Community Structure and Seasonal Dynamics of Moth Assemblages in Sal (Shorea robusta) Forests of the Shiwalik Ranges, Uttarakhand, India

A study was carried out to know species composition, diversity and seasonality of macro-moths in the Sal (Shorea robusta) Roth (Dipterocarpaceae) forests (n=4; Timli, Naudi-Mundiapani, Chilla and Chorgaliya) in the Shiwalik ranges of Uttarakhand, northern India. Seasonal surveys were conducted using moth screen over 56 days, spanning 168 sampling hours from July 2020 to October 2023, across pre-monsoon, monsoon, and post-monsoon periods. A total of 2,377 individuals representing 231 species of macro-moths, belonging to 18 families and 48 sub-families, were recorded, indicating a high level of diversity. This included 04 new range extensions into Northern India from Southeast India, Central (Nepal), and Eastern Himalaya. Two annual peaks were observed in Sal forests; the first peak occurred earlier in August (monsoon), while the second occurred in October (post-monsoon). Family Erebidae (68) was the most dominant, followed by Crambidae (48), Geometridae (47) and Noctuidae (20), respectively; while a low number of species was recorded in the families Notodontidae (1), Pyralidae (1) and Zygaenidae (1). Naudi-Mundiapani forests site had the greatest Shannon & Simpson diversity (4.377 & 0.9805). Over 123 moth species were recorded in ‘Naudi-Mundiapani’ forest, making it a unique habitat for macro-moths. Naudi-Mundiapani forest site exhibited a distinct moth community structure. A number of habitat-restricted and rare moth species were recorded during the survey, including; Brahmaea hearseyi (White, 1862), Agrotera scissalis (Walker, 1866) Parapoynx bilinealis (Snellen, 1876), Ischyja marapok (Holloway, 2005), Achaea serva (Fabricius, 1775), Sarobela litterata (Pagenstecher, 1888), Diomea lignicolora (Walker,1858), Fascellina chromataria (Walker, 1860), Cania bilinea (Walker, 1855), Antheraea assamensis (Helfer, 1837), and Episteme adulatrix (Kollar,1884) and Ramadasa pavo (Walker, 1856). There is still potential for recording additional species, as species richness estimators indicated a much higher estimated richness than the observed number of species (Chao 2: 544; Jackknife 1: 349; Jackknife 2: 412). These findings highlight Shiwalik Sal forests as important ecological and biodiversity hotspots supporting seasonally dynamic moth communities, rare habitat-restricted species, and serving as ecological refuges within the Shiwalik range.