Pollination of Grewia asiatica (Malvaceae) by Megachile cephalotes (Hymenoptera: Megachilidae): Male vs. Female Pollination

The difference in behavior and morphology of male and female solitary bees-owing to different roles they perform- may alter their pollination effectiveness. The present study was aimed to study the difference in foraging behavior of male and female Megachile cephalotes Smith (Megachilidae) and its ultimate impact on pollination efficiency in terms of pollen deposition, fruit setting and post-harvest characters of phalsa crop, Grewia asiatica L (Malvaceae). The effect of different environmental factors (light intensity, temperature, relative humidity and wind velocity) on foraging behavior was also studied. Visitation frequency, visitation rate and pollen deposition of females were significantly higher than that of males. Female individuals had also an edge over male counterparts by having longer body and proboscis lengths. Males continued their activity throughout the day in low abundance without notable fluctuation while females attained their peak at 12:00 pm followed by a gradual decline until 4:00 pm. The maximum average fruit weight was recorded for female M. cephalotes pollinated fruits followed by open and male pollinated fruits. The shelf life in terms of post-harvest fruit weight and wrinkling was notably lower and more gradual in female pollinated fruits than open and male pollinated fruits. Our results suggest that female M. cephalotes are better pollinators of G. asiatica in terms of its reproductive success and post-harvest parameters than the males. Future studies should consider the biology and ecology of M. cephalotes with special focus on its artificial nesting.