Southern Black Widow
See a doctorLatrodectus mactans · also called black widow, shoe-button spider
The southern black widow is the classic widow of the eastern and southern United States. Everything about identifying it comes down to two things: the varnished black gloss, and the red hourglass on the belly of the spider hanging upside down in a messy web.
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.
Quick facts
- Bite risk
- Neurotoxic venom causing painful cramping and systemic symptoms. Seek medical care. Not a cause of necrotic wounds — that is the recluse, and even then rarely.
- Size
- Body 8–16 mm. Female's body about the size of a large pea, with a distinctly round, glossy abdomen.
- Appearance
- Glossy black with a complete red hourglass underneath, often with a single red spot near the tip of the abdomen on top. Males are small, brown and striped.
- Web
- Irregular tangle web in sheltered low places — under steps, in crawl spaces, inside meter boxes and outbuildings.
- Found in
- garden, garage, woodpile, basement
- Family
- Theridiidae
- Range
- 23 US states
How to identify a southern black widow
- Complete red hourglass on the underside.
- Glossy, wet-looking jet-black body.
- Round, bulbous abdomen and long thin legs.
- Messy tangle web in a dark sheltered spot near ground level.
How it behaves
Retreats rather than confronts. Almost all bites are defensive and happen when the spider is squashed against skin.
What the southern black widow is confused with
One observation settles each of these.
The northern widow's hourglass is split into two separate red bars, and it usually has a row of red spots down the top of the abdomen.
Brown widows are mottled tan with an orange hourglass, and their egg sacs are covered in spiky points.