Brown widow spiders are fairly new arrivals in California. For creatures that are supposed to be reclusive, I've been seeing quite a few. I first became aware of them at the end of August when cleaning my classroom. I saw some round, white, spiky egg sacs attached to the window and a coworker told me they were from brown widows. Never having heard about brown widows, I looked them up and she was right. I wish I had taken pictures. Now I found a large brown widow that lives behind a leaf on my back wall. There are babies as well. It's a speedy spider and I have not been able to get a good picture of the orange marking on the belly, but it's there.
You can just about see the orange marking through the blurriness.