The Gold Bug

Golden Tortoise BeetleCharidotella sexpunctata bicolor

Just after I finished building the cairn yesterday, I wanted to do some watering of some things that were looking a little wilted. As I stood there with the hose, the water happened to flip over a leaf of something I planted from seed but forgot to label (that means I have no idea what it is yet because it hasn't bloomed). There, glinting in the sun, attached to the underneath side of a leaf, was a piece of gold.

What?

This required closer inspection, so I turned off the water and crouched down. Wow! A gold bug! This immediately made me think of Edgar Allan Poe's story, "The Gold Bug." I'm sure I've read the story, because I used to like Poe when I was in high school, but I can't remember what the story was about.I happened to have the camera out there, because I'd just taken a picture of the newly constructed cairn, so I grabbed it from the tree branch where I'd hung it, and got in for a tight shot. I was able to get three close-ups before it flew off.

When I brought the photos up on the screen, I immediately noticed the outer shell on The Gold Bug was clear! It didn't take much googling before I was able to identify it as a Golden Tortoise Beetle. It's a bit smaller than a ladybug, and it shines like a piece of fine gold jewelry. Except when it doesn't.

The gold color is caused by light reflecting on a thin layer of moisture between the outer shell, which resembles a tortoise's (hence the name), and its body. It has the ability to voluntarily compress this liquid, thereby changing its color to a muddy, spotty reddish color. It does this when it's stressed and it's also the color it becomes when it dies.

It feeds exclusively on the leaves of plants in the Convolvulaceae family, which includes sweet potatoes, bindweed, morning glories and Convolvulus. Hmmmm ... maybe it was the Convolvulus seeds that I planted there ...