Chinch Bug: How a Tiny Insect Helped the Rise of Dairy in Wisconsin

It was over 170 years ago that Wisconsin was granted statehood.  While much has changed over the decades, some things haven’t—like the omnipresence of agriculture.  It’s hard not to notice agriculture in Wisconsin, be it crop fields, orchards and vineyards, or our famous dairy farms dotting the landscape.  To many, Wisconsin is practically synonymous with dairy, and America’s Dairyland is even enshrined on our license plates.  While Wisconsinites may take our dairy prominence for granted, it turns out we weren’t always the Dairy State—at one point in history, you might have even called us the Wheat State.

It’s easy to understand why Wisconsin has a long history of agriculture.  The region received an influx of rich soil with the last ice age which allowed us to become a top wheat producer in the early days of statehood.  To early farmers in Wisconsin, wheat was a profitable crop in high demand.  For a period in the 1800’s, Milwaukee was even the busiest wheat shipping port in the entire world1.  Fast forward to today and Wisconsin is best known for its dairy production, while states like Kansas, Nebraska, and the Dakotas are known for their bountiful grains.

Quote from J.G. Thompson’s The Rise and Decline of the Wheat Growing Industry in Wisconsin2

It was the mid-to-late 1800’s when the course of Wisconsin’s history was forever altered by a number of factors.  Fluctuating wheat prices and overworked soil might have been the primary drivers, but dry weather and a tiny insect also pulled on the reins of history.  Just as mosquitoes can thrive after heavy rains, other insects thrive under hot, dry conditions.  Droughts of the 1860s, 70s, and 80s set the stage for biblical outbreaks of some of these insects.  Farther to the west, fields in the Great Plains fell victim to swarms of Rocky Mountain locusts so massive that they darkened the sky for thousands of square miles.

Closer to home, the pest delivering a coup de grâce to wheat fields was the humble chinch bug, which thrived under the dry conditions at the time.  Chinch bugs aren’t much to write home about: at roughly an eighth of an inch long, most folks wouldn’t take the time to examine these tiny, black and white insects.  It was by their sheer abundance that these creatures decimated Wisconsin’s wheat fields in the 1800’s.  Using needle-like mouthparts, these insects sucked the life out of wheat plants, leaving behind wilted, yellowed stems.

The chinch bug (Blissus leucopterus). Photo Credit: David Shetlar, The Ohio State University, Bugwood.org.

When a pest outbreak occurs in a given year, a farmer might chalk it up to bad luck, bad weather, or other factors and hope things improve the next season.  With falling wheat prices and chinch bugs regularly devastating wheat crops in the late 1800’s, Wisconsin wheat farmers realized that their efforts yielded little profit.  Without an effective way to prevent the ravages of the chinch bugs, attentions shifted to more fruitful possibilities.

The first comprehensive report on the biology and habits of the chinch bug.

Understanding the biology of the chinch bug was crucial to discovering the limitations of that insect’s destruction.  It turns out that chinch bugs are picky eaters with a taste for grasses—wheat, corn, and similar.  Unrelated plants, including forage crops like alfalfa, weren’t affected by these insects and could be grown to feed livestock at the very time that the dairy industry was budding in Wisconsin.  Decades later our dairy prominence is featured on our license plates.  

When enjoying those Wisconsin cheese curds, ice cream, and other dairy treats during national dairy month, chances are you probably wouldn’t have thought about insects—but now you know how the tiny chinch bug helped make dairy a BIG deal in Wisconsin.


1Harbor and Marine Interests. History of Milwaukee City and County Vol I. Ed. W.G. Bruce. 1922. Print.

2J.G. Thompson. The Rise and Decline of the Wheat Growing Industry in Wisconsin. Bulletin of the University of Wisconsin No. 292. Economic and Political Science Series. Volume V(3): 295-544. 1909. Print.