Hobo Spider, Aggressive House Spider
Eratigena agrestis
Agelenidae (Funnel Web Weavers), Order Araneae. Key family characteristics include three pairs of spinnerets with the posterior pair significantly elongated, and distinctive funnel-shaped sheet webs.
Physical Description
The hobo spider has a robust body with a distinct, elongated, brownish-grey cephalothorax featuring darker parallel stripes or markings. The abdomen is oval, greyish-brown, and often marked with a distinctive chevron pattern pointing forward. It possesses visible, elongated spinnerets at the rear of the abdomen.
Size Estimate
Body length typically ranges from 11 to 18 millimeters for females and 9 to 15 millimeters for males. The total leg span can reach up to 40 to 45 millimeters. This appears to be an adult specimen.
Coloration & Markings
Predominantly brown, greyish-brown, and yellowish-brown tones. The abdomen features a series of distinct dark chevrons (V-shaped markings) along the centerline. Unlike some other house spiders, the legs are usually a solid, uniform brown color without distinct banding.
Web Type
Constructs a characteristic dense, flat sheet web that terminates in a funnel-shaped retreat where the spider hides, waiting for prey. The web is non-sticky and typically built low to the ground in dark, protected corners.
Eye Arrangement
Features eight small eyes of roughly equal size arranged in two slightly curved, nearly parallel horizontal rows across the front of the carapace, typical of the funnel-weaver family.
Leg Characteristics
Long, robust legs covered in visible hairs and fine spines. The legs are generally uniform in color without noticeable rings or bands, adapted for rapid sprinting across surfaces rather than climbing smooth vertical walls.
Venom & Safety Information
Venom Information
Possesses a necrotic venom that was historically suspected of causing severe tissue damage, though modern arachnological studies debate its true severity and often attribute complex necrotic symptoms to secondary infections or other causes.
Medical Significance
Historically classified as medically significant due to fears of necrotic lesions (hoboism), but current medical and scientific consensus suggests its bite generally causes mild to moderate localized pain, redness, and swelling, akin to a bee sting, rarely resulting in significant necrosis.
Safety Recommendations
Avoid handling spiders with bare hands, wear gloves when moving stacked firewood or clearing dark basements, and safely relocate indoor spiders using a cup and piece of paper. First aid for bites includes washing the area with soap and water and applying a cool compress.
Habitat & Behavior
Habitat & Range
Native to Europe and introduced to the Pacific Northwest of North America. Prefers undisturbed, dark areas outdoors in tall grass, rock piles, or woodpiles, and frequently enters human structures, living in basements, crawlspaces, or corners.
Behavior & Temperament
Crepuscular to nocturnal hunter that spends most of its time hidden inside the funnel retreat of its web. They are defensive rather than aggressive, biting usually only when trapped, squeezed, or accidentally compressed against human skin.
Diet & Prey
Generalist predator feeding on crawling insects such as beetles, flies, roaches, and other spiders that stumble onto the horizontal sheet web.
Seasonal Activity
Most active during late summer and autumn (August to October), which corresponds to the adult mating season when wandering males actively search for females.
Description
The hobo spider is a robust, fast-running funnel weaver known primarily for its distinctive chevron markings and preference for ground-level habitats. While often feared due to past reputations regarding necrotic bites, it is generally a shy, reclusive inhabitant of dark corners that plays a valuable role in reducing household insect populations.
Key Features
Uniformly colored legs without banding, a distinctive pattern of dark chevrons on the dorsal abdomen, elongated posterior spinnerets, and construction of a flat funnel web near the ground.
Similar Species
Giant House Spider (Eratigena atrica) and Domestic House Spider (Tegenaria domestica). E. atrica is generally larger with banded legs, while T. domestica has more distinct banding on both legs and palps.
Life Cycle
Females produce disc-shaped egg sacs in the autumn, attaching them to protected surfaces near the web. Eggs overwinter, and spiderlings hatch in spring. They mature over two years, with adults typically dying off by late autumn.
Ecological Importance
Acts as an effective natural predator of household and garden pests, helping to control populations of insects like roaches, earwigs, and flies, while serving as a food source for larger predators.
Conservation Status
Not evaluated by the IUCN, but populations are stable, widespread, and successfully established in their introduced North American ranges.
Interesting Facts
Despite the common name 'hobo spider,' the name does not derive from wandering vagrants, but rather from the Latin word 'agrestis,' meaning 'of the fields.' They are notoriously poor climbers and frequently fall into bathtubs or sinks, unable to climb back out.
Photography Tips
Photograph from a safe distance using a macro lens with natural or diffused lighting. Capture dorsal views to clearly show the abdominal chevron pattern and facial shots to record eye arrangements and palps.
Identified: 2026-08-16T09:48:49.970884