Seasonal sampling surveys of macro-moths were conducted in the ‘moist temperate ban oak (Quercus leucotrichophora)’ (Western Himalaya) and ‘tropical moist deciduous sal (Shorea robusta)’ (the Shiwalik range) forests of Uttarakhand in Northern India. This was carried out to understand the differences in the species diversity, seasonality and community structure between these two forest types, located on two different mountain ranges that are geologically distinct. Eight locations (four in each forest) were taken up for study. The surveys covered 125 days and three seasons (pre-monsoon; monsoon; and post-monsoon). Moths were attracted to artificial light nightly after sunset from 1900 to 2200 hours, totaling 375 hours of sampling, and we used a CFL (27 Watts; 220-240 Volts) hung vertically in front of a white canvas cloth (moth screen: 180 x 120 mm).

This study revealed 451 species from 22 families (species richness estimators: Chao 2 = 948; Jacknife 1 = 709) in the ban oak forests as compared to 231 species from 18 families in the sal forests (Chao 2 = 544; Jacknife 1 = 349), respectively. The families Geometridae followed by Erebidae, Crambidae, Noctuidae, and Drepanidae were dominant in the ban oak forests, whereas Erebidae followed by Geometridae, Crambidae, and Noctuidae were dominant in the sal forests, respectively. Shannon's diversity index was higher in the ban oak forests (4.22) in comparison to that in the sal forests (3.923). The species richness and abundance showed two seasonal peaks annually: in the sal forests, the peaks occurred during ‘monsoon’, followed by ‘post-monsoon’, while in the ban oak forests, the first peak occurred during ‘pre-monsoon’, followed by a second peak during the ‘early post-monsoon’, respectively.

Non-metric Multi-Dimensional Scaling (NMDS) of the moth abundance across the eight sites and three seasons showed distinct moth communities. The sal forest sites exhibited greater moth similarity across sites, while the ban oak sites exhibited greater ‘beta diversity’, and this variation was more pronounced during the ‘post-monsoon’ season compared to the ‘pre-monsoon’ and ‘monsoon’ seasons. The moth communities in the sal and ban oak forests were thus determined to be distinct from each other in Northern India.