Comparative micro-computed tomographic analysis of the structure of brood cells and its effect on the development of the pupae of honey bee (Apis mellifera)

Abstract

Most beekeepers worldwide use the same combs in their hives for many years, which can result in alterations in the inner volume of the comb cells. The objective of this survey using microcomputed tomography was to reveal developmental disorders caused by this beekeeping practice. The extent of the thickening of the wall of brood cells that occurs as a result of the long-term use of the combs was determined. This alteration resulted in a reduction in the inner volume of the comb cells, which had a significant effect on the size of the pupae and possibly the health of the imagoes. The walls of the cells can be divided into two well-determined parts, which can be exactly visualized using micro-CT. In addition, the inner structure of the wall in the first part of the cell was altered by very radio dense remains of cocoons. The material in the other part of the cell is less radio dense and as previously suggested is mainly wax. The decrease in the length, surface and volume of these cells adversely affected the developing pupae, which according to previous studies results in a reduction in the production of workers, colony strength and honey yield. The extent of the reduction in the body regions of pupae was on average 4.98%. Overall, the volume of the pupae that developed in these narrow comb cells were smaller by an average of 12.22%.