Is the northern black widow dangerous?

The northern black widow is one of the few US spiders whose bite can need medical attention. Same neurotoxic venom as other widows. Painful and worth medical attention, very rarely dangerous.

How do you identify a northern black widow?

Hourglass split into two separate red bars. Row of red spots along the top of the abdomen.

Where do northern black widows live?

They are found in 22 US states, in habitats including woods, garden and woodpile.

Northern Black Widow

See a doctor

Latrodectus variolus · also called black widow

The northern black widow reaches further north than the other US widows, into New England and the upper midwest. It is more of an outdoor, woodland-edge spider than a garage spider, and its split hourglass distinguishes it at a glance from its southern relative.

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.

Bite risk: Same neurotoxic venom as other widows. Painful and worth medical attention, very rarely dangerous.
Size: Body 8–14 mm. Body about the size of a pea, legs long and fine.
Appearance: Glossy black with the hourglass split into two separate red bars rather than joined, and usually a row of red spots down the middle of the upper abdomen. Fine white or pale bands often cross the sides.
Web: Tangle web, more often in vegetation, stumps and stone walls than inside buildings.
Found in: woods, garden, woodpile
Family: Theridiidae
Range: 22 US states

How to identify a northern black widow

Hourglass split into two separate red bars.
Row of red spots along the top of the abdomen.
Glossy black with fine pale side bands.
More often in woodland edge, stumps and stone walls than in buildings.

How it behaves

Shy and web-bound. Drops from the web when disturbed.

What the northern black widow is confused with

One observation settles each of these.

Southern black widow →

The southern widow's hourglass is a single joined shape; the northern's is two separate bars.

Not sure it was a northern black widow? Identify it step by step →