America. Prefers dark, damp areas near ground level, foundations, woodpiles, and tall grass.
Behavior & Temperament
Fast-moving, ground-dwelling hunting strategy using a funnel web. Generally defensive rather than aggressive, biting mostly when trapped or squeezed against skin.
Diet & Prey
Primarily consumes crawling insects such as beetles, roaches, flies, and other spiders trapped on its sheet web.
Seasonal Activity
Most active during late summer and autumn, particularly males wandering in search of mates.
Description
The Hobo Spider is a classic funnel-weaver known for its rapid movements and distinct chevron patterns. While its historical reputation caused widespread concern, it is now understood to be a reluctant biter that plays a valuable role in controlling insect populations around human habitations.
Key Features
Absence of distinct dark banding on the legs, presence of a clear herringbone pattern on the abdomen, and the construction of a non-sticky funnel sheet web.
Similar Species
Giant House Spider (Eratigena atrica) and Domestic House Spider (Tegenaria domestica). Distinguished primarily by genital examination or subtle differences in coloration and size.
Life Cycle
Females produce disc-shaped egg sacs in late summer or autumn, containing around 50 to 100 eggs. Spiderlings overwinter and mature by the following summer. Total lifespan typically spans up to two years.
Ecological Importance
Acts as an effective natural predator for ground-dwelling pest insects, helping regulate populations of flies, beetles, and roaches in and around structures.
Conservation Status
Not evaluated by the IUCN, but secure and locally abundant across its native and introduced ranges.
Interesting Facts
Despite its species name 'agrestis' meaning 'rural' or 'of the fields', it frequently colonizes urban environments and human structures in introduced ranges.
Photography Tips
Use macro lenses with a fast shutter speed to capture fast movements. Shoot from the side to highlight the abdominal chevron patterns and leg structure.
Identified: 2026-09-20T21:37:58.397047