Diurnal hawkmoths as alternative pollinators for bitter gourd

Bitter gourd, Momordica charantia L. (Cucurbitales: Cucurbitaceae), is a major vegetable crop in tropical and subtropical regions. Honeybees are considered the primary pollinators of bitter gourd, but they often favor male flowers, which offer nectar and pollen rewards, over female flowers, which do not. This preference can lead to pollination deficiency in bitter gourd. Therefore, exploring alternative pollinators for bitter gourd is crucial to ensure efficient pollination and optimal fruit production, especially in greenhouse settings where honeybee pollination may be less effective. We investigated the pollination efficiency of diurnal hawkmoths and compared it with that of honeybees, bumblebees, and small bees. Our findings revealed that hawkmoths exhibit equal visitation rates to both male and female bitter gourd flowers and deposit a significantly greater number of pollen grains per visit than those bees. This high pollination efficiency, combined with their nonselective flower visitation behavior, makes hawkmoths a promising alternative pollinator for bitter gourd. Our results suggest that hawkmoths could be effective pollinator agents for bitter gourd, especially in greenhouse settings. This discovery opens up new possibilities for sustainable agriculture and could lead to improved pollination strategies for bitter gourd and other cucurbit crops.