About this key

There are approximately 400 known species of grasshoppers in the Western United States. During most control program activities, about 15-20% of these species are usually encountered by survey personnel. For the novice, even these commonly encountered grasshoppers can be difficult to identify. Because grasshoppers vary in their capacity for causing damage, accurately assessing the species composition in a proposed control area is critical. This knowledge allows officials to assess the threat based on the economic importance of the grasshopper species present.

There are many resources available for identifying grasshoppers. These include the traditional dichotomous keys and publications containing illustrations and relevant biological data for grasshoppers. The matrix-based (or multi-access) key presented here utilizes the vast amount of information available and offers it to the user in an easily accessible manner.

This key enables the user to identify the most common adult grasshoppers of the Western United States which pose the greatest environmental and economic threat. Nymphs were not included in this key, but will be addressed in a future version.

This key has been designed for people with varying degrees of knowledge identifying rangeland grasshoppers, from the general enthusiast to research scientist. The terminology is supported by a glossary and illustrations by Dr. Robert Pfadt from the University of Wyoming.

This key was created by the Decision Support and Pest Management Systems Laboratory of the Center for Plant Health Science and Technology.