Host Plant Utilization by Grasshoppers (Orthoptera: acrididae) from a Sandhills Prairie

Abstract

Host plant use by 31 species of grasshoppers from a sandhills prairie was determined; gut analysis was used to determine diet. In the composite diet for all species, forbs constituted 37.2% of the total, grasses and sedges contributed 58%, and insects made up 4.8% of the diet. Compared to the plants available at this site, 43% of the plant species and 36% of the plant families were included in the composite diet. Although some grasshopper species did not include many host plants in their diet, most included representatives of more than one plant family. Grasshopper species were typically polyphagous with no true specialist feeders. Relatively few plant taxa constituted a large fraction of the composite diet for all grasshopper species and the relative abundance of food plants in the environment appeared to affect the overall use of food plants. Subfamily affinities are obvious. Gomphocerines have the lowest average diet breadth and are primarily grass-feeders while melanoplines feed primarily on forbs and have large average diet breadths; oedipodines are intermediate for these categories. Vegetation-dwelling species have significantly lower diet breadths than do ground-dwelling species. Results do not generally support recent theories concerning the evolution of insect herbivore feeding patterns.