Hobo Spider, Aggressive House Spider
Eratigena agrestis
Agelenidae (Funnel-Weavers), Order Araneae
Physical Description
Robust, elongated body with a distinct brownish cephalothorax featuring faint, lighter longitudinal stripes and a grayish-brown abdomen with a chevron pattern. Shows slight sexual dimorphism, with males possessing noticeably longer legs and enlarged palps.
Size Estimate
Body length ranges from 11 to 18 mm for females and 9 to 15 mm for males, with a total leg span reaching up to 40 mm. The photographed specimen appears to be a medium-sized adult.
Coloration & Markings
Dull brown, tan, and gray tones. The abdomen features a characteristic series of dark, distinct chevron or V-shaped markings pointing forward, unlike many other house spiders which lack clear patterns.
Web Type
Asymmetric sheet web that funnels into a tubular retreat where the spider hides, typically built in low, dark corners near the ground.
Eye Arrangement
Eight small eyes of roughly equal size arranged in two nearly straight horizontal rows across the front of the cephalothorax.
Leg Characteristics
Long, robust, and hairy legs with distinct spines but generally lacking prominent dark banding. Often held in a spread-eagled defensive or alert posture.
Venom & Safety Information
Venom Information
Cytotoxic venom containing proteins that can cause localized tissue necrosis, though human envenomation is uncommon and disputed in severity compared to historical claims.
Medical Significance
Historically considered dangerous due to potential necrotic bites, modern arachnology views its medical threat as low, often resulting in localized redness and pain similar to a bee sting, with rare necrotic reactions.
Safety Recommendations
Wear gloves when clearing dark, undisturbed storage areas or woodpiles, shake out shoes before wearing, and gently relocate spiders outdoors using a cup and card.
Habitat & Behavior
Habitat & Range
Native to Europe, introduced to the Pacific Northwest of North America and parts of Central Asia. Prefers dark, damp, undisturbed outdoor and indoor areas like woodpiles, foundations, and crawlspaces.
Behavior & Temperament
Crepuscular to nocturnal hunter. Reluctant to bite unless trapped or firmly pressed against the skin, contrary to its aggressive historical reputation.
Diet & Prey
Generalist predator feeding on crawling insects such as beetles, earwigs, flies, and other spiders trapped on its sheet web.
Seasonal Activity
Peak activity occurs in late summer and autumn, particularly during late August and September when mature males actively wander in search of mates.
Description
The hobo spider is a quintessential funnel-weaver, known for constructing dense sheet webs that end in a secure silken retreat. Though once feared for causing severe necrotic lesions, modern studies show it is generally docile and poses minimal risk to humans.
Key Features
Distinct chevron (V-shaped) markings on the dorsal abdomen, lack of dark banding on the legs, and association with a funnel-shaped sheet web near the ground.
Similar Species
Giant House Spider (Eratigena atrica) and Barn Funnel Weaver (Tegenaria domestica), distinguished primarily through microscopic examination of genital structures.
Life Cycle
Females produce disc-shaped egg sacs in autumn, hiding them within the web retreat. Spiderlings hatch in spring, undergoing multiple molts to reach maturity by late summer.
Ecological Importance
Serves as an effective natural pest controller by reducing populations of crawling insects around human structures and natural habitats.
Conservation Status
Not evaluated by the IUCN, but populations are stable and thriving, successfully expanding in introduced geographic ranges.
Interesting Facts
Despite the species name 'agrestis' meaning 'rural' in Latin, it frequently colonizes urban environments and human habitations, particularly in North America.
Photography Tips
Use a macro lens with adequate lighting from above or the side to highlight the abdominal chevrons while maintaining a safe distance from the retreat opening.
Identified: 2026-08-31T23:42:36.703089