Major Advisor: Prof Durga Dutta Dhakal (Ph D)
- Resham Bahadur Thapa (Ph D)
- Durga Mani Gautam (Ph D).
A field study was conducted at IAAS, Rampur, Chitwan, Nepal to evaluate the foraging preference of three species of honeybees, Apis cerana Fab, Apis mellifera Lin, and Apis dorsata Fab to litchi (Litchi chinensis Gaertn), citrus (Citrus spp), bottle brush (Callistemon lanceolates Lin), cucumber (Cucumis sativus Lin), radish (Raphanus sativus Lin) and summer squash (Cucumis pepo Lin) during their blooming season, February to April 2001. Foraging of honey bees at 7:30 and 11:00 AM and 3:00 and 5:30 PM during early, mid and late seasons of flowering was assessed. Honey bees foraging at different times of day during early, mid and late periods of flowering differed significantly. A. mellifera visited to all six selected species of horticultural plants showing better foraging efficiency over a wide range of floral diversities. A. dorsata visited to litchi, citrus, bottle brush and summer squash flowers while A. cerana visited only to radish and litchi flowers. Litchi flowers \were \the most preferred source of nectar whereas cucumber was the least preferred by all three species of honeybees. The highest number of A. mellifera (7.04/m2/min) foraged on litchi at late morning followed by A. dorsata (6.83/m2/min) at early morning and A., cerana (2.58/m2/min) at late morning during its mid flowering period. A. mellifera spent less time (2.6±1.0 sec/flower) and foraged maximum number of flowers (19.1±3.0 flowers/min) followed by A. dorsata (2.9±1.0 sec/flower) and A. cerana (3.1±1.0 sec/flower) foraging 17.9±6.2 and 156.1±3.0 flowers/min respectively. Citrus flowers were visited by the maximum number of A. mellifera honeybees (5.16/m2/min) in the late morning followed by A. dorsata (1.58/m2/min) in the early morning hours for pollen collection during its mid flowering period. A. dorsata spent less time (10.4±4.0 sec/flower) and visited to more number of citrus flowers (5.1±3.0 flowers/min) than A. mellifera which spent 28.6±3.0 sec/flower and visited 2.1±1.0 flowers/min. A. mellifera and A. cerana spent 4.2±2.0 and 7.0±2.0 sec/flower and visited 7.6±3.0 and 7.2±2.0 number of flowers/min, respectively to radish flowers in the morning hours for pollen collection. Bottle brush flowers were foraged more preferentially by A. dorsata (8.04/m2//min) and A. mellifera worker bees (5.12/m2/min) at early morning and late afternoon, respectively, during the early flowering period of the plant both for pollen and nectar collection. From the study it is evident that the knowledge of foraging preference and efficiency of different honeybee species and flora available around the vicinity of the crop largely determines the species of honeybees and number of colonies required for successful pollination and bee hive productions.