Dogbane Leaf Beetles

This is the Dogbane Leaf Beetle (Chrysochus auratus)..showy little guy.  (The Latin name hints at its golden "aura." It actually comes from the latin "aureus" which means "shining with gold") As you can see from the picture above, he is quite colorful, iridescent in fact. They aren't that common in Rutland State Park, as their primary host plant, Dogbane, isn't that common. They do still pop up from time to time and I love to find them. Their iridescence shifts from blue to green to red and orange.  The colors shift with your movements. Without getting deep, deep into the science of it all, the beetle produces these fireworks by having several layers of plates at different angles. Each layer is a different color. The result is pretty awesome.

They are pretty complicated beetles, and you might be wondering why all the craziness. Why go through all of the evolutionary effort? Well, first of all, being beautiful seems to be one of the purposes of this flashy armor. That does get us into some philosophical areas, but it would be sad not to see the beauty all around us and simply acknowledge that it is there to be admired. The beetles also enjoy the coloring in the same way that birds use their coloring; to attract mates.

The beetles bright coloring might also hint at their poisonous nature. The Dogbane plant is toxic. It's

right there in the name, "Dog Bane." The plant is similar to the milkweed, which is also toxic. When livestock ingest Dogbane it can cause sickness, and in smaller animals... dogs... it has been known to lead to death. I am still wondering why dogs go out and eat grass. Chaucer certainly partakes in a little grazing while we are out walking, then he also partakes in a little heaving afterward. Why? I have no clue.  These beetles seem to have no problem with it though. I haven't seen them eating Dogbane, but I have watched them eating milkweed. The white "milk" that gushes from milkweed, and dogbane, is the poisonous stuff. To avoid getting stuck in it, or ingesting it, the Dogbane Leafbeetle cuts a vein of the leaf further up the leaf. This is similar to monarch caterpillars but less aggressive, as the monarch caterpillar actually severs an artery at the base of the leaf before eats the whole leaf. The beetle just cuts a bit above where its going to eat and then eats at its leisure. I have observed these guys on Queen Anne's Lace (another poisonous plant) many times (as is the one on the right), but have never seen them eating it.

These are truly beautiful little beetles, and although they do selfishly kill the Dogbane plant without any sort of symbiosis evident (their larvae eat it by the roots) it is a poisonous plant, and harmful to livestock, so they are on our side right? For simply their beauty alone, I am always happy to find them. I am reminded why Salvador Dali, in all his eccentricity, was drawn to wear beetles on his lapel. They are beautiful.