Brown Widow
See a doctorLatrodectus geometricus · also called grey widow, geometric button spider
The brown widow is an introduced species now common across the deep south and southern California, and it is displacing black widows in many urban areas. It is far more likely than a black widow to be found around a house, and the egg sacs give it away instantly.
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
- Venom is chemically similar to a black widow's but brown widows inject far less, and bites are typically mild and local. Medical attention is sensible but serious effects are uncommon.
- Size
- Body 7–13 mm. Slightly smaller and less bulky than a black widow.
- Appearance
- Mottled tan to dark grey-brown with a geometric pattern of chevrons on the upper abdomen, banded legs, and an orange or yellowish hourglass underneath rather than a red one.
- Web
- Tangle web in very exposed man-made spots — patio furniture undersides, mailboxes, wheel arches, the lip of a plant pot.
- Found in
- garden, garage, indoors
- Family
- Theridiidae
- Range
- 11 US states
How to identify a brown widow
- Egg sacs are pale and covered in spiky silk points, like a tiny sea mine. No other US spider makes these.
- Orange or yellow hourglass, not red.
- Banded legs and a mottled, patterned abdomen.
- Favours very exposed man-made surfaces — under patio chairs, inside mailboxes, in wheel arches.
How it behaves
Even more timid than black widows, and quick to drop and curl up when disturbed.
What the brown widow is confused with
One observation settles each of these.
False widows have no hourglass at all and lay smooth, round egg sacs.
House spiders have no hourglass and a smoother, rounder egg sac.