Species Richness and Seasonal Activity of the Leaf Cutter and Resin Bees (Hymenoptera: Megachilidae) at Pantnagar

The investigation on diversity, species richness and seasonal activity of the native megachilid bees carried out in different ecosystems during March, 2013 to April, 2015 at Pantnagar revealed occurrence of 19 species including 7 leaf cutter bees (Megachile albifrons, M. anthracena, M. bicolor, M. chlorigaster, M. conjuncta, M. relata, M. studiosa), 5 resin bees (M. cephalotes, , M. disjuncta, M. hera, M. inepta, M. lanata, M. umbripennis) and 7 other species viz. M. binghami, , M. elizabathae, M. femorata, M. gathela, M. rajasthaniensis and M. tetradenta. Our results show that species richness of megachilid bees was maximum in the month of April (18 species) followed by March and May, and October- November when 10-11 species were recorded in the field. About 58 percent of the total species had two peaks of their activity with 2-3 generations in a year. Minimum activity of species of megachilid bees was recorded during Dec- Feb (0-5 species, winter season) and July- Sept (2-4 species, rainy season). The resin bees, M. cephalotes and M. disjuncta were mulitivoltine in nature and were active almost throughout the year. Effect of abiotic factors on the seasonal activity of the native megachilid bees has also been discussed.