Entomology (Study of Bugs)/CA Spiders


I was wondering if you would be interested in calling into our show this week?

We had a caller last week who claimed to have killed a "Brown Recluse" in her San Luis Obispo home.  I told her that, although I am not even close to an expert; I didn't think that species of spider was found in California...

Anyway, with Halloween on Friday and more and more spiders showing their faces this time of year, I thought that it would be entertaining and informative to have you on the show.


Hello Jay,

Thanks for the invitation, but I am not interested in calling into your show.

However, I can give you some insight into the public debate about brown recluse spiders in CA. Within the scientific community, it isnít really a debate at all. Brown recluses are not part of CA fauna. Period.

Many other spiders are often mistaken for brown recluses, including ground spiders and wolf spiders, as well as a number of others (pretty much every brown spider).

However, there are some reasons why I hesitate to definitively say that there are NO brown recluse spiders in CA. Both reasons are related to the fact that people generally want to know if they should be concerned/careful about getting bitten in CA by a potentially dangerous spider. Here are my specific reasons:

1.There are a limited number of cases in which brown recluses were actually found and identified from CA, but most of these were found in facilities that receive frequent shipments from out of state.
2.There ARE other recluse spiders in CA with venom that should be assumed to have equal potency. The most common by far is the desert recluse.

Many people in CA have had necrotic spider bites, but they were not likely caused by the actual brown recluse spider.

I hope this helps.


Entomology (Study of Bugs)

All Answers

Answers by Expert:

Ask Experts


Jessica Mellinger


I can answer questions about invertebrates native to California, including insects commonly found in homes. If you have an identification request, please attach a photo to your question.


I was involved in collection and identification of invertebrates for the United States Geological Survey, Biological Resources Division for six years. Also, I provided these same services intermittently for the UC Davis John Muir Institute of the Environment for many years. I have been a member of AllExperts.com since 2009.

Department of the Interior: United States Geological Survey, Davis Field Station; University of California, Davis Aggie Alumni Association; UC Davis Center for Neuroscience; U.S. Department of Veteran's Affairs

I have two B.A.'s from the University of California, Davis and two Associate's degrees from Sacramento City College.

Awards and Honors
Special Thanks for Achieving Results award from the Department of the Interior

©2017 About.com. All rights reserved.

[an error occurred while processing this directive]