Hobo Spider, Aggressive House Spider
Eratigena agrestis
Agelenidae (Funnel-Weavers), Order Araneae. Key family characteristics include long spinnerets and building sheet-like webs that end in a funnel retreat.
Physical Description
The hobo spider has a brownish, elongated body with relatively long legs. The cephalothorax is brown with darker longitudinal stripes or patterns, while the abdomen is brownish-gray with a distinct, often chevron-shaped pattern (herringbone pattern) running down the dorsal side.
Size Estimate
Body length typically ranges from 11 to 18 mm for females and 8 to 14 mm for males. Total leg span can reach up to 40 to 45 mm. This specimen appears to be an adult.
Coloration & Markings
Mostly brown with mottled grayish-brown markings. The defining feature is the distinct chevron or herringbone pattern on the dorsal abdomen, with the central points of the chevrons pointing forward.
Web Type
Builds a characteristic non-sticky sheet web that extends outward from a tubular retreat or funnel where the spider hides, usually located near the ground or in dark corners.
Eye Arrangement
Eight small eyes of roughly equal size, arranged in two slightly curved, nearly parallel horizontal rows across the front of the cephalothorax, typical of the Agelenidae family.
Leg Characteristics
Long, robust legs of uniform brown color without distinct contrasting dark banding or rings, covered in fine hairs and visible spines.
Venom & Safety Information
Venom Information
Contains a necrotic or cytotoxic venom component, though its medical significance has been heavily debated in scientific literature compared to other dangerous spiders.
Medical Significance
Historically considered dangerous due to suspected necrotic lesions, modern toxicology and arachnology studies suggest hobo spider bites rarely cause severe necrosis in humans, often resulting only in localized redness and pain.
Safety Recommendations
Reduce clutter around foundations, seal cracks and crevices in the home, wear gloves when moving firewood, and gently relocate spiders outdoors using a cup and paper.
Habitat & Behavior
Habitat & Range
Native to Europe and introduced to the Pacific Northwest of North America and parts of Central Asia. Found in moist, dark areas, woodpiles, tall grass, and occasionally inside homes near baseboards or basements.
Behavior & Temperament
Crepuscular to nocturnal hunters that spend most of their time waiting in their funnel webs. They are defensive rather than aggressive, biting mostly when trapped or squeezed against human skin.
Diet & Prey
Generalist predator feeding on crawling insects such as beetles, flies, roaches, and earwigs that stumble onto their sheet webs.
Seasonal Activity
Most active during late summer and autumn, particularly around August to October when mature males actively wander in search of females.
Description
The hobo spider is a medium-sized brown funnel-weaver widely recognized in regions of the Pacific Northwest. Known for its distinct herringbone abdominal pattern and lack of banded legs, it constructs sheet webs near ground level and relies on quick dashes to capture passing prey.
Key Features
Distinct herringbone pattern on the abdomen, uniform brown legs without bands, and construction of a horizontal funnel web.
Similar Species
Giant House Spider (Eratigena atrica) and Domestic House Spider (Tegenaria domestica). Distinguished by subtle differences in genital structures and slightly different abdominal patterns.
Life Cycle
Females lay eggs in silk egg sacs hidden within the funnel retreat in late summer or autumn. Spiderlings hatch the following spring, undergo multiple molts, and reach maturity in one to two years.
Ecological Importance
Serves as an effective predator of various household and garden insect pests, helping to naturally regulate insect populations.
Conservation Status
Not evaluated by the IUCN, but populations are stable and thriving, especially in introduced ranges.
Interesting Facts
Despite the common name 'aggressive house spider' derived from a mistranslation of the species name 'agrestis' (meaning rural or of the fields), these spiders are generally timid and flee rather than attack.
Photography Tips
Photograph from a dorsal angle to clearly capture the herringbone pattern on the abdomen and the lack of leg banding. Use natural lighting or diffused flash to avoid harsh shadows.
Identified: 2026-09-08T22:06:37.914089