Pollinator Assemblages of an Underutilized Medicinal Tree (Terminalia arjuna): Diversity, Seasonality, and Conservation Needs

Abstract

Pollination is a vital biological process that enables the reproduction of flowering plants, and insect pollinators play a crucial role in maintaining biodiversity and ecosystem stability. This study investigated the diversity of insect pollinators visiting the flowers of Terminalia arjuna, an important underutilized medicinal tree in the Mandi District of Himachal Pradesh, India. Insect samples were collected using hand nets during the flowering period from April to July in 2019-2021 and identified at the Zoological Survey of India, Kolkata. The results revealed that T. arjuna flowers attracted a diverse array of insects belonging to 5 orders, 9 families, and 23 species. Dipterans were the most diverse group, with ten species from three families: Syrphidae, Tachinidae, and Calliphoridae. Hymenopterans were followed by six species from the Apidae and Vespidae families. Lepidopterans were represented by three species from Pieridae and Nymphalidae, while Coleopterans had three species from Coccinellidae. A single Hemipteran species from the Largidae family was also recorded. These findings are consistent with previous studies on pollination mechanisms in other Terminalia species, which reported entomophilous pollination by various insect orders. The study highlights the importance of insect pollinators in the reproductive success of T. arjuna and underscores the need for conservation measures to protect these essential species and their habitats.