JANUARY
2012

 

By
Tom Turpin
 
Professor of
Entomology
Purdue University

 

Download the audio files or subscribe to our podcast.

 

 

 

 

1-12-12

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

Little Insects on the Prairie


Almost everyone has read or heard a story that begins with, "Once upon a time." That phrase is often used to introduce a fable or a tale with its origins in bygone days. For example, "The Story of the Three Bears" begins, "Once upon a time, there was a little girl named Goldilocks."

Once upon a time in the Midwestern United States there existed a major ecosystem - the tallgrass prairie. It covered some 142 million acres from western Indiana through Illinois and Iowa to the eastern parts of Nebraska and Kansas.

The first Europeans to see the tallgrass prairie called it a treeless plain and generally did not perceive the land to be of much value. Some of the first farmers agreed, and in the words of one Illinois settler, "The land here is the worst I have seen since I left the banks of the Ohio." Indeed, Thomas Jefferson acquired most of this area for the United States as part of the Louisiana Purchase for three cents an acre.

In "Where the Sky Began: Land of the Tallgrass Prairie," author John Madson described the ecosystem as "a sunlit wilderness of grass and flowers." Today, very little of the original tallgrass prairie exists. It has been plowed and converted to crop production. We now call the area the Corn Belt.

Prairie specialists such as Madson have long debated the origin of the tallgrass prairies. Why wasn't it covered with trees, as was the case to the east, north and south? Why was it different than the shortgrass prairies to the west in the high plains? The amount of rainfall probably was the reason for the latter. But the reason for the lack of trees is less obvious. It might be soil types, the influence of glaciations, moisture evaporation rates or even prairie fires.

At one point tallgrass prairies were a distinct ecosystem of the United States, as were the steppes of Eurasia, the pampas of South America, or the veldts of Africa. When it came to wildlife, the tallgrass prairies were a transitional zone between the forests and the Western plains. For example, the prairies included bison from the West and elk, otter and beaver from forest habitats. The tallgrass prairie offered a wonderful edge habitat where forests followed creeks and rivers.

How about insects? What was the insect fauna like on the tallgrass prairie? For one thing, all those prairie flowers required insect pollinators. Native bees were everywhere on the prairie; by some estimates nearly a thousand species existed in the tallgrass prairie region.

bee
Bumble bee

Most prairie bees are what scientists call solitary bees, not social bees such as bumble bees that live in a colony. Bumble bees were certainly common on the prairie. Honey bees, on the other hand, were absent until European settlers transported them to North America.

Two of the most common types of insects associated with prairie habitats belong to the orders Hemiptera and Diptera - the true bugs and the flies. All true bugs and most flies are equipped with piercing and sucking mouths. That means they pierce their plant or animal food and suck out juice, such as sap or blood, for their use. One such bug that was common on the prairie was the chinch bug, which later became a well-known pest of wheat and corn grown on the prairie soils.

Flies were also common. Bee flies, creatures that look like bees but are flies, are often seen around prairie flowers. Biting flies, such as mosquitoes and horse and deer flies, were also found on the prairie. These flies spent their lives as immatures in the water puddles that existed throughout the prairie habitat and emerged to make life miserable for animals that lived on or venture onto the prairie during summers.

The insect associated more than any other with prairie habitats is the aptly-named grasshopper. Grasshoppers have chewing mouthparts adapted to consume the rather rough leaves of prairie plants and do well in high-temperature habitats.

But the most famous prairie grasshopper of all did not live in the tallgrass prairies. I'm referring to the famous Rocky Mountain locust, a type of migratory grasshopper, which flew from the foothills of the Rockies onto the Great Plains. This great cloud of insects destroyed all the vegetation in its path.

But no longer. The Rocky Mountain locust appears to be extinct. Both the locust and the tallgrass prairie are part of an American story that begins, "Once upon a time, there was a big prairie with some large flying grasshoppers…"

 

Writer: Tom Turpin
Editor: Olivia Maddox