Hobo Spider, Aggressive House Spider
Eratigena agrestis
Agelenidae (Funnel Weavers), Order Araneae
Physical Description
Robust body with a distinctly marked brownish carapace and an elongated, oblong abdomen showing a pattern of chevron-like markings. The specimen appears flattened or curled defensively, typical of an interrupted or deceased ground-dwelling spider.
Size Estimate
Body length approximately 11-15 mm, with a leg span reaching up to 40-45 mm. This specimen is an adult.
Coloration & Markings
Mottled brown and gray coloration. The cephalothorax features indistinct lighter and darker stripes, while the dorsal abdomen displays a clear herringbone or chevron pattern pointing forward.
Web Type
Funnel web (sheet web). Constructs a dense, flat sheet of silk leading into a tubular retreat where the spider waits for passing prey.
Eye Arrangement
Eight small, dark eyes of roughly equal size arranged in two slightly curved, horizontal rows of four across the front of the carapace.
Leg Characteristics
Long, robust legs with visible spines and faint banding. The legs lack distinct contrasting rings found in some related species, showing uniform brown tones.
Venom & Safety Information
Venom Information
Contains cytotoxins and proteolytic enzymes. A bite can cause localized pain, tissue necrosis (dermonecrosis) in some cases, and lingering headaches.
Medical Significance
Historically considered medically significant due to fears of necrotic bites, though modern arachnological consensus suggests severe necrotic reactions are rare and often misattributed.
Safety Recommendations
Wear gloves when moving stacked firewood or clearing dark basements. Shake out shoes and clothing left on the floor. Relocate spiders using a container and a piece of card.
Habitat & Behavior
Habitat & Range
Originating in Europe and introduced to the Pacific Northwest of North America and parts of Central Asia. Found in rough terrain, grassy fields, foundations, and dark, damp corners of homes and garages.
Behavior & Temperament
Defensive rather than aggressive, typically biting only when trapped against human skin or squeezed. Fast-running ground hunter that relies on its web to detect vibrations.
Diet & Prey
Generalist predator feeding on crawling insects such as beetles, flies, roaches, and occasionally other spiders.
Seasonal Activity
Most active during late summer and autumn when mature males wander extensively in search of females to mate with.
Description
The hobo spider is a robust brown funnel weaver well-known in urban folklore. While its bite carries a controversial reputation regarding tissue damage, it is a shy creature that prefers dark crevices and damp retreats over confronting humans.
Key Features
Absence of distinct dark rings on the legs, a clearly defined chevron pattern on the abdomen, and construction of a funnel-shaped retreat.
Similar Species
Giant House Spider (Eratigena atrica) and Barn Funnel Weaver (Tegenaria domestica), distinguished primarily by subtle genital morphology and leg markings.
Life Cycle
Females lay eggs in silk cocoons hidden in protected retreats during late summer. Spiderlings overwinter and mature by the following summer, living for up to two to three years.
Ecological Importance
Acts as an effective natural population controller for various agricultural and household insect pests.
Conservation Status
Not threatened; secure and expanding its introduced range in North America.
Interesting Facts
Despite its specific epithet 'agrestis' meaning 'rural' or 'field', the hobo spider frequently thrives in human-altered landscapes and stone foundations.
Photography Tips
Photograph from above to capture the distinct abdominal chevrons and eye arrangement. Ensure good lighting without harsh shadows to highlight the subtle leg and carapace patterns.
Identified: 2026-08-29T01:09:46.152762