Hobo Spider, Aggressive House Spider
Eratigena agrestis
Agelenidae (Funnel-Weavers), Order Araneae. Key family characteristics include three pairs of spinnerets with the posterior pair being noticeably elongated, and building sheet webs that end in a funnel-shaped retreat.
Physical Description
The spider has a distinct oblong abdomen and a relatively uniform brown cephalothorax. It features a finely haired texture without dramatic coloration contrasts, and the body proportions show moderately long, sturdy legs radiating outward. Males have visibly enlarged palps.
Size Estimate
Body length ranges from 11 to 15 mm for females and 9 to 12 mm for males, with a total leg span reaching roughly 35 to 45 mm. This specimen appears to be a medium-sized adult or a well-developed sub-adult.
Coloration & Markings
Predominantly brown overall. The cephalothorax typically lacks distinct dark stripes (unlike some relatives), while the dorsal abdomen features a pattern of yellowish, chevron-like markings pointing forward. Legs are generally a uniform brown without strong banding.
Web Type
Builds a dense, non-sticky sheet web that terminates in a tubular or funnel-shaped retreat where the spider lurks, frequently found near the ground in dark, undisturbed corners.
Eye Arrangement
Arranged in two horizontal rows of four eyes each, all roughly equal in size and positioned closely together across the front of the carapace, typical of the funnel-weaver family.
Leg Characteristics
Legs are moderately long, stout, and covered with fine hairs and spines. They are held flat against the surface in a typical resting posture and lack specialized structures like distinct color bands.
Venom & Safety Information
Venom Information
Possesses a necrotic venom, though its medical potency and significance have been heavily debated. Envenomation can cause localized pain, redness, and occasionally localized tissue necrosis.
Medical Significance
Historically considered dangerous due to potential necrotic bite effects, though current arachnological consensus suggests many attributed symptoms are misdiagnosed or secondary infections. Bites are uncommon and typically occur only when trapped against human skin.
Safety Recommendations
Reduce clutter around foundations, seal entry points, and wear gloves when moving stored items. If a bite occurs, clean the area and monitor for symptoms, seeking medical attention if necrosis or severe local reactions develop.
Habitat & Behavior
Habitat & Range
Originally native to Europe and Central Asia, introduced to the Pacific Northwest of North America. Prefers dark, cool, low-to-the-ground areas such as baseboards, woodpiles, rockeries, and crawl spaces.
Behavior & Temperament
Generally non-aggressive, fleeing when disturbed. They are active hunters within their webs, primarily nocturnal, and wander in search of mates during late summer and autumn.
Diet & Prey
Feeds opportunistically on crawling insects including roaches, beetles, earwigs, and silverfish trapped on the horizontal sheet web.
Seasonal Activity
Most active during late summer and autumn, particularly around August through October, when mature males actively wander in search of females.
Description
The hobo spider is a robust funnel-weaver commonly encountered in human dwellings and gardens within its introduced range. Recognized by its brownish chevron-patterned abdomen and sheet-like webs, it plays an important role in controlling domestic insect populations.
Key Features
Uniform brown coloration, distinct chevron markings on the dorsal abdomen, lack of strong leg banding, and construction of a funnel-shaped sheet web near ground level.
Similar Species
Giant House Spider (Eratigena atrica) and domestic house spider (Tegenaria domestica). Distinguished by subtle differences in epigyne and male palpal structures, as well as geographic location and specific cephalothorax markings.
Life Cycle
Females produce disc-shaped egg sacs in autumn, attaching them to sheltered surfaces. Spiderlings hatch in spring, undergo multiple molts, and reach maturity by the following year with a typical lifespan of 1 to 2 years.
Ecological Importance
Serves as an effective predator of household and garden insect pests, helping regulate populations of crawling arthropods while acting as prey for larger insectivores and birds.
Conservation Status
Not evaluated by the IUCN, but populations are secure, abundant, and locally invasive in parts of North America.
Interesting Facts
Despite its specific epithet 'agrestis' (meaning rural or of the fields), it has successfully adapted to urban environments. The common name 'hobo' actually stems from an early mistaken belief that they traveled along railway lines.
Photography Tips
Use a macro lens with good side lighting to highlight the abdominal chevrons and eye arrangement. Maintain a safe distance and photograph from above while avoiding sudden movements that might cause the spider to retreat into its funnel.
Identified: 2026-09-10T17:12:43.349803