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Differential feeding of grasshoppers on corn and sorghums

Brunson, A.M., Painter, R.H.
Agronomy journal 1938 v.30 no.4 pp. 334-346
crossing, Zea mays, Sorghum bicolor, varieties, provenance, variety trials, Melanoplus differentialis, Melanoplus bivittatus, feeding behavior, defoliation, crop damage, varietal resistance, hybrids, inbred lines, topcrossing, Kansas
In the grasshopper outbreak of 1936 outstanding instances of differential injury among corn varieties, top crosses, and hybrids were noted. In one series of 52 hybrids, defoliation ranged from 40% to 59.8% as averages of five randomized replications. Extreme contrasts between grasshopper injury of corn and of sorghums were noted. In some cases corn in one field was eaten to the ground while sorghum in an adjacent field was practically uninjured. Although all sorghums show considerable resistance, the sorgos and kafirs were injured less than milo and milo derivatives. As a rule, the varieties and inbred lines of corn showing the greatest resistance originated in areas where grasshoppers are a natural element of the environment. It is suggested that natural selection operating in the development of adapted varieties of corn has tended to intensify resistance to grasshoppers and to other natural insect pests of the region.