THE AUCHENORHYNCHA OF AN UNIMPROVED MOORLAND IN NORTHERN ENGLAND

1. Auchenorhyncha were sampled at seventy-four sites within an upland Calluna moorland/acidic grassland in Northumberland, England. Quantita tive data on vegetation structure, plant species cover and soil condit ions were also collected at each site. 2. Classification of the Auchen orhyncha species lists using two-way indicator species analysis identi fied three groups of assemblages ('communities') occurring at sites wh ich appeared to differ in vegetation and soil conditions. 3. Canonical correspondence analysis revealed that four factors alone explained 21 .1% of the between-site variation in Auchenorhyncha species lists. The se were species richness of grasses, soil pH, and covers of woody plan ts and sedges. Inclusion of further variables did not significantly in crease the variation explained. 4. The distributions of individual spe cies of Auchenorhyncha, and hence the species composition and species richness of assemblages, were strongly influenced by the distributions of host plants. 5. Auchenorhyncha species richness was greatest at si tes with the least acid soils and the highest covers and numbers of gr ass species. Sites dominated by sedges and woody plants supported the fewest species of Auchenorhyncha.