Hoverfly pollination enhances yield and fruit quality in mango under protected cultivation

•Hoverflies release improves pollination of mango cultivated in a greenhouse.•Eristalinus aeneus shows a significant pollen transport capacity and a high visitation rate.•Hoverfly-pollinated trees produced up to 240% more fruits than those without insects.•Adding 30 hoverflies/m2 improves yield and fruit quality in protected mango crops. Mango (Mangifera indica L.) is one of the main tropical fruit crops worldwide. Although mostly grown in open fields, protected cultivation of mango has recently increased. Pollination in mango mainly occurs by flies (myophily) among which the group of eristaline hoverflies (Diptera: Syrphidae) stands out. Greenhouse studies were conducted on the pollination services provided by Eristalinus aeneus released at three densities in a protected mango orchard in southern Spain, during two consecutive seasons (2019 and 2020). Medium and high densities (30 and 45 individuals per square meter, respectively) led to higher number of floral visits to the middle and apical portions of the inflorescences where hermaphrodite flowers are more common, which resulted in more pollen grains being transferred to the stigma of fertile flowers. Medium and high densities of E. aeneus increased yields and improved fruit quality compared to low density (15 individuals per square meter), no insect release, and conventional pollination management using bumblebees. Yield enhancement achieved by using hoverflies as pollinating agents at medium and high densities implies an economic gain for farmers ranging from 16% to 29% in 2019 and from 212% to 456% in 2020. Therefore, our results suggest that medium and high densities of E. aeneus are profitable pollination solutions for mango cultivated under greenhouses.