L.A. Spider Survey Finds a Tropical Brown Widow

A tropical brown widow spider -- twice as poisonous as the more common black widow -- has been discovered in Los Angeles as part of the ongoing spider survey by the Natural History Museum of Los Angeles County. Researchers believe it probably arrived on imported plants, flowers, food or furniture.

The spider was discovered by a fourth-grade student from Van Deene Elementary School in Torrance while the student was on a field trip run by the museum. “The spider was inside a rolled-up leaf of a Bird of Paradise plant on the school grounds,” said Beth Nordeen, a museum outreach educator.

The brown widow, Lactrodectus geometricus, can grow up to 1 1/2 inches long and has an orange-to-yellow hourglass design on its underside, as opposed to the familiar red hourglass design of the black widow. Its venom is more than 15 times as toxic as that of the common rattlesnake, but it injects a much smaller amount when it bites, so bites are not normally fatal.

Brown widows usually will not attack if they are not bothered or made to feel threatened, said entomologist Brian Brown of the museum.

The spider, along with its egg sac containing as many as 100 offspring, is on display in the museum’s Insect Zoo.