Pollination efficiency and foraging behaviour of honey bees and flies to onion <i>Allium cepa</i> L.

Bees and flies are the most common visitors to onion flowers in Karnataka, but evidence for their pollination efficiency is lacking. Hence, experiments on behavioral observations were recorded using four bees (Apidae: Hymenoptera) two (Syrphidae: Diptera) species visiting (Allium cepa L.) at experimental fields of ICAR-Indian Institute Horticultural Research, Bengaluru, India (13.13°N; 77.49°E) during 2020-2021. Pollinator effectiveness (PE) measured as pollen deposition stigmas per visit. Honey mainly collect nectar stingless (81.90%), bringing latter into intimate contact with stigma more frequently. Stingless bees, honey often seen foraging together same umbel, no antagonistic interactions observed. The rock bee (Apis dorsata) deposited a maximum number (34.60) visit followed by (24.45). pollinated had higher seed set percentage; weight 1000 seeds average seeds/umbels compared deprived pollinators. results allowed us conclude that effective pollinators onions. Further work needed determine optimum population required maximizing yield onion.