The size (e.g. length, width and volume) and the weight of eggs laid by A. mellifera caucasica queens (Qs) and laying workers (LWs) in both worker cells (WC) and in drone cells (DC) were compared. All measurements were taken at 3 different embryonic developmental periods (at 0–6 h, 18–24 h and 54–60 h after oviposition). The results showed that the size and weight of fertilized (in WC) and unfertilized (in DC) eggs laid by queens did not differ significantly. However, eggs from laying workers were 2.8% longer and 10.7% wider, they had as much as 22.2% larger volume and they were 22.3% heavier compared to eggs laid by queens. Thus, eggs from A. m. caucasica laying workers were larger and heavier than from queens. Significant decrease of size and weight occurred during embryonic development. Shortly before hatching, eggs from queens and workers lost 5.4% and 6.4% of their length, 8.9% and 9.1% of their width, 16.4% and 16.9% of their volume and 28.1% and 24.2% of their weight, respectively. Eggs laid by queens lost 3.9% more weight than eggs laid by workers, and shortly before hatching their density (ratio of weight/volume) was 86.3% of the initial in eggs from queens and 91.7% in eggs from laying workers. The decrease of the density indicates that the ratio of the lighter fat must have increased in relationship to the other egg components. The larger eggs from laying workers in comparison to eggs from queens may be the result of lower number of ovarioles in workers (2–12) than in queens (160–180).
honey bee, Apis mellifera caucasica, laying workers, queen, egg weight, egg size, drone comb cells