MARCH
2002

 

By
Tom Turpin
 
Professor of
Entomology
Purdue University

 

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Check out these books by Tom Turpin:

Flies in the face of fashion

What's Buggin You Now?

 

 

 

3-28-02

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

It Isn't Easy To Be an Insect


Kermit the Frog is famous for pointing out to us all that it isn't easy to be green. But in some ways, being a green frog is easy compared to being a green insect. Or, for that matter, being any insect.

In the great scheme of nature, insects live perilous lives. Insects exhibit what biologists call an "r" strategy for survival of the species. That means that they produce many offspring so that a few survive to continue the species. Some entomologists estimate that only about 1 percent of all insects hatched live to produce eggs.

But that is enough! Every year, during the summer months we seem to be inundated with the buzzing, crawling, chomping creatures known as insects.

So what happens to the rest of the insect bunch? Many provide food for other animals. Nature is filled with animals that like to make meals of insects. Bats are almost entirely insect feeders. That is what these hairy, flying machines are up to as they zoom around the nighttime skies. They are pursuing night-flying insects, including those pesky mosquitoes, which are known to make our lives miserable.

Frogs and toads also feed on insects. Knowledgeable gardeners love to have these amphibians take up residence among the vegetables, flowers and herbs. Frogs and toads have long, sticky tongues--very functional devices for use in capturing the insects destined to be their next meal.

Some snakes also are insect eaters. However, many gardeners don't like snakes any better than they like insects. So while that little harmless garter snake might be worth its weight in gold in insects consumed, most folks would just as soon that it didn't live under the tomato plant!

All kinds of birds are insect eaters. Purple martins, barn swallows and chimney swifts all feed on flying insects. These birds, like bats, capture their insect prey while on the wing. While we would like to think that purple martins eat a lot of mosquitoes, it really isn't true. Mosquitoes are night fliers and martins are day fliers, so the two are not active at the same times. Martins certainly will consume any mosquitoes that are unfortunate enough to be on the wing during the twilight hours.

The height of flight of barn swallows has been said to be linked to the potential for rain. The adage, "swallows fly low before a rain," is related to the small insects that make up a swallow's diet. These small insects are forced to fly nearer to the ground when the barometric pressure is high, as is the case when weather fronts approach an area.

Bluebirds are also good insect eaters. So, those homeowners who place bluebird-nesting boxes on their property are also aiding in insect control in the area. It does a gardener's heart good to see mama or papa bluebird headed back to the nest with a beak full of insects!

Many insects also die because they don't have food. They either run out of food or can't find the food they need. Food is sometimes more of a problem for insects than it might appear to humans. Some insects are kind of finicky eaters. This was even recognized by the writer Lewis Carroll. In "Alice in Wonderland," Alice is talking to a gnat about the food habits of insects.

"'And what does it live on?'

'Weak tea with cream in it.'

A new difficulty came into Alice's head.

'Supposing it couldn't find any?' she asked.

'Then it would die of course.'

'But that must happen very often,' Alice remarked thoughtfully.

'It always happens,' said the Gnat."

Finding food is a problem for insects and just adds to a long list of difficulties that nature's most-successful organisms must overcome during their lifetime. However, it's unlikely that we humans will care. After all, most of us really don't like most insects, and there always seem to be plenty of the six-legged creatures around to "bug" us!

 

 

Writer: Tom Turpin
Editor: Olivia Maddox