Hobo Spider
HarmlessEratigena agrestis · also called funnel weaver
The hobo spider spent two decades on the list of medically significant US spiders and was removed from it. The evidence that it causes necrotic wounds did not survive scrutiny, and the CDC no longer lists it as dangerous. It is a common Pacific Northwest house spider that runs fast and is therefore frightening, and that is all.
Quick facts
- Bite risk
- Not considered medically significant. The necrosis claim was based on limited early work that later studies did not replicate, and the CDC removed the hobo spider from its list of venomous spiders in 2017.
- Size
- Body 7–14 mm. Body about a thumbnail, legspan roughly the width of a US quarter to a half-dollar.
- Appearance
- Medium brown with a pattern of pale chevrons pointing forward along the abdomen, and — critically — plain, unbanded legs with no dark rings.
- Web
- A flat, slightly concave sheet of non-sticky silk with a funnel-shaped retreat at one edge. Built in window wells, cracks in foundations and against basement walls.
- Found in
- basement, garage, indoors, garden
- Family
- Agelenidae
- Range
- 7 US states
How to identify a hobo spider
- Plain unbanded legs. Nearly all similar-looking house spiders have dark rings on the legs — if you see banding, it is not a hobo spider.
- Flat sheet web with a funnel retreat at one corner.
- Pale chevrons pointing towards the head along the abdomen.
- Restricted to the Pacific Northwest and northern Rockies.
How it behaves
Sits at the mouth of its funnel waiting for vibrations, then dashes out. Males wander in late summer and autumn looking for mates, which is when they are found running across floors.
What the hobo spider is confused with
One observation settles each of these.
Giant house spiders are noticeably bigger with banded legs and are far more common in and around homes.
Grass spiders have two long tail-like spinnerets sticking out at the rear and bold dark stripes on the head-and-thorax.
Where it lives
If you think you were bitten
- Most suspected spider bites are not spider bites. Studies of patients presenting with a “spider bite” repeatedly find that the large majority are bacterial skin infections — frequently MRSA — which need antibiotics rather than reassurance. A spreading, painful, pus-filled sore is far more likely to be an infection than a spider.
- Wash it, ice it, and watch it. Clean the area with soap and water, apply a cold pack, and keep an eye on it.
- Get medical care if the wound spreads or darkens, if you develop cramping, sweating, fever or severe abdominal pain, or if you are confident it was a widow or a recluse.
- Bring the spider only if it is already dead and to hand. Do not go looking for it. Doctors treat symptoms, not species.
In the US, the Poison Help line is 1-800-222-1222. This site is a reference, not medical advice.