Abstract: Stingless bee's pollination service is provisioned at various terrestrial ecosystems. Many flowering plant species are rely on stingless bees and in turn stingless bees are rewarded with nectar, pollen, resin, honeydew and nest-building materials with their minimum flight range amidst natural and man-made ecosystems. However, published reports on floral source and floral calendar for stingless bees is poor. Hence, systematic investigation was undertaken at nine districts which represented maidan, malnad, hilly terrain, coastal region, arid zone and agro-ecosystems at the vicinity of Western Ghats by following standard methods. Beekeepers doing Meliponiculture were randomly selected and visited their apiary/meliponary to record the floral source in one square kilometer area during different seasons from 2023 to 2024. Flowering plants for their nectar, pollen and both nectar and pollen source were recorded and photographed by spending 10 minutes per plant/flower after confirming the visit of stingless bees during 0700 to 1800 hours of observation. Total 84 flowering plant species which belong to 45 plant families provided foraging source to stingless bees at different agro-ecosystems of Karnataka. Asteraceae and Rutaceae family members were more predominant (7.1% each) and it was followed by Cucurbitaceae, Lamiaceae and Myrtaceae family members (5.8% each) contributed good foraging source to stingless bees. Mimosaceae, Euphorbiaceae, Fabaceae and Solanaceae family members also contributed considerable amount of foraging source to stingless bees during different seasons. The floral source consists of avenue trees, commercial plants, fruit yielding plants, horticultural plants, medicinal plants, ornamental plants, vegetable crops and weeds which were grouped into climbers, herbs, shrubs and trees have provided foraging source at various agro-ecosystems. Floral calendar revealed the occurrence of pollen (P1, P2 and P3) and nectar (N1, N2 and N3) plants based on their potential source of both pollen and nectar (P1N1, P1N2, P1N3, P2N1, P2N2, P2N3, P3N1, P3N2 and P3N3) plants to stingless bees by blooming during different months around the year i.e., January to December. Thus, stingless bees avail good floral source during different seasons amidst apiary/meliponary at various agro-ecosystems that could help encourage Meliponiculture on large scale basis along with apiculture in Karnataka.

Keywords: Flora, stingless bees, Meliponiculture, Karnataka

| DOI: 10.17148/IARJSET.2025.12102