- 1Grass nutrient levels differed considerably between the grass species and with time.
- 2Most species of leafhopper (Homoptera, Auchenorrhyncha) were present on all the grasses sampled but each grass had a different dominant leaf-hopper fauna.
- 3The leafhopper—plant association varied depending on the leafhopper species. Species that were strongly associated with one host were rare. Other more oligophagous species were associated with a particular nitrogen level in the grass. These species were found on grasses that had nitrogen concentrations within a narrow range. As the plant nitrogen levels altered (associated with flowering, seed setting, and senescence) leafhoppers switched onto other food plants that had a suitable nitrogen level. An intermediate group of leafhoppers showed little specificity and little association with plant nitrogen levels.