Most of the beetles looked like this (see next image). It might be a Spotted Cucumber Beetle, but I don't have much experience identifying this type of beetle, so please let me know if you are familiar with this species.
When I started looking more closely, I realized there were other species involved. There were quite a few ladybugs, or ladybird beetles (see below for one example). And a smaller beetle with mottled orange and brown markings (also in the image below).
And a wonderful weevil:
And there were true bugs, too! Check out this intense metallic green bug:
And a bright orange stink bug (upside down, with wings open):
And a treehopper with a rounded red horn (placed on a Bull Kelp float for a photo)!
And then I was more than surprised to see a backswimmer washed ashore! They're normally in freshwater ponds, but they can fly, so it must have been caught offshore and then washed in by the waves.
And then this water strider, too!
Okay, I think you're getting the idea that there were a lot of insects washed up on the beach today. I'm just showing a few of them, but there were also bees, wasps, flies, butterflies, moths, and more.
I'm not quite sure what happened to all of these animals. Perhaps they were dispersing during the warm weather, drifted too far offshore, then got caught in the strong winds during the past couple of days, blown onto the surface of the ocean and then washed up onto the beach. Do you have other ideas?