Hobo Spider, Field Spider
Eratigena agrestis
Agelenidae (Funnel Web Weavers), Order Araneae. Key family characteristics include long spinnerets and a distinctive funnel-shaped retreat.
Physical Description
The spider has a relatively elongated, softly hairy body with a light brown cephalothorax featuring darker lateral stripes or markings, and a distinct patterned abdomen. The specimen shown is an adult male, easily identifiable by the enlarged bulbous pedipalps at the front used for mating.
Size Estimate
Body length ranges from 11 to 14 mm for females and 9 to 12 mm for males. The leg span is roughly 35 to 45 mm. This specimen is an adult male.
Coloration & Markings
Brown base coloration with a mottled or checkered pattern of yellowish-brown and dark brown on the abdomen. The cephalothorax typically lacks distinct dark bands in some populations, but generally shows subtle longitudinal striping.
Web Type
Builds a dense, non-sticky sheet web that extends outward from a tubular retreat (funnel) where the spider hides, typically constructed near ground level in dark, protected areas.
Eye Arrangement
Eight small eyes of roughly equal size arranged in two slightly curved, more or less parallel rows across the front of the carapace.
Leg Characteristics
Long, moderately robust legs with visible hairs and spines. Unlike some other funnel weavers, the legs of Eratigena agrestis generally lack prominent dark banding, appearing uniformly brownish.
Venom & Safety Information
Venom Information
Contains a necrotic venom similar to other related species, though its potency and significance in human envenomation remain a subject of ongoing debate among arachnologists and toxicologists.
Medical Significance
Historically feared for causing necrotic lesions similar to the brown recluse, modern medical consensus suggests that bites usually result in mild to moderate localized pain, redness, and occasionally localized tissue irritation or minor necrosis, though severe reactions are rare.
Safety Recommendations
Wear gloves when moving firewood, clear clutter from basements, seal cracks around doors and windows, and gently relocate wandering spiders outdoors using a cup and piece of paper.
Habitat & Behavior
Habitat & Range
Native to Europe and introduced to the Pacific Northwest of North America and parts of Central Asia. Found in rough grass fields, along stone walls, woodpiles, and frequently near or inside human habitations, particularly in dark, damp basements or crawlspaces.
Behavior & Temperament
Fast-moving, ground-dwelling hunters that rely on their sheet webs to detect vibrations of passing prey. They are defensive when cornered or trapped against skin, but generally tend to flee rather than attack.
Diet & Prey
Primarily feeds on ground-dwelling insects such as beetles, flies, earwigs, and silverfish trapped on the horizontal sheet web.
Seasonal Activity
Most commonly seen in late summer and autumn (August to October), when mature males actively wander in search of females, frequently stumbling into homes.
Description
The Hobo Spider is a classic European native that has established itself in parts of North America. Known for its distinct funnel webs near the ground, this brownish spider is a capable nocturnal hunter. While possessing a fearsome reputation in folklore regarding its venom, it is generally reclusive and prefers to escape rather than bite.
Key Features
Uniformly brownish legs lacking distinct dark bands, a patterned chevron-like design on the abdomen, and prominent male pedipalps (in males) distinguish this species from other house-dwelling spiders.
Similar Species
Giant House Spider (Eratigena atrica) and Domestic House Spider (Tegenaria domestica). Distinguished primarily by subtle genital differences, exact abdominal markings, and leg banding patterns.
Life Cycle
Females construct tough, disc-shaped egg sacs in the autumn, depositing dozens of eggs. Spiderlings hatch in the spring and undergo multiple molts, reaching maturity by late summer when males wander in search of mates.
Ecological Importance
Acts as an effective natural predator for various crawling household and garden insect pests, helping to regulate local insect populations.
Conservation Status
Not evaluated by the IUCN, but populations are secure and expanding in introduced regions.
Interesting Facts
The common name 'hobo' comes from the belief that they traveled along railway lines and roadsides to expand their range, though they actually spread primarily through human transport of materials.
Photography Tips
Use macro lenses with a high depth of field to capture eye arrangement and abdominal patterns clearly. Ensure safe containment or distance, and photograph from above to capture dorsal markings without causing the spider distress.
Identified: 2026-09-23T16:14:26.059994