The ratio of sunflower pollens foraged by apis mellifera is more than that of apis cerana does during sunflower blooming

Abstract

Bias foraging of pollen is general in different pollinators since various nutrition demanding, co-evolution and interaction of insect-plant. To clarify the preference of pollen foraging during sunflower blooming, the pollen foraging behaviors of Apis mellifera Linnaeus and Apis cerana Fabricius were observed. Our results displayed that two summits of pollen foraging occurred in the morning before the ambient temperature climbed up to thirty-one degree centigrade and in the afternoon after the ambient temperature decreased below thirty-one degree centigrade, respectively. Notably, the first foraging summit of Apis cerana emerged one hour earlier than that of Apis mellifera. These results imply that Apis mellifera is less resistant to low temperature but more resistant to high temperature than Apis cerana does. The colonies were surrounded by sunflowers with sporadic weeds, while only few maize dispersed over two hundred meters away. However, no more than forty percent of total pollens foraged by Apis mellifera was from sunflower, and which was no more than twenty percent in Apis cerana group. These results suggest that sunflower pollens are not the prior choice for both honey bee species, while the ratio of sunflower pollens foraged by Apis mellifera is more than that of Apis cerana does.