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

Abstract

Odonata are one of the most ancient, well studied and fascinating insect orders considered as bio-indicators of aquatic ecosystems. Studies on 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 of Tanahun district, Nepal from June to August 2020. A transect survey method was used for data collection. A total of six transects (three in each habitat type: agricultural lands and forest streams), each with a length of 200 m were laid out randomly and each transect was surveyed three times. Data were pooled and analyzed with SPSS. A total of 629 individuals of 26 Odonata species from 20 genera and 7 families were recorded. The overall Shannon-Wiener diversity index was H= 2.25, Shannon Equitability was E= 0.69 and Margalefs' richness index was R= 3.88. Sub-order Anisoptera was more diverse (H= 1.94) and more abundant (n= 545) than Zygoptera (H= 1.31, n= 84). However, species richness was higher and evenness lower in Zygoptera (R= 2.26, E= 0.55) than Anisoptera (R= 2.22, E= 0.72). Anisoptera comprised 15 species within 10 genera from two families and Zygoptera comprised 11 species within seven genera from five families. The family Libellulidae represented the highest species richness (R= 1.75). Neurothemis fulvia and Orthetrum pruinosum were the most abundant species (RA= 23.21 and 21.78 respectively). Of the recorded Odonata, 25 species are included under the least concern and one under the vulnerable category of the IUCN. A higher number of species was found in agricultural lands (nine species); hence, the water bodies around this habitat should be preserved to conserve the Odonata.

Diversity and Abundance of Butterflies (Lepidoptera: Rhopalocera) in Sethu Bhaskara Agricultural College and Research Foundation, Karaikudi, Tamil Nadu, South India

“…No. Similarly, a high number of species from Nymphalidae were observed by [44][45][46][47][48] in their studies. The highest species richness and abundance might be due to the presence of host plants suitable for Nymphalidae [49], high dispersal ability, ecological adaptation, being polyfag characteristic and strong or active flight, enabling them to search for resources in large geographical areas [6,[50][51][52][53].…”