Foraging activity of Indian honey bee Apis cerana, in relation to ambient climate variables under tropical conditions

Abstract

Climate plays a significant role in influencing the foraging behavior of social insects especially honey bees. We conducted studies at Indian Institute of Horticultural research, Bengaluru during 2011-13 to assess the effect of four abiotic factors viz., temperature, relative humidity (RH), rainfall and wind speed on the foraging activity of Indian honey bee, Apis cerana. Foraging activity was determined in terms of the number of worker bees going out and coming in per five minutes at 8.00, 12.00 and 4.00hrs. Significant diurnal and seasonal variations were recoded. Among all climatic factors, maximum temperature was the most crucial one which had negatively affected the bee activity with correlation coefficients of -0.72, -0.59 and -0.61 for out going bees, pollen and nectar collectors respectively. Regression equation explained up to 68% variation due to maximum temperature. The minimum temperature and relative humidity had positive impact on out going bees but negatively affected the number of pollen collectors. The number of worker bees going out to forage has come down significantly after 30oC. Diurnal variations showed that the peak activity of bees occurred in the morning hours. Rainfall hampered the foraging activity while the wind speed was found to have no significant effect on bee activity.