Comb Cell Structure and Morphological Characteristics of the Chinese Honey Bee, Apis cerana cerana (Hymenoptera: Apidae), Under Successive Generations.

This study investigated the changes in comb cell structure and external morphological characteristics of the Chinese honey bee under ten successive generations to determine the optimal time to replace the old combs. Accordingly, ten Chinese honey bee experimental colonies were established, and natural combs were constructed for continuous rearing of workers for 1-10 generations. The brood comb thickness, brood cell structure, birth weight, and morphological characteristics of workers were determined. Pearson correlation analyses between brood comb structure and morphological characteristics of workers were carried out. The results revealed that under ten successive generations, the color of the brood comb deepens from white or light yellow to brown and finally to black. Also, concerning the brood cell shape, the cell base changes from the three-rhomboid structure to the hemisphere, and the cell body changes from the hexagonal prism structure to the cylinder. The brood cell depth increases with an increase in brood comb thickness. The cell volume reduces with the hexagonal cell's decreasing inner circumference side length, and diameter. A smaller cell volume leads to a decrease in the birth weight and body size of the worker, in addition, the Chinese honey bee has gnawed off the comb cells that have been cultivated for eight generations. This study suggests that the combs of Chinese honey bees should be replaced after eight generations to improve colony strength and production performance.