Species diversity and abundance of Odonata in Sishaghat of Tanahun district, Nepal

Odonates are one of the most ancient, well studied and fascinating insects considered as bio-indicators of aquatic ecosystems. Studies of Odonata have been carried out in many parts of Nepal, but no specific study has been performed in Tanahun. Hence, a study was conducted to determine the species diversity and abundance of Odonata in the Sishaghat region of Tanahun district, Nepal from June to August ۲۰۲۰. A transect survey method was used for data collection. A total of six transects, each with a length of ۲۰۰ m: - (three in each habitat type: agricultural lands and forest streams) were laid out randomly and each transect was surveyed three times. Data were pooled and analyzed with SPSS. A total of ۶۲۹ individuals of ۲۶ Odonata species from ۲۰ genera and ۷ families were recorded. The overall Shannon-Wiener diversity index was H= ۲.۲۵, Shannon Equitability was E= ۰.۶۹ and Margalefs’ richness index was R= ۳.۸۸. Sub-order Anisoptera was more diverse (H= ۱.۹۴) and more abundant (n= ۵۴۵) than Zygoptera (H= ۱.۳۱, n= ۸۴). However, species richness was higher and evenness lower in Zygoptera (R= ۲.۲۶, E= ۰.۵۵) than Anisoptera (R= ۲.۲۲, E= ۰.۷۲). Anisoptera comprised ۱۵ species under ۱۰ genera from two families and Zygoptera comprised ۱۱ species under seven genera from five families. The family Libellulidae represented the highest species richness (R=۱.۷۵). Neurothemis fulvia and Orthetrum pruinosum were the most abundant species (RA= ۲۳.۲۱ and ۲۱.۷۸ respectively). While considering the global context, among the recorded Odonata, ۲۵ species are included under the least concern and one under the vulnerable category by IUCN. A higher number of species was found in agricultural lands (nine species); hence, the water bodies around should be preserved to conserve the Odonata.  

کلیدواژه ها:

Calicnemia nipalica ، Damselfly ، Dragonfly ، Flier ، Percher ، Libellulidae