Energy intake and expenditure as determinants of foraging decision in alfalfa pollinating carpenter bee Chalicodoma cephalotes Smith

The energetics of foraging behaviour of alfalfa pollinating carpenter bee Chalicodoma (ex.Megachile) cephalotes F. was studied in relation to foraging on sunflower, Helianthus annus, Medicago sativa, Parkinsonia aculeata, Cajanus cajan and Pongamia glabra.Laboratory assessments of physiological energetics were combined with field observations on the time budget and energy intake of Chalicodoma cephalotes Smith to estimate its daily energy expenditure.The energy balance varied from day to day and across different crops.Overall, the foraging efficiency of C. cephalotes followed this order: C. cajan > P. glabra > P. aculeate > M. sativa > H. annuus.It was evident that C. cajan, P. glabra and P. aculeata provided more energy for the bees under the conditions of the present study.