Hobo Spider, Aggressive House Spider
Eratigena agrestis
Agelenidae (Funnel-Weavers), Order Araneae. Key family characteristics include three pairs of spinnerets with the posterior pair being noticeably elongated, and building sheet webs that end in a funnel-shaped retreat.
Physical Description
The spider has a distinctively robust body with a pear-shaped, slightly elongated brownish abdomen and a darker brown cephalothorax featuring characteristic darker longitudinal stripes or patterns. The body surface appears finely hairy rather than spiny.
Size Estimate
Body length typically ranges from 11 to 18 mm for females and 9 to 15 mm for males, with a leg span reaching up to 40 mm. This specimen appears to be an adult or sub-adult.
Coloration & Markings
Predominantly brown with a mottled or patterned grayish-brown abdomen often featuring a series of distinct chevron or herringbone markings down the dorsal midline. The sternum typically lacks distinct light markings.
Web Type
Builds a characteristic non-sticky horizontal sheet web with a tubular funnel retreat at one corner or edge where the spider waits for prey.
Eye Arrangement
Eight small eyes of roughly equal size arranged in two slightly curved, nearly parallel horizontal rows across the front of the cephalothorax.
Leg Characteristics
Long, robust, and visibly hairy legs without conspicuous contrasting dark or light banding. The legs are held in a typical sprawling posture common to funnel-weavers.
Venom & Safety Information
Venom Information
Possesses a proteinaceous venom. While historically reputed to cause necrotic lesions similar to the brown recluse, modern arachnology indicates that bites typically result only in localized pain, redness, and temporary discomfort.
Medical Significance
Low to moderate medical significance. Bites are uncommon and usually occur only when the spider is pressed directly against the skin. Symptoms generally include localized pain and mild swelling, but severe necrotic reactions are rare or disputed.
Safety Recommendations
Avoid handling spiders with bare hands, wear gloves when moving firewood or cleaning dark storage spaces, and gently relocate unwanted indoor spiders outdoors using a cup and a piece of card.
Habitat & Behavior
Habitat & Range
Native to Europe and introduced to the Pacific Northwest of North America and parts of Central Asia. Found in grassy fields, under rocks, woodpiles, and frequently in human habitations, particularly in dark, damp areas like basements and crawl spaces.
Behavior & Temperament
Primarily nocturnal and a ground-dwelling hunter that relies on its web to detect vibrations of passing prey. They are defensive rather than aggressive, typically attempting to flee unless cornered or trapped against skin.
Diet & Prey
Feeds on a wide variety of ground-dwelling and flying insects, using its sheet web as a sensory platform to detect and rush out to capture prey.
Seasonal Activity
Most active during late summer and autumn when mature males wander actively in search of females, leading to a higher rate of human encounters during these months.
Description
The Hobo Spider is a sturdy brown funnel-weaver known for constructing sheet webs in dark corners, both outdoors and inside human structures. Although historically feared due to exaggerated claims regarding its venom, it is generally a shy, nocturnal hunter that provides natural pest control against household insects.
Key Features
Distinguished by the lack of distinct leg banding, the presence of chevron markings on the abdomen, and the construction of a non-sticky funnel sheet web rather than an orb or cobweb.
Similar Species
Can be confused with the Giant House Spider (Eratigena atrica) and the Domestic Funnel Weaver (Tegenaria domestica). Distinguishing often requires microscopic examination of the genitalia, though E. agrestis usually has more pronounced chevron patterns on the abdomen.
Life Cycle
Females produce disc-shaped egg sacs in the autumn, attaching them in sheltered areas near the web. Spiderlings hatch in the spring, undergo multiple molts to reach maturity within two years, and typically complete their life cycle after mating.
Ecological Importance
Acts as an effective predator of ground-dwelling insects and arthropods, helping to regulate pest populations in both natural and domestic environments.
Conservation Status
Not evaluated by the IUCN, but populations are secure and widespread, often benefiting from human-modified environments.
Interesting Facts
Despite its specific epithet 'agrestis' meaning 'of the fields', it is frequently encountered in human environments. They are poor climbers and generally unable to scale smooth vertical surfaces like glass or polished bathtubs.
Photography Tips
Use a macro lens with adequate lighting from the side to highlight the abdominal chevron patterns and cephalothorax markings. Maintain a safe distance and photograph from a low angle parallel to the surface.
Identified: 2026-09-12T05:35:00.576979