Sikkim Mandarin Orange (Citrus reticulata Blanco, 1837) is a member of the Rutaceae family and a commercially desirable variety of the mandarin group native to Sikkim. The Sikkim Mandarin Orange (SMO) growing area lies at an altitudinal range of 700–1,500 m and it is an annual flowering plant. Mandarin orange is dependent on bees for its pollination and pollinators help in higher yield and increased fruit set (ICIMOD 2003). Irrespective of large cardamom yield decline due to pollinator deficiency in Sikkim (Sinu & Shivanna 2007), till date there exists no systematic study on the range of pollinators for SMO. This study aims to bridge this gap especially when a large proportion of farmers are dependent on the SMO for cash income. Our study area spanned the East, West and South districts of Sikkim. The southern part of the state, which lies in the altitude range of 600–1500 m provides an ideal climate for SMO cultivation (DHCCD 2015). Data was collected across 72 SMO orchards from 2011 to 2013. These orange orchards were selected within an altitudinal gradient of 700–1,452 m and were spread across 316km2 (Fig. 1). Pollinator visitation: At each site, 150 flowers were tagged and observed from 08.00–17.00 h to record insect species that visit them. Intra-floral foraging behavior of each insect species was carefully observed to note whether it is a pollinator or a forager. SMO bear self-fertile, bisexual flowers and pollen movement is facilitated by pollinators. Transparent plastic bags were used to trap insects visiting the flowers to avoid any fruit loss during their collection. Collected samples were preserved in 70% ethanol and subsequently identified in the laboratory. Insects which were not seen touching the flower reproductive parts were not collected for identification.