MARCH
2014

 

By
Tom Turpin
 
Professor of
Entomology
Purdue University

 

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Flies in the face of fashion

What's Buggin You Now?

 

 

 

03-13-14

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Insect Peekaboo


moth
The "eyes" on the io Moth's underwings scare away would-be predators.

Remember that old game of peekaboo? It's a game played between an adult and a baby. It works this way. The adult covers up an object and then uncovers it in the presence of the little child and says "peekaboo!" Sometimes the object is an adult's face covered with his or her hands.

According to developmental psychologists, peekaboo plays an important role in the psychological development of children. The child playing the game is learning an important concept. It is object permanence - the idea that things exist even when they cannot be seen.

It is probably safe to say that most of us don't think about highfalutin psychological concepts when we play peekaboo with kids. We are just playing the game to keep the little rug rats occupied.

Insects also play a version of the peekaboo game. But for insects, peekaboo is not a matter of psychological development. It is a matter of life or death.

One of the risks of being an insect is that the world is full of insect-eating animals. Such animals survive by capturing insects to fulfill their nutritional needs. That is good for the insect-eater but is a real downer for the insect that becomes the meal.

So insects, as a matter of survival, have developed ways to avoid becoming meals for other animals. They fly, they hide and they taste bad. And some insect species employ what scientists call protective coloration. That means their color patterns allow them to send a message to a predator. Messages such as, "I can hurt you because you think I am a bee." Or, "I am not something you want to eat because I look like bird manure." Or "My bright color means I taste bad."

One of the most interesting methods that insects use for survival is based on their ability to change the way they appear. It is very much like a game of peekaboo. This is a type of flash coloration that could be described as, "Now you don't see me, now you do!"

Here's how insect peekaboo works. The insect is colored so that when it is at rest, it blends into the surroundings: for instance, a green katydid on the leaves of a tree, a brown grasshopper on a dusty road or a gray moth on tree bark. Such insects gain a measure of protection because predators may not notice them.

moth
The color of the io moth blends in with the bark of a tree.

However, peekaboo insects have a second line of defense. If they are discovered, they respond by presenting a totally different color pattern to the prying eyes. One of the most impressive is the io moth. This moth is dull colored so that it blends in on the bark of a tree. When discovered, it exposes its back pair of wings, sometimes called the underwings of a moth, which are marked with eyes. These eyes resemble the eyes of a hawk or owl - birds of prey - that might make a meal of smaller birds. When the small bird spies such eyes, it decides to take evasive action itself; the moth has gained protection by playing a game of peekaboo.

The dusty-road grasshopper is another insect adept at the game of peekaboo. In this case, the grasshopper sits on the roadway and, because of a similar color, blends in nicely. When disturbed, the grasshopper takes flight, and its back wings, marked with bright yellow, orange or red, become visible. The predator will follow the flight of the grasshopper by keying in on the bright colors. When the grasshopper lands, the bright backwings are covered up, and the grasshopper again blends into the environment.

Some grasshoppers also add sound to the "look-at-me" charade associated with flight. These grasshoppers make a clicking sound in flight. So the sound and color both serve to attract attention to the flight of the hopper. Now you see me and hear me, now you don't!

For both dusty-road grasshoppers and humans, the game of peekaboo involves sight and sound. The major difference is that for the grasshoppers the game is a matter of survival. For humans, it is just a step in psychological development and something to do when the baby gets restless!


 

Writer: Tom Turpin
Editor: Olivia Maddox