Diversity and Abundance of Odonata Species in Mt. Busa, Lake Sebu, South Cotabato, Philippines

Odonata is dependent on environments with standing or moving water. Its sensitivity to changes in water habitats makes it a valuable biological indicator. This study was conducted on Mount Busa, Municipality of Lake Sebu, South Cotabato, which has relatively conserved montane forests and streams that meander through it, making it a key biodiversity area; also, no previous data on Odonata exists. Thus, this study specifically sought to (1) determine the species composition, abundance, endemism, conservation status of dragonflies and damselflies; (2) compare the species diversity of dragonflies and damselflies across sampling sites; (3) correlate measured physicochemical parameters to the distribution of dragonflies and damselflies across forest type and elevation. Field sampling was conducted from October 31 to November 2, 2022, along established sites in open habitat, and lower montane open forest part of Mt. Busa. Opportunistic sampling using sweep net and photo documentation were used during the study. A total of 104 Odonata individuals were observed, comprising 12 species from 5 families, including 8 dragonfly (Anisoptera) and 4 damselfly (Zygoptera) species. Out of the 12 species, 5 were found to be endemic. Specifically, Igneocnemis atripes and Igneocnemis tendipes were endemic to Mindanao. Orthetrum pruinosum clelia and 1. atripes were the most abundant dragonfly and damselfly species, respectively. Mt. Busa exhibited moderate species diversity, with both evenly and unevenly distributed species across the sampled sites. Site 3, situated in the lower montane forest, had the highest species richness (S - 9) species diversity (H' = 2.15) and ENS(8.58) indicating that it is a relatively healthy ecosystem and is of high conservation importance. Canonical Correspondence Analysis demonstrated a correlation between the abundance of Odonata species and the measured physicochemical conditions in the area.