Hobo Spider, Aggressive House Spider
Tegenaria agrestis
Agelenidae (Funnel-Weavers), Order Araneae. Key family characteristics include long spinnerets and a distinctive funnel-shaped web.
Physical Description
Elongated body with a light brown cephalothorax featuring darker brown longitudinal stripes. The abdomen is oval, covered in a complex, chevron-like or mottled pattern with alternating yellowish-brown and dark brown markings.
Size Estimate
Body length typically ranges from 11 to 18 millimeters for females, with a leg span reaching up to 40 millimeters. This specimen appears to be an adult.
Coloration & Markings
Dull brown coloration overall. The cephalothorax features indistinct dark longitudinal stripes, while the dorsal abdomen displays a distinct pattern of chevron-like markings pointing forward.
Web Type
Builds a characteristic non-sticky sheet web that funnels into a tubular retreat where the spider waits for prey, typically constructed near ground level in dark, undisturbed areas.
Eye Arrangement
Eight eyes of roughly equal size arranged in two nearly straight horizontal rows of four across the front of the cephalothorax.
Leg Characteristics
Long, relatively robust legs that are uniformly brown without distinct banding, covered in fine hairs and prominent spines.
Venom & Safety Information
Venom Information
Contains a necrotic venom, though the severity of its medical impact on humans remains a subject of scientific debate and historical overstatement.
Medical Significance
Historically feared for causing necrotic lesions, modern toxicology suggests bites result in temporary localized pain, redness, and occasionally mild localized tissue irritation similar to a bee sting.
Safety Recommendations
Wear gloves when moving firewood or cleaning out dark storage areas, seal home entry points, and gently relocate indoor spiders using a cup and card.
Habitat & Behavior
Habitat & Range
Native to Europe and Central Asia, introduced to the Pacific Northwest of North America. Prefers dark, moist environments, often found in woodpiles, tall grass, foundations, and crawl spaces.
Behavior & Temperament
Reclusive and defensive rather than aggressive. They typically run rapidly when disturbed and only bite if trapped directly against the skin.
Diet & Prey
Generalist nocturnal hunter feeding primarily on crawling insects such as beetles, roaches, flies, and other spiders.
Seasonal Activity
Most active during late summer and autumn, particularly males wandering in search of mates.
Description
The Hobo Spider is a classic funnel-weaver adapted to human structures as well as natural fields. With its mottled brown pattern and speedy gait, it is a master of catching unsuspecting insects in its sheet-like webs.
Key Features
Uniformly brown legs lacking dark bands, distinct chevron patterns on the abdomen, and construction of a horizontal funnel web.
Similar Species
Giant House Spider (Eratigena duress) and Common House Spider (Parasteatoda tepidariorum). Distinguish by examining leg banding and abdominal markings.
Life Cycle
Females produce flat, disc-shaped egg sacs in the fall, containing dozens of eggs that overwinter. Spiderlings hatch in spring, maturing over a two-year lifespan.
Ecological Importance
Acts as an effective natural pest controller by reducing populations of crawling household and garden insects.
Conservation Status
Not evaluated by the IUCN, highly secure and abundant in its introduced and native ranges.
Interesting Facts
Despite its specific epithet 'agrestis' meaning 'rural', it frequently populates urban basements and foundations, leading to its common English name.
Photography Tips
Use a macro lens in well-lit conditions. Capture dorsal views to clearly show the abdominal chevron pattern and the lack of banding on the legs.
Identified: 2026-08-15T16:05:26.717177