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Green leaf beetles (Trirhabda flavolimbata) at the Carpinteria Salt Marsh

I mentioned previously that I’m a volunteer docent at the Carpinteria salt marsh. I started off being mostly into birds, but in the spring of 2009 I started obsessing about bugs, and it was these beetles that started that. I was looking for invertebrates to photograph for Circus of the Spineless, when I discovered that there were large numbers of shiny green “caterpillars” (I thought) feeding on the coyote brush (Baccharis pilularis) at the marsh. I estimated that there were more than 500 of them in a single medium-sized bush.

It turns out they were actually beetle larvae. Over the next several weeks I watched as they turned into adult beetles and kept munching. By the end of the outbreak, in late May, much of the coyote brush along Ash Avenue had been completely defoliated. The first two shots above are from that 2009 outbreak; they show the larvae (left) and an adult beetle (right).

By the next year the coyote brush had bounced back. There were only a few leaf beetles at the marsh each of the next three springs, but this year they’re back in a big way. Once again, a lot of the marsh shrubbery has been eaten down to bare twigs.

I was out there yesterday and today gathering data as part of a citizen science project that I’ll write up in another post, and while I was there I took some photos.

The second row above shows the effect the beetles have on the coyote brush. On the left is a plant that still has leaves (and beetles). On the right is one that’s already been eaten.

Finally, there’s a shot I took with the macro lens attachment I bought recently for my iPhone. It’s just a little dingus that slips over the end of the phone. I’m pretty impressed with how well it works, though I need to work on my focus skills. There isn’t much depth of field to work with.

Isn’t that beetle adorable?

I tried taking some video, too, which I’m in the process of uploading to YouTube. I’ll post a link to that when it’s ready, so you can see beetles in motion. (Update: As promised: shaky beetle video.)