Posts Tagged ‘leaf beetle’

From poop to gold

April 3, 2010
Golden Tortoise Beetle © Beatriz Moisset. 2009

Golden Tortoise Beetle
© Beatriz Moisset. 2009

Somewhere around there, there is a little beetle with a sweet tooth for sweet potato leaves. It goes about munching leaves day after day and growing very fast, but if you saw it you would never guess that it is a beetle. Like all other beetles it starts its life as a wormy looking thing called a larva or a grub. Butterflies do that to, they look very different when they are babies and go through a dramatic change before they emerge as winged adult insects.

It is a tiny grub, no bigger than your baby sister’s pinky’s fingernail. It is all wrinkly and has powerful jaws for chewing the tasty leaves. This grub has a very peculiar habit, each time that it poops, instead of dropping its waste and moving on, it places it on its back along with the remnants of skin that it sheds periodically. To do that it has this curious thing with several hooks looking like a coat rack sticking out of its back. In other words it carries its old skin, its poop as well as some little pieces of debris held on high like an umbrella over its back.

Golden Tortoise Beetle larva carrying its feces  © Beatriz Moisset. 2009

Golden Tortoise Beetle larva carrying its feces
© Beatriz Moisset. 2009

It diligently takes care of this nasty umbrella; each time that it needs to relieve itself it stretches a long and flexible hose from its back end and skillfully spreads the material on top of the existing messy thing. When it dries up it turns black and rather disgusting. You wouldn’t know that there is a living creature underneath.

Why would it have such a filthy habit? Didn’t its mother teach it any better? Well, it turns out that it has very good reasons for doing this. The poop beetle is a very tasty morsel that any passing bird would gobble up with relish. But birds don’t feel tempted by such an ugly sight, so they fail to see the snack underneath. That is how the little grub can go on munching away unmolested hiding in plain sight.

Sweet potato plants look similar to morning glories and for a very good reason, they are related plants. The poop beetle grub likes morning glories just as much as it likes sweet potatoes; so if there are some morning glories in your neighborhood you may be lucky and get to see one of them. Look at the leaves and if you see holes here and there they may be on the right track for finding a poop beetle grub. Remember that it is very little and that it looks like nothing but a piece of black debris. Also, it may have already left the plant and moved on somewhere else. However, if you see one it is possible that it will wave its umbrella once or twice if startled, hoping to scare away the observer.

After it has been eating almost non-stop for a couple of weeks it will reach its full size and now it will be ready to turn into its adult shape as a beetle, that looks vaguely like a tiny ladybug. This is not an easy transformation; a lot has to take place to make all the changes, grow legs, antennae, wings. So it needs peace and quiet while doing all this remodeling. It may move to another plant nearby, not necessarily a morning glory, sweet potato or related plant, but something altogether different such as goldenrod.

It prefers to anchor itself on the underside of a leaf and once there it sheds its skin one more time and may or may not drop the umbrella along with it. Now it looks like an armored little tank called a pupa. The pupa goes to sleep for just about a week, after which time it wakes up ready to start a new life. Not much happens on the outside, but huge changes are taking place inside.

When it is time to come out of this shell the poop grub has one final trick up its sleeve. The front part of the pupal case opens up on two hinges; all what it takes is a little push and the front opens like a double door and the brand new beetle emerges like a car getting out of a garage, a very tight parking space if I may say so.

The gorgeous little creature that emerges bears no resemblance to the larva or the pupa. It is like a tiny turtle; its shell is glossy pink with a hint of gold. And then, depending on how the light hits it, it looks gold with a hint of pink. It may remind you of nail polish; pale at first, becoming a little richer and darker in a few hours. It usually sports six black dots; its edge is flared and transparent. The freshly emerged new beetle waves two delicate antennae exploring the new world. It may take a while before it tries its new wings and take to the air. Now it can proudly bear the name for which it is best known, the golden tortoise beetle.

One wonders how this little piece of gold and pink emerged from such ugly, dirty grub. Keep checking those morning glories, you may be rewarded by its sight, just remember, it is no bigger than a tiny gob of pink nail polish.

Learn more here

Beginners Guide to Flower Visitors

© Beatriz Moisset. 2009

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