Summary
Once listed by the CDC as a spider of medical concern, the hobo spider was formally removed from that list in 2017 after subsequent research failed to replicate the necrotic effects originally attributed to its bite.
Quick answers
- Is Hobo Spider dangerous to humans?
- No. Current evidence does not link hobo spider bites to serious medical outcomes in healthy adults.
- How big is an adult hobo spider?
- Adult female body length is 11–15 mm; males are 8–11 mm. Leg span reaches 27–45 mm.
- Where does Hobo Spider live?
- Ground-level structures: cracks in foundations, woodpiles, basements, crawlspaces. Builds funnel webs with the retreat opening at the back. Established U.S. populations occur in 7 states.
- What does Hobo Spider eat and when is it active?
- Insects that fall onto the funnel web sheet. Nocturnal. Males wander aggressively in late summer searching for mates - the source of most encounters with humans.
Identification
- Body 11–15 mm with long legs (no banding)
- Brown overall with subtle herringbone or chevron pattern on the abdomen
- Two long, distinctly extended spinnerets visible from above
- Builds a sheet web with a funnel retreat at one end (genus-typical)
- Lacks the dark bands on legs seen in the closely related giant house spider
Morphometrics
| Measurement | Female | Male |
|---|---|---|
| Body length | 11–15 mm | 8–11 mm |
| Leg span | 27–45 mm | - |
| Lifespan | 1–2 years | - |
| Trait | Value |
|---|---|
| Web type | Horizontal funnel web with a tubular retreat at the back - built in low corners, woodpiles, and basement window wells. |
| Eye arrangement | Eight eyes in two roughly equal rows of four. |
| Eggs per sac | 100–400 |
| Egg sacs per year | 1–4 |
Geographic range
Native range: Native to Europe; introduced to the Pacific Northwest in the 1930s, now established from British Columbia south to Oregon and east into the Rockies.
U.S. states with established populations: Colorado, Idaho, Montana, Oregon, Utah, Washington, Wyoming.
State pages covering Hobo Spider
Habitat & behavior
Habitat: Ground-level structures: cracks in foundations, woodpiles, basements, crawlspaces. Builds funnel webs with the retreat opening at the back.
Activity: Nocturnal. Males wander aggressively in late summer searching for mates - the source of most encounters with humans.
Diet: Insects that fall onto the funnel web sheet.
Venom & medical significance
| Venom property | Value |
|---|---|
| Type | Not established as medically significant |
| LD₅₀ | Not established |
| Note | CDC removed the hobo spider from its venomous spider list in 2017. Current consensus is that the species is not a significant cause of necrotic lesions. |
Bite symptoms & first aid
Symptoms
- Bites are rare and most cause only minor local irritation
- Earlier reports of necrotic lesions have not been replicated in controlled studies
Commonly confused with
- Giant house spider
- Barn funnel weaver
- Wolf spider
- Grass spider
Key facts
Sources
- [1]Venomous Spiders - Workplace Safety and Health Topics - CDC / NIOSH. Accessed 2026-06-14.
- [2]Vetter et al., The hobo spider has been wrongly accused (Toxicon) - Toxicon, 2014. Accessed 2026-06-14.