It's a myth. There are no established populations of Loxoceles reclusa in California, doctoral candidates Emma Jochim and Xavier Zahnle of the Jason Bond arachnology lab related during their 30-minute mythbusting at the Bohart Museum of Entomology open house, "Many Legged-Wonders," on Saturday, March 18. First-year doctoral student Iris Quayle of the Bond lab moderated the session.
They study with their major professor Jason Bond, the Evert and Marion Schlinger Endowed Chair in Insect Systematics, UC Davis Department of Entomology and Nematology, and associate dean, College of Agricultural and Environmental Sciences.
Jochim related that a person claiming to have been bitten by a brow recluse spider in California may have recently returned from a state where they are established or that they handled one that was shipped from that area.
That brings to mind the research of Rick Vetter of UC Riverside and his piece on "Myth of the Brown Recluse: Fact, Fear and Loathing."
"This website presents evidence for the lack of brown recluse spiders as part of the Californian spider fauna. Unfortunately, this contradicts what most Californians believe; beliefs that are born out of media-driven hyperbole and erroneous, anxiety-filled public hearsay which is further compounded by medical misdiagnoses. Although people are free to disagree, this opinion has come about after more than two decades of constant research resulting in many publications in the scientific and medical literature."
Vitter goes on to say: "Spiders are one group of arthropods that are very well known by the common person yet are terribly misunderstood; because of the rare occasion of a deleterious venom incident, almost all spiders are lumped into the category of 'squish first and ask questions later.' There are remarkably few spiders in California that are capable of causing injuries via biting. Overall, spiders are beneficial to humans in that they eat many pestiferous insects that either infest our foods (many phytophagous insects), are vectors of disease (flies, mosquitoes) or are aesthetically-challenged (cockroaches, earwigs). Unfortunately, humans have a low tolerance for spiders in their homes, either because spiders are symbols of danger, unkemptness or arachnophobia. One of the first steps one should take in dealing with these critters should be to identify them properly before blasting them with pesticide and/or getting hysterical."
Meanwhile, listen to UC Davis arachnologists:
Said one attendee: "Dr. Rick Vetter at U. C. Riverside fought the battle for the truth for decades and finally pretty much threw up his hands in defeat. He just couldn't get the media or California medical profession to stop claiming the Brown Recluse is HERE and diagnosing every little spot or open sore as a spider bite. My opinion is that people LIKE to think they were bitten by a brown recluse and wear it as a badge of honor. So much more thrilling than saying bacteria infection.”
Author - Communications specialist