Hobo Spider, Field Spider
Eratigena agrestis
Agelenidae (Funnel-weave spiders), Order Araneae
Physical Description
Elongated body shape with a distinct oval-shaped abdomen and a somewhat flattened, patterned cephalothorax. The surface has fine hairs rather than heavy spines. It features prominent, forward-facing palps near the front.
Size Estimate
Body length typically ranges from 11 to 18 mm for females and 9 to 15 mm for males, with a total leg span reaching up to 40 to 45 mm. This specimen appears to be an adult.
Coloration & Markings
Mottled brown coloration with a distinctive herringbone or chevron pattern of light and dark markings running down the dorsal side of the abdomen. The cephalothorax features yellowish-brown longitudinal stripes.
Web Type
Builds a characteristic funnel-shaped sheet web near the ground in dark, protected places, utilizing a retreat tube 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 legs covered in fine hairs and weak spines. Unlike many spiders, the legs typically lack distinct dark banding or rings, maintaining a uniform light brown color.
Venom & Safety Information
Venom Information
Contains a cytotoxic venom designed to immobilize insect prey. Historically reputed to cause necrotic lesions, though modern clinical toxicology suggests bites result primarily in localized pain and redness.
Medical Significance
Historically considered dangerous due to suspected necrotic bites, but recent consensus classifies it as of minor medical significance, primarily causing localized pain, swelling, and temporary redness similar to a bee sting.
Safety Recommendations
Wear gloves when moving stored items in dark areas, shake out shoes left outside, and safely relocate indoor spiders outdoors using a cup and stiff paper.
Habitat & Behavior
Habitat & Range
Native to Europe and introduced to the Pacific Northwest of North America. Prefers undisturbed, low-lying outdoor areas like fields, tall grass, and under rocks, but frequently wanders indoors into basements and crawlspaces.
Behavior & Temperament
Fast-running, ground-dwelling hunters that are typically non-aggressive toward humans. They will only bite defensively when trapped against the skin or heavily provoked.
Diet & Prey
Primarily feeds on crawling ground insects such as beetles, roaches, flies, and other spiders, using its funnel web to detect vibrations from passing prey.
Seasonal Activity
Most active during late summer and autumn, particularly around August to October when mature males actively wander in search of mates.
Description
The Hobo Spider is a swift and agile hunter known for constructing intricate funnel webs close to the ground. Though once feared for its potent reputation, it is a beneficial predator that helps keep insect populations in check around gardens and structural perimeters.
Key Features
Uniformly colored brown legs lacking dark bands, a distinct herringbone pattern on the abdomen, and construction of a non-sticky funnel-shaped retreat web.
Similar Species
Giant House Spider (Eratigena atrica) and Domestic House Spider (Tegenaria domestica), which are generally larger or display different leg banding and abdominal markings.
Life Cycle
Females construct tough, disc-shaped silk egg sacs in autumn, containing up to one hundred eggs. Spiderlings hatch in spring, undergoing multiple molts to reach maturity by late summer.
Ecological Importance
Serves as an effective regulator of ground-dwelling insect populations and acts as a vital food source for larger predators like birds and small mammals.
Conservation Status
Not evaluated by the IUCN, but populations are stable and thriving across their native and introduced ranges.
Interesting Facts
The common name 'hobo' comes from the mistaken historical belief that the spider traveled along railway lines to spread across North America.
Photography Tips
Photograph from a safe distance using macro lenses in natural light, focusing on the dorsal pattern of the abdomen and the unbanded leg structure for accurate identification.
Identified: 2026-08-05T19:37:19.641781