Systematic survey on alpha diversity of anthophilous insect fauna in Binsar Wildlife Sanctuary, Western Himalaya

Abstract

Insects as pollinators or anthophiles are key components for proper functioning and long term sustainability of the agro and forest-ecosystems. Investigations undertaken to determine the status and diversity of insect pollinators in relation to the floristic composition in Binsar Wildlife Sanctuary (BWLS), Uttarakhand, India, revealed a total of 53 species of insects belonging to 18 families under four orders facilitating the pollination process in the entire area of the sanctuary. The species richness and value of Shannon Wiener diversity index (H’) was recorded highest for the order Lepidoptera i.e., 33 species and 3.064, followed by Hymenoptera (11 species and 2.233), Diptera (five species and 1.495) and Coleoptera (four species and 1.226), respectively. The members of order Hymenoptera were much more evenly distributed with highest 0.9313 value of Pielou’s Evenness Index (J’) in comparisons to the other orders throughout the study period. In addition, the three study sites which were selected in the BWLS exhibited a declining trend of pollinators’ alpha diversity along increasing altitudes. In the present study several plant species of families Asteraceae, Fabaceae, Rosaceae and Urticaceae constituted important foraging resources for insects throughout the years. Temporal variations in patterns of plant-pollinators interactions get affected by multiple environmental factors and different habitat types of BWLS, were also observed.