A little piece on spiders in the UC Master Gardener column of the Contra Cost Times last month caused quite a stir. In answering a question about brown recluse spiders, the writer said: "Brown recluse spiders are not found in California, except in the far southern eastern desert regions, and it is highly unlikely that you have a population in your backyard. As of now, there has not been one confirmed brown recluse spider bite in the state."
The UC Integrated Pest Management Program reports similar information on its Web site: "There are no populations of the brown recluse Loxosceles reclusa, in the state and fewer than 10 verified specimens have been collected over several decades in California. Yet people frequently relate stories in which they or someone they know was supposedly bitten by a brown recluse in California."
This past weekend, the Contra Costa Times reported that the assertion about brown recluse spiders sparked heated debate. Many residents who responded said they were sure the brown recluse spider is in the Bay Area. To find out for certain, UC Riverside entomologist Richard Vetter offered to identify any spider suspected of being a brown recluse.
Residents are invited to carefully capture spiders they think may be brown recluses and deliver them to the Contra Costa County UC Cooperative Extension office.
At the risk of giving readers the heebie-jeebies, here are some things that distinguish the poisonous brown recluse from harmless garden spiders:
- Six eyes arranged in pairs, with one pair in front and a pair on either side. (Most spiders have eight eyes.)
- A dark violin shape on the cephalothorax (the portion of the body to which the legs attach).
- Uniformly light-colored legs, no stripes, no bands.
- Uniformly colored abdomen which can vary from cream to dark brown depending on what it has eaten.
