Science Bulletins: Brown Widow Spiders Invade Southern California
In the last decade, brown widow spiders have made a home for themselves in parts of Southern California, a region once dominated by the more venomous black widow spider. Since the early 2000’s, the number of brown widows has increased dramatically in the Los Angeles and San Diego metropolitan areas, where they now outnumber black widows in residential locations. Competition between the native black widows and the invasive brown widows appears to have relegated black widows to agricultural and natural settings, where they still prevail. Fewer black widows could mean fewer people suffering venomous bites, as brown widows are less toxic than their bigger relatives. Black widows, however, play an important role in California ecosystems, preying on pest insects. Careful monitoring will allow scientists to determine the brown widow’s impact on the web of life in Southern California’s urban ecosystems.
This latest Bio Bulletin from the American Museum of Natural History’s Science Bulletins program is on display in the Hall of Biodiversity until September 18, 2012.