Comparative studies on pollen loads and pollen constancy of Apis mellifera L. and Apis cerana indica F. on rapeseed

Comparative studies on the pollen loads of Apis mellifera L. and Apis cerana indica F. were undertaken on rapeseed, Brassica campestris var. sarson during 1990–91 rabi season. A. mellifera bees on an average carried heavier pollen load (13.28 ± 0.783 mg) than A. c. indica (11.33 ± 0.718 mg). However, the pollen loads of the two species did not differ significantly. The pollen loads carried by A. mellifera and A.c. indica at 0900, 1200 and 1500 h of the day were also not significantly different. A. mellifera bees carried maximum average pollen load at 1200 h, whereas A.c. indica bees carried maximum average pollen load at 0900 h. Both the species carried minimum average pollen loads at 1500 h. The pollen loads of both the species differed according to the time of the day and on different days. Both the species showed almost alike pollen constancy to the rapeseed crop.