Cultivar Resistance to Grasshoppers in Temperate Cereal Crops and Grasses: A Review

Abstract

Grasshoppers are the most important insect pests of small grain crops (Hehn and Grafius 1949, Olfert 1986), and of rangeland plants in the United States and Canada (Hewitt 1977). At times, grasshoppers are serious pests of other crops (Sanderson 1939, Pfadt 1949, Barnes 1955). The historical and continuing importance of grasshoppers in the plains region of North America is evident from the many references to their depradations in Pfadt and Hardy (1987) and Riegert (1980). Fluctuations in grasshopper populations lead to periodic outbreaks of sufficient severity to cause millions of dollars in damage in Canada and similar amounts expended on chemical control measures (Gage and Mukerji 1978). The need to control grasshoppers has been a constant feature of crop production in the prairie region. Initially, this was achieved using bran or sawdust baits to which poisons, frequently arsenic, were added (Riegert 1980). In the period from the early 1940's until the present, a succession of pesticides of different classes, generally increasing in specificity and efficacy, were used to control grasshoppers. However, recent concerns over pesticide use and their cost have stimulated a broad interest in