Oviposition-site preferences of a declining butterfly Erebia medusa (Lepidoptera: Satyrinae) in nutrient-poor grasslands

摘要: Butterflies belong to one of the most intensively studied invertebrate groups. However, detailed information on larval ecology is still lacking in many species. This especially true for grass-feeding subfamily Satyrinae, which our study species, Woodland Ringlet (Erebia medusa Fabricius, 1787), belongs. At habitat level, E. exhibits a clear preference abandoned grasslands with litter accumulation. In this study, we assessed host-plant and oviposition preferences at microhabitat i.e., within occupied patches, Diemel Valley (Central Germany). Only two species grass, Festuca ovina agg. F. rubra agg., were systematically used oviposition. Egg density was positively correlated patchiness herb layer, potential daily length sunshine, abandonment. explanatory power these parameters low. We attribute primarily an ample supply host plants growing under suitable conditions patches medusa. The positive effect abandonment probably due fact that average height sites greater than other satyrine renders eggs more vulnerable mechanical disturbance. Moreover, thick layers litter, develop after cessation grazing or mowing, might be important as they modify microclimate locations immature stages.