Seasonality, diversity, and forest type associations of macro moths (Insecta: Lepidoptera: Heterocera) in the Shiwalik landscape of northern India and its conservation implications

Abstract

A study was carried out to evaluate the seasonal diversity of macro moths across different forest sub-types occurring in theShiwalik landscape of northern India, mainly Uttarakhand and adjoining states of Himachal Pradesh, Uttar Pradesh, and Haryana. Fortythree field surveys of 59 days were carried out from July 2020 to October 2022 using stratified random sampling in each of the 19 selected study sites. Sampling surveys revealed 321 species of moths belonging to 19 families and 49 sub-families. These new range extensions from central Himalaya and northeastern India indicate the affinity of moths found in the northern Indian Shiwaliks with that of the Oriental region. Seasonal trend of species richness showed two annual peaks, with the first peak occurring in August followed by a smaller peak in October, while the seasonal abundance of moth species was maximum in July followed by a smaller peak in September. One-hundredand-forty species occurred only during the ‘monsoon’ season indicating their seasonality, univoltine habit and short flight periods in these tropical forests. Species richness of moths correlated positively with relative humidity (r2 = 0.100; p = 0.0142; n = 59). The most dominant family was Erebidae (95 species) followed by Geometriidae (61), Crambidae (72), and Noctuidae (28), respectively. Maximum number of moth species were sampled in forest sub-type (i) 3C/C2a Moist Shiwalik Sal Forest, followed by (ii) 5B/C2 Northern Dry Mixed Deciduous Forest, (iii) 3C/C2c Moist Tarai Sal Forest, iv) 5B/C1a Dry Shiwalik Sal Forest, respectively. The study also revealed changing moth communities along with the vegetation structure in the Shiwaliks from east (Nandhaur Willife Sanctaury in Uttarakhand bordering Nepal) to west (Simbalbara National Park in Himachal Pradesh,India) across the landscape. The moth communities of (i) 3C/C2a Moist Shiwalik Sal Forest & (ii) 3C/C2c Moist Tarai Sal Forest being different from that of (iii) 5B/C2 Northern Dry Mixed Deciduous Forest, and (iv) 5B/C1a Dry Shiwalik Sal Forest. Besides, six new range extensions into Shiwaliks of northern India from central Nepal and northeastern India, namely: Chlorozancla falcatus (Butler, 1889) (Geometridae); Cynaeda dichroalis (Hampson, 1903), Dichocrocis pyrrhalis (Walker, 1859) & Glyphodes canthusalis Walker, 1859 (Crambidae); and Acropteris iphiata (Guenée, 1857) (Uranidae) were recorded.