Hobo Spider, Aggressive House Spider
Eratigena agrestis
Agelenidae (Funnel Web Weavers), Order Araneae. Key family characteristics include the construction of sheet-like webs that lead to a tubular retreat, and relatively long spinnerets visible at the rear of the abdomen.
Physical Description
The spider has a elongated, oval-shaped abdomen and a distinct cephalothorax. The body texture is finely hairy. While sexual dimorphism is present with females generally being slightly larger and broader-abdomened, the specimen in the image is curled in a defensive posture, making exact proportion assessment difficult.
Size Estimate
Body length typically ranges from 11 to 18 mm for females and 9 to 15 mm for males. The leg span can reach up to 40 mm. The specimen shown appears to be a medium-sized adult or a late-stage sub-adult.
Coloration & Markings
Base coloration is generally brownish, featuring a distinctive pattern of yellowish, chevron-like markings (herringbone pattern) on the dorsal side of the abdomen pointing forward.
Web Type
Builds a dense, non-sticky sheet web that terminates in a funnel-like retreat where the spider hides, typically constructed at ground level or near baseboards.
Eye Arrangement
Eight small eyes of similar size arranged in two slightly curved, more or less parallel horizontal rows across the front of the carapace.
Leg Characteristics
Legs are moderately long, robust, and covered in fine hairs and spines without distinct dark banding. They lack prominent specialized claw tufts.
Venom & Safety Information
Venom Information
Contains cytotoxins. Historically feared as potently necrotic, modern arachnological studies suggest their venom potency is often exaggerated, though bites can cause localized pain, redness, and hard swelling.
Medical Significance
Historically considered medically significant due to suspected necrotic reactions, but contemporary medical and arachnological consensus views severe necrotic symptoms as rare or misdiagnosed. Bites cause moderate local pain and a temporary hard lesion, but are not life-threatening. Seek medical attention if a secondary infection develops.
Safety Recommendations
Wear gloves when moving firewood or cleaning dark basements. Seal gaps around doors and windows. If a spider is found inside, relocate it outdoors using a cup and a piece of paper.
Habitat & Behavior
Habitat & Range
Found throughout the Pacific Northwest of the United States, including Washington state, as well as parts of Canada and Europe. Prefers dark, damp, undisturbed areas such as woodpiles, tall grass, and indoors along baseboards or in basements.
Behavior & Temperament
Primarily ground-dwelling and nocturnal. They are relatively defensive if cornered or trapped against the skin, but generally tend to flee rather than attack.
Diet & Prey
Feeds on a variety of ground-dwelling insects including beetles, flies, and other spiders, subduing them in their funnel webs.
Seasonal Activity
Most commonly encountered in late summer and autumn (August to October) when mature males actively wander in search of mates.
Description
The Hobo Spider is a common sight in the Pacific Northwest, often found scurrying along floors or hiding in dark corners. Though it has carried an intimidating reputation, it is a shy, ground-dwelling creature whose primary goal is avoiding human contact while managing pest insect populations.
Key Features
Distinctive herringbone or chevron pattern on the abdomen, lack of distinct banding on the legs, and association with a funnel-shaped web near ground level.
Similar Species
Giant House Spider (Eratigena atrica) and Domestic House Spider (Tegenaria domestica). Distinguished primarily by subtle genital morphology or slightly different abdominal pattern nuances.
Life Cycle
Females construct disc-shaped egg sacs in the autumn, depositing dozens of eggs that overwinter. Spiderlings hatch in spring, undergo multiple molts, and reach adulthood by late summer when mating occurs.
Ecological Importance
Serves as an effective predator of ground-dwelling insects, contributing significantly to natural pest control in gardens, fields, and around homes.
Conservation Status
Not evaluated by the IUCN, but populations are stable and thriving, successfully colonizing new temperate urban and rural environments.
Interesting Facts
Introduced to the Pacific Northwest from Europe via shipping crates, the hobo spider earned an unearned reputation as a fearsome biter due to conflation with other spider species.
Photography Tips
Use macro lenses with natural diffused lighting or a ring flash. Capture dorsal views to clearly show the abdominal chevron pattern and eye arrangement from the front.
User Notes
Washington state
Identified: 2026-10-12T06:39:29.541054