UTTAR PRADESH JOURNAL OF ZOOLOGY

Mustard (Brassica juncea L.) is an important oilseed crop in India, and its productivity is influenced by insect-mediated pollination. The present investigation compared the foraging behaviour of five bee species—Apis dorsata, Apis cerana indica, Apis mellifera, Apis florea and Tetragonula sp.—on mustard flowers. Observations included the initiation and cessation of pollen and nectar collection, the number of flowers visited per minute, the number of pollen and nectar foragers returning to hives, time spent per flower, foraging speed and foraging rate. Tetragonula sp. initiated pollen collection earliest, at 06:50 h, and continued until 18:10 h, indicating the longest daily pollen-foraging period. During pollen collection, A. dorsata visited the most flowers per minute (8.33), followed by A. mellifera (6.59) and A. cerana indica (6.12). In managed colonies, returning pollen foragers peaked at 12:00 h, whereas nectar foragers peaked at 16:00 h. The lowest mean time spent per flower was recorded for A. cerana indica (3.16 s), followed by A. mellifera (3.76 s) and A. dorsata (4.04 s); Tetragonula sp. recorded the longest mean time (20.12 s). A. cerana indica also showed the highest mean foraging rate (19.12 flowers min⁻¹), whereas Tetragonula sp. showed the lowest (3.12 flowers min⁻¹). These findings demonstrate interspecific variation in foraging performance under the study conditions.