Checklist of moths ( Heterocera ) of Tadong , Sikkim , India

This study attempts to create a checklist of moths recorded from two different parts of Tadong in Sikkim, located in the northeastern Himalaya of India. Out of 160 photographed specimens of moths, 133 species were identified and classified. Sixteen families of moths were recorded out of which Erebidae (30.83%) had the highest number of species followed by Geometridae (24.81%), and Crambidae (18.05%) while the other families comprised of 26.30% of the total species.

ISSN 0974-7907 (Online); ISSN 0974-7893 (Print) Sikkim, a northeastern Himalayan state, is known for its biodiversity and strategic location surrounded by Nepal, Bhutan, and China. Several new species of butterflies, insects, and birds have been identified in the region (Kalawate 2018), but there are few reports on the sighting or identification of moth species. They play important roles in ecosystems as pollinators for many plants, and they are food for many predators, including bats and birds (Scoble 1992).
The State Fauna Series holds records of moths from Ctenuchidae and Limacodidae, with 24 species and 40 species, respectively , Saturniidae with 26 species (Gupta 2003), Zygaenidae with 66 species (Bhattacharya 2003), Arctiidae with 182 species , and Geometridae with 265 species (Ghosh 2003 The aim of the present study is to create a baseline checklist of moths from Tadong region in Sikkim for further update and addition to the inventory of moths of Sikkim.  (Table 1). Study sites are located between two watercourses, Rani Khola and Rorochu. The region has taken on urban characteristics as land resources have been encroached continuously due rapid unplanned development ( Figure 1d) (Chettri & Lama 2014). There is a gradual change in vegetation from alpine to subtropical and temperate deciduous forest in the region (Tamang et al. 2005). The temperature has been increasing in recent decades and precipitation fluctuates each year (Kumar et al. 2020).
The survey included photographing moths near the light sources using a smartphone camera (12MP).

Results and Discussion
During the study a total of 160 individual moths were photographed, from which 133 species were identified from the region. Of the identified specimens 112 were identified to species level, and 21 to the genus level (Images 1-133). Looking at species contribution to the diversity it was found that family Erebidae had the highest number of moths with 41 species, followed by Geometridae with 33 species and Crambidae with 24 species. Other families including Noctuidae, Notodontidae, Pyralidae, Drepanidae, Eupterotidae, Nolidae, Zygaenidae, Bombycidae, Limacodidae, Lasiocampidae, and Thyrididae accounted for 26% of total species (Table 2, Figure 2). All the identified species are listed in Table 3. Diversity indices were calculated using Past3 software, which showed Fisher's alpha, Shannon index, evenness, and Chao-1 to be 4.752, 1.975, 0.4504, and 21, respectively. Hence, the species diversity seems quite high. These values could be later used to collate species diversity (abundance, richness, evenness) of moths of this region.

Conclusion
In this study, we have attempted to create a baseline checklist of moths from Tadong, Sikkim region. This work adds to the inventory of moths of this region which could be utilised for future studies.   Note: 1) Survey sites: Gairi Gaon (GG) and 6 th Mile (SM); 2) Months observed: Includes months on which the species were sited which might indicate flying duration or seasonal presence; 3) Scientific name: Genus level identifications are represented as sp. Provisional identifications as cf. or near, the former for close matches and the latter for poor matches.