from Chapter II of Spatial Analysis of Ecological Factors Related to Grasshopper 
Fig. 10. Spatial distribution of rangeland grasshopper outbreaks during 1975-1976, when infestation area decreased by 52.0% from the previous year (dark shading = uninfested area; blue = area infested in 1975 only; yellow = area infested in 1976 only; green = area infested both years; black = state and county borders).
