DECEMBER
2011

 

By
Tom Turpin
 
Professor of
Entomology
Purdue University

 

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12-8-11

Download the audio of On Six Legs: MP3, WMV.

'Ugly is as Ugly Does' Applies to Insects


The word “ugly” is a negative term that can be used to describe appearance, behavior or even morals.  Hans Christian Anderson used the word in his tale “The Ugly Duckling.”  It is a story about inherent potential.  In this case, the ugly duckling ultimately becomes a beautiful swan.

To many people, the term is an apt expression of their feelings regarding the appearance of insects.  I haven’t done a formal survey on the subject, but in my experience people often express their feelings about insects using the words “ugly” and “gross” – especially if the encounter is up close and personal.

But wait a minute. Both “ugly” and the direct opposite “beautiful” are subjective terms.  What one person might consider beautiful is ugly to another and vice versa.  That is the reason we say such things as “Beauty is in the eye of the beholder.”

Another saying, “Ugly is as ugly does,” is said to express the idea that true beauty is found in the actions of people, not in the way they look.  Such a concept is also captured in “Beauty is only skin deep.”

So is ugly an appropriate descriptive term for the way insects appear? I suspect that we two-legged, soft-skinned humans think that the six-legged, exoskeleton-skeleton covered insects are ugly mainly because they look much different than we do.          

The physical structure of insects is an important reason these creatures are some of the most successful animals on earth.  As it turns out, ugly can be beautiful in the world of insects.  Here’s why:

Large, bulging, eyes are dominant features of some insects.  Each of such eyes can have up to 3,000 lenses, allowing an insect to see in many directions at the same time.  Such peepers might not be considered beautiful by fashion-conscious humans who squint at the world through a pair of single-lens eyes. But excellent vision is not only important to insects, it is essential. That’s because insects must constantly be on the alert for predators and their eyes are a first line of defense.

Insects also possess a pair of protrusions on their head.  These are called antennae, which make insects look somewhat otherworldly. Whether these structures resemble beads on a string, a feather duster or a saw blade, insect antennae might not be considered pretty by most people. But pretty or not, insect antennae function to pick up odors that are useful in locating food or mates.  Once again, function trumps form.

Insect bodies are also often adorned with a variety of spines and pegs. These devices are sometimes associated with the sense of touch. Sharp spines can also function to provide defense against predators.  For example, the spines on the legs of grasshoppers are powerful weapons and, in association with kicking behavior, can be used to effectively discourage an animal intent on having an insect meal. 

Then there are the mouths of insects. Insect mouthparts can vary from the chewing type that are most like human mouths because of the presence of mandibles. Cockroaches and grasshoppers have mouths of this type that are good for eating solid food such as the leaves of plants. Other insects including mosquitoes and plant bugs have piercing and sucking mouths. These insects feed on liquid food that must be extracted from the source, such as blood from a mammal or sap from a plant.  Butterflies have a coiled tube mouth good for sipping nectar from a flower.

All told, the combination of eyes, antennae, mouths and spines make insects look like – well – insects. That is a look that some humans find downright ugly. But remember that ugly is as ugly does. In this case, that ugly is associated with functions that allow insects to be successful organisms. Besides, I don’t think insects really care about whether we humans think they are ugly or not!     

 

Writer: Tom Turpin
Editor: Olivia Maddox