The brown widow spider, Latrodectus geometricus, is related to the medically important black widow spider. It’s not nearly as toxic, however, as its better-known relative. A native to either Africa (most likely) or South America (less likely), the brown widow has, for many decades, been restricted to Florida. In the first part of the 21st century, however, they expanded their range to include coastal areas from South Carolina to Texas and urban southern California and Utah.
Brown Widow | Latrodectus geometricus
The brown widow is bedecked in tan and brown mottled coloration with an orange hourglass on the ventral portion of its abdomen. A series of brown and white spots along the abdomen runs on its top with three diagonal lines on the sides. One of the most identifiable aspects of brown widows is the egg sac, which has small silk spines poking out of its surface. No other urban North American spider makes an egg sac like the brown widow’s, making it one of the few examples where identification can be confirmed without seeing the actual spider.
In most cases, bites from a brown widow don’t produce extreme manifestation of envenomation similar to black widow bites. The most typical reactions caused by verified brown widow bites are pain when it happens, as well as a small red mark. There has, however, been one report of a verified bite that required hospitalization. Because this spider has the word widow as part of its name, it will generate concern from homeowners even though it is not as dangerous as a black widow.
These spiders are most often found in places that offer some harborage like under wood or potted plants, in debris, in pipes of fences and bicycle racks. Control would be best by spraying upwards under overhangs and in holes.