Species richness of grassland Heteroptera at Royston, Hertfordshire, was low and few differences between treatments were observed. Significantly more plant bugs overwintered in the coarse grassland than in the fine, with consistent, significant differences between treatments for Notostira elongata and Nabis ferus. Auchenorhyncha were more abundant on the coarse grassland in 1974, but on the fine grassland in 1975. Species richness, equitability, and especially diversity, were higher on the coarse sward. The fauna of the coarse grassland tended to be more diverse at any one time, but cumulatively the fauna of the fine sward was slightly more diverse. Species predominant on the coarse grassland were Neophilaenus lineatus, Conosanus obsoletus, Mocydia crocea, Cicadula persimilis, Stenocranus minutus, Zyginidia scutellaris and Javesella pellucida (in the 2nd generation only). The last 4 species were abundant. Species predominant on the fine grassland were Deltocephalus pulicaris, Turrutus socialis, Euscelis incisus, Paluda adumbrata, Mocydiopsis attenuata, Dikraneura variata and Criomorphus albomarginatus. None of these species was abundant. Arthaldeus pascuellus was significantly more numerous on the coarse sward in summer 1974, but much more abundant on the fine sward in summer 1975. Mixtures of many grass species should be used to establish patches of grassland of variable structure and composition. -from Author
