A Proctologist’s Delight: the Golden Tortoise beetle

It is possible that the habits of this minuscule insect are the most disgusting I have yet encountered. You should not feel impelled to read on. *

The Golden Tortoise Beetle adult, Charidotella sexpunctata, is a small jewel of a creature, 6mm or 0.25 inch long:

But its larva does not display to advantage. The one I am about to show you was about 2mm long, and looked like a bird dropping.

Until it moved. Beneath this unprepossessing exterior is a small fringed caterpillar-like creature with six legs, that like the adult eats the leaves of convolvulus and morning glory. It is head up in this photo:

The lumpy mass on its back is a very effective camouflage, attached to the larva by two prongs at the tail end of its abdomen, which curves up and over its back like a sunshade.

The disgusting part is what gives the carapace its name: it is called a fecal shield, and it is made of the larva’s own droppings. But how is it made?

The larva has an extendable anus, rather like an elephant’s trunk in reverse:

The droppings are extruded through this, and carefully deposited on the shield:

The shield also includes the shed skins of the larva, which goes through five skin changes en route to pupation. One old skin is clearly visible in the photo above.

Who would have thought that the union of two gilded scarabs could produce such offspring. But “Where there’s muck there’s brass”, as they say in Yorkshire.

* I have occasionally shown you other insects with similar habits, but I have never managed to get closeup details of how it all works before, so I thought I’d return to the topic. If you’ve read this far, you may well feel this was a mistake!

PS A proctologist is another name for a colorectal surgeon!