Hobo Spider, Aggressive House Spider, Grass Spider
Tegenaria agrestis or Agelenopsis species (Hobo Spider or Grass Spider)
Agelenidae (Funnel-web weavers), Order Araneae
Physical Description
Elongated body shape with a distinct cephalothorax featuring characteristic longitudinal dark stripes and an oblong, patterned abdomen. The spider is relatively hairy with prominent spinnerets visible at the rear end of the abdomen.
Size Estimate
Body length approximately 10-18 mm with a leg span reaching up to 35-40 mm.
Coloration & Markings
Brownish coloration with a distinctive pattern of yellowish-brown markings or chevrons on the dorsal abdomen and two dark stripes running longitudinally along the cephalothorax.
Web Type
Funnel web featuring a flat sheet of silk leading into a tubular retreat where the spider waits for prey.
Eye Arrangement
Eight small, dark eyes arranged in two slightly curved, nearly parallel horizontal rows.
Leg Characteristics
Long, moderately thick legs with visible spines and faint banding, lacking specialized pad structures like heavy scopulae but adapted for rapid running across webs and ground.
Venom & Safety Information
Venom Information
Contains neurotoxic and necrotic components, though historical fears regarding severe human necrosis have been largely downplayed by modern toxicological studies.
Medical Significance
Historically considered medically significant due to fears of necrotic lesions, but current consensus views bites as causing mild to moderate localized pain, redness, and occasionally small indurations.
Safety Recommendations
Wear gloves when clearing dark cluttered spaces, shake out shoes left outdoors, and use a glass and paper to safely escort wandering individuals outside.
Habitat & Behavior
Habitat & Range
Found in temperate regions of North America and Europe, typically inhabiting dark, moist areas, grassy fields, foundations, basements, and woodpiles.
Behavior & Temperament
Timid and defensive rather than aggressive; they retreat quickly when disturbed and only bite if trapped directly against human skin.
Diet & Prey
Generalist predator feeding on crawling insects such as beetles, flies, roaches, and other spiders caught in their funnel webs.
Seasonal Activity
Most active during late summer and autumn when mature males wander extensively in search of females.
Description
A swift, ground-dwelling funnel-web builder often encountered near ground level or in home basements, known for constructing distinctive sheet webs with a hiding retreat.
Key Features
Prominent spinnerets, absence of distinct rings on the legs, characteristic herringbone or chevron patterns on the abdomen, and longitudinal stripes on the carapace.
Similar Species
Giant House Spider (Eratigena atrica) and Wolf Spiders (Lycosidae); distinguished primarily by spinneret length and precise abdominal chevron patterns.
Life Cycle
Females construct silk egg sacs in sheltered retreats during autumn, producing spiderlings that disperse via ballooning or crawling in spring; lifespan is typically 1 to 2 years.
Ecological Importance
Acts as an effective natural pest controller by reducing populations of common household and garden insect pests.
Conservation Status
Not threatened or evaluated by the IUCN; widespread and common throughout its introduced and native ranges.
Interesting Facts
Despite its specific epithet 'agrestis' meaning 'of the fields', it is frequently found around human habitations and basements.
Photography Tips
Use macro lenses with a high shutter speed or flash to freeze movement, shooting from above or the side to clearly capture the dorsal abdominal pattern and eye arrangement.
Identified: 2026-08-30T21:27:25.555867