7. Arthropod Pests of Wheat

By Gary Hein, Gerry Michels, & Phil Sloderbeck

Only a few arthropod species in Great Plains wheat can be considered serious pests. The Russian wheat aphid is sporadic in occurrence through most of the Great Plains, except in Colorado where growers must deal with it almost on a yearly basis. The greenbug can be a serious pest across the Great Plains, but its greatest impact is in the southern plains (Texas, Oklahoma, and southern Kansas), and it is only a sporadic problem further north. A few other pests can be found in most years, but serious infestations will only occur in limited areas. For example, wheat curl mite, which transmits wheat streak mosaic and High Plains viruses, is consistently present in the region but only becomes serious when and where conditions are favorable for its survival through the summer. Also, in most years the army cutworm will seriously impact wheat somewhere in the Great Plain, but the areas of serious infestations tend to move from year to year.

Some pests appear to be of increasing concern. The Hessian fly has increased its presence in recent years in some areas of Oklahoma, Kansas, and Nebraska. Cereal aphids, which were not thought to overwinter north of central Kansas, have been able to overwinter much further north, and the wheat stem sawfly has increased its presence in no-till areas of the high plains of Wyoming and Nebraska.

The impact of a changing climate and changes in production practices, particularly the warmer falls and winters and the increased use of no-till farming, have and will continue to impact pest species. It is likely that the spectrum of pests will change if climatic conditions and farming practices continue to change. The development of effective integrated pest management programs to manage pests will become increasingly complex and will rely on increased knowledge of pest biology and their relationships with host plants.