Figure 1a and 1b. Corn field showing leaf defoliation by grasshoppers and individual corn stalk cut off at the base. (Photos by Jeff Bradshaw)

August 20, 2010

Grasshoppers have dominated the concerns of crop producers and home owners in western Nebraska throughout the summer. About 100 species of grasshoppers can be found in Nebraska, each with their own unique biology and environmental preferences. This year, we have had two noticeable peaks in grasshopper abundance during the spring (dominated by our rangeland species) and at least one more as summer progressed (dominated by our cropland species).

The first peak was reduced in western Nebraska due, in part, to the cool, wet weather; however, the remaining populations flourished.

In some regions, large numbers of two-lined grasshoppers were observed and as the season progressed, the abundance of differential and red-legged grasshoppers increased. Most of these are now winged adults. In fact, some producers have reported seeing swarms of grasshoppers flying ahead of irrigation pivot lines as they move. Always in the background, at a slightly lower abundance, are numerous other grasshopper species.

Some crops, such as corn planted adjacent to grasslands, have suffered major damage and in some cases, the damage has been quite bizarre. A recent visit to a corn field in Scotts Bluff County revealed about 30-40 rows of defoliated corn. The silks were chewed off prior to pollen shed (thus preventing grain fill) and the outermost rows had many stalks clipped by grasshoppers (Figure 1).

As the grasslands have continued to desiccate, grasshoppers have affected a greater diversity of crops. For example, sunflowers, particularly along field borders, have shown signs of grasshoppers feeding on the developing seeds in the head (Figure 2). Home owners have reported grasshoppers defoliating their gardens, removing paint from dwellings (Figure 3), and even defoliating their blue spruce.

It has indeed been an outbreak year for grasshoppers in western Nebraska, and with wheat planting around the corner our crops are still very much at risk. What grasshoppers will unleash on us next year is still very uncertain; however, a shorter fall could certainly reduce their numbers next year.

Jeff Bradshaw
Extension Entomologist, Panhandle REC, Scottsbluff

More Information

If you want to learn more about grasshoppers found in Nebraska and their management, check out these Extension publications:

• Grasshoppers of Nebraska, available online or in print from your local Extension office.
• A Guide to Grasshopper Control in Cropland (G1627)
• A Guide to Grasshopper Control in Yards and Gardens (G1633)
• A Guide to Grasshopper Control on Rangeland (G1630)

Grasshopper identification guides are also available on the Extension Publications website.