VI.8 Seasonal Occurrence of Common Western North Dakota

Several authors have compiled excellent taxonomic keys for identifying various grasshopper groups in North America: slantfaced and bandwinged adults by Otte (1981), spurthroated adults by Brooks (1958), and the identification of nymphs of the genus Melanoplus by Hanford (1946). Others have used hatching dates and developmental charts to aid in grasshopper identification. For Wyoming and Montana, excellent examples are the charts developed by Newton (1954) and the charts modi-fied for use in Colorado by Capinera (1981). Many of the identification aids are not commonly avail-able and are technical and difficult to use in a field situa-tion because of bulk and terminology. Also, the field person attempting to use such identification aids usually is a temporary summer employee with little or no back-ground in entomology. Although scientists have computer mapping technology and sophisticated methods of conducting grasshopper surveys, grasshoppers still need to be identified at each survey stop. A small, easy-to-use reference such as this one will help in the identification process. Used in combination, the seasonal occurrence chart (table 1) and the Pocket Hopper Helper can help a field person identify grasshopper species in the field. In a year with average grasshopper populations, a field person using the two aids in combination can identify an unknown grass-hopper of known life stage (instar) in western Nort