Do Any Dangerous Recluse Spider Species Exist In Southern California? And Why Has This Question Has Become A Source Of Controversy?

There has been much disinformation spread in California concerning the purported presence of the notorious brown recluse spider in the state. This spider species has captured the imagination of many Americans due to the necrotic bite wounds that they sometimes inflict on human skin. Many residents of southern California are under the impression that brown recluse spiders can be found within their region, but as it happens, the brown recluse is not found in any area within the state.

The persistent belief that brown recluse spiders can be found in southern California has become a source of annoyance for many entomologists, arachnologists and pest control professionals. These experts insist that this false, but widespread belief originated from poorly researched and often sensationalized news stories released to the California public by popular news outlets. This claim is not hard to believe, as a nationwide study aiming to determine brown recluse habitats had residents from all 50 states capture, preserve and send brown recluse species to researchers. Between 2000 and 2005, 600 specimens were sent in by California residents who were positive that they had captured a brown recluse. However, only one specimen turned out to be a brown recluse, and it was submitted by a former Missouri resident who accidentally transported the specimen to California from his previous midwestern home. The majority of the 600 submitted species were largely false black widows, woodlice, ground spiders and yellow sac spiders.

Brown recluse spiders have been found 17 times in California, and each one of these instances it was clear that the specimens had hitchhiked to the area via interstate shipments of various goods, most of which contained plant matter. Although the brown recluse is not native to California, 13 recluse spider species have been documented in the US, two of which are invasive. Of these 13 recluse species, two can be found in southern California. One of these species, the desert recluse, only exists in the southeastern desert region where human population levels are low or non-existent. The other species, the invasive Chilean recluse, can only be found within certain areas of Los Angeles, and specimens are rarely encountered. The Chilean recluse, however, does possess potent necrotic venom, and Los Angeles residents have been hospitalized in response to this species’ bite

Have you ever been convinced that you had found a brown recluse?