Pollinator diversity and pollination efficiency of stingless bee Tetragonula iridipennis Smith in bitter gourd

An experiment was conducted out to investigate the pollinator diversity and pollination efficiency of Tetragonula iridipennis Smith on bitter gourd (Momordica charantia L.). In this study, there were 16 floral visitor species were recorded. Among them, six species were the most frequent visitors. A highest mean of visits was recorded with Halictus sp. (7.80) during 1000-1200 hrs in relative abundance and the lowest was of Megachile sp. (2.90) at 1600-1800 hrs. The foraging rate of stingless bees was most active in morning 1000-1200 hrs. The maximum fruit set was observed in pollinator-imposed fields (80.23 %) compared to pollinator excluded fields (71.15 %). Prominent increase in fruit length and girth in the pollinator included plots were respectively observed to be 249.19 and 42.91 mm. Maximum number of fruit/ individual plant (24.10) was achieved with bee pollination as compared to control (21.20).