Diversity and abundance of butterflies (Lepidoptera) in Byas municipality of the Tanahun district, Nepal

Butterflies are flagship taxa and bio-indicator of terrestrial ecosystems. Studies of butterflies are performed in different regions of Nepal, but no detailed research has been carried out in Tanahun. Hence, this study was conducted to determine the species diversity and abundance of butterflies in Byas municipality-6 of the Tanahun, Nepal, from March to November 2020. The Pollard walk method was used for the data collection. A total of six transects of 500 m, two in each habitat type (forests, settlements, and agricultural lands), were laid out randomly. The study was performed in three seasons (9 months); Pre-Monsoon (March to May), Monsoon (June to September), and Post-Monsoon (October to November). Each transect was surveyed nine times (once a month) to record species in each month. Data were pooled and analyzed with SPSS. A total of 1,753 individuals of 149 butterfly species from 92 genera and six families were recorded during the study. The overall Shannon-Wiener and Margalef diversity indices were H = 4.17 and R = 19.95. Pielou’s Evenness was E = 0.83. Nymphalidae was the most diverse, richest species, and most abundant family (H = 3.33, R = 8.30, N = 851). Species evenness was maximum in the family Papilionidae (E = 0.88). The forests comprised the maximum number of species (115 species, 898 individuals). The maximum number of species was recorded in March (106 species), while the highest species abundance was in June (268 individuals). The result of this study could be the baseline for further researches on butterflies in the Tanahun district.