Hobo Spider, Aggressive House Spider
Eratigena agrestis
Agelenidae (Funnel-Weavers), Order Araneae
Physical Description
The hobo spider has a robust body with a distinct, elongated oval-shaped abdomen and a brownish cephalothorax that often features darker, indistinct longitudinal stripes. The body is relatively matte in appearance compared to some shiny spider species, covered in fine, inconspicuous hairs.
Size Estimate
Body length typically 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
The coloration is predominantly brown, ranging from yellowish-brown to dark brown. The abdomen features a distinct, chevron-shaped or zigzag pattern with the points facing forward, though these patterns can sometimes be faint.
Web Type
Builds a characteristic funnel-shaped sheet web close to the ground or in structural crevices, featuring a retreat tube where the spider waits for prey.
Eye Arrangement
Eight small, roughly equal-sized eyes arranged in two nearly straight horizontal rows.
Leg Characteristics
Long, robust legs that lack noticeable contrasting dark bands (unlike the Giant House Spider), covered in fine hairs and spines.
Venom & Safety Information
Venom Information
Contains cytotoxins that can cause localized necrosis or painful tissue reactions in rare cases, though human reactions vary widely.
Medical Significance
Historically considered dangerous due to suspected necrotic bites, modern arachnology views its medical significance as minimal, with symptoms often resembling a mild to moderate localized reaction.
Safety Recommendations
Seal cracks around foundations, clear vegetation away from walls, wear gloves when moving firewood, and safely relocate individuals using a cup and paper.
Habitat & Behavior
Habitat & Range
Native to Europe and introduced to the Pacific Northwest of North America. Prefers low-to-the-ground dark, moist crevices, rock piles, woodpiles, and foundational walls of houses.
Behavior & Temperament
Primarily nocturnal and a reluctant biter, the hobo spider typically only bites when trapped, squeezed, or heavily provoked.
Diet & Prey
Generalist predator feeding primarily on crawling insects such as beetles, roaches, ants, and earwigs caught near its funnel web.
Seasonal Activity
Most active during late summer and autumn, particularly when mature males wander actively in search of mates.
Description
The hobo spider is a quintessential funnel-weaver, known for its distinctive chevron markings and propensity for building sheet webs near ground level. While once heavily feared, modern research has helped clarify its temperament and actual venom impact.
Key Features
Uniformly colored legs lacking distinct dark bands, a chevron pattern on the abdomen, and construction of a low-lying funnel web.
Similar Species
Eratigena atrica (Giant House Spider) and Tegenaria domestica (Barn Funnel Weaver), distinguished by leg banding and precise epigynal or palpal structure.
Life Cycle
Females lay eggs in silk egg sacs hidden within the retreat during autumn, which overwinter and hatch in spring into spiderlings that disperse and mature by late summer.
Ecological Importance
Acts as an effective natural predator regulating populations of crawling pests around homes and gardens.
Conservation Status
Not evaluated by the IUCN; widespread, abundant, and locally invasive in introduced ranges.
Interesting Facts
Despite its specific epithet 'agrestis' meaning 'of the fields', it is frequently found in human habitations and basements.
Photography Tips
Photograph from above to clearly capture the dorsal abdominal chevron patterns and ensure the legs are fully visible without banding.
Identified: 2026-08-15T15:45:46.256415