Notes on the feeding of Ectemnorrhinus similis waterhouse (Curculionidae) adults on Marion Island.

Little is known regarding the role of arthropods as herbivores on subantarctic islands. In grassland and drainage line communities on Marion Island maximum densities (up to 220/m2) of Ectemnorrhinus similis adults occur in March to April, representing a maximum biomass of ca. 1 g m-2. Captured beetles ingest approximately 14% of body weight per day of Acaena magellanica leaf material and 37% of body weight per day of Brachythecium rutabulum fronds. No significant feeding on Poa cookii leaves was observed. It is proposed that E. similis be regarded as a significant primary consumer on the island.