Habitat associations of day-flying Lepidoptera and their foodplants within nature reserves in Bedfordshire, UK

Species often associate with specific habitat characteristics, resulting in patchy distributions, whereby they only occupy a proportion of available habitat. Understanding which characteristics species associate with is a valuable tool for informing conservation management. We investigated the habitat associations of eleven species of day-flying Lepidoptera larvae and their foodplants within calcareous grassland reserves in Bedfordshire, UK, across two scales relevant to land managers and target species: the reserve (cardinal aspect, vegetation type) and foodplant patch scale (foodplant height and density). We investigated whether ecological traits (habitat specialism and overwintering life stage) influenced the strength of associations. At the reserve scale, we found variation in habitat associations across species, with species that overwinter at non-adult life stages having more restricted associations, indicating that they may be more vulnerable to environmental change. Associations were generally stronger with vegetation type than aspect, which can be manipulated more easily by land managers. Seven species had similar habitat associations to their foodplants, implying that management to benefit foodplants will also benefit larvae. However, the remaining four species had different habitat associations to their foodplants, and may require alternative management approaches. At the foodplant patch scale, four species were associated with foodplant characteristics, which could be used to inform effective fine-scale management.