Host and nectar plant interactions of Swallowtail butterflies (Lepidoptera: Papilionidae) in the Kumaun Himalaya, Uttarakhand, India

Butterflies are important forest ecosystem components and serve as valuable indicators of forests. Pollinator-plant mutualism forms complex networks that vary across spatial scales under the influence of environmental gradients. The availability of larval food plants, suitable egg-laying sites, the presence of nectar-rich flowers for feeding adults, habitat quality, and the quality of semi-natural and natural habitats are crucial factors that govern the distribution patterns of butterflies. Most of the Himalayan forest habitats have been affected in recent decades due to various anthropogenic activities. The decline of swallowtail butterflies in forest habitats has garnered global attention, resulting in their status as globally endangered by the International Union for Conservation of Nature. Therefore, it is necessary to explore the diversity of swallowtail butterflies and identify their fostering host plants for their conservation. The present study explores the urban and natural habitats of the Kumaun region of the Western Himalaya to document the flora that serves as larval and adult nectar host plants for the swallowtail butterflies. The study recorded 66 plant species from 25 families, including 45 species from 11 families serving as hosts to larvae and 21 species from 11 families serving as nectar resources and fostering the growth and development of swallowtail butterflies in the Kumaun region of Uttarakhand. The study provides valuable insights into the behavioral strategies and ecological roles of butterflies, which will be helpful for further research and conservation.