| A Biometrical Study
of the Influence of Size of Brood Cell Upon the Size and Variability
of the Honeybee (Apis mellifera L.) by Roy A. Grout, 1931 |
| REVIEW OF LITERATURE 2. Age of comb controversy. The controversy concerning the age of comb and its possible effect upon the size of the emerging brood dates back at least to the middle of the 19th century. Quinby (54), in his book published in 1865, states that old combs are good for a period of 10 to 15 years due to the fact that while the bottoms of the brood cells are filled with cast-off pupa skins, the cocoon, excrement and varnishing resulting from each generation, the side walls are only slightly thickened and the bees lengthen them to compensate for the thickening at the midrib. It is Quinby's opinion that the cells are unquestionably built larger than necessary. Dadant (18), Miller (47), Root (60), and others took part in this controversy and all believed that the age of the comb did not materially affect the size of the emerging bees. This controversy first originated in Europe and then spread to our country. Riedenbach (57), of Germany, showed by filling new and old combs with water that although the midrib is noticeably thickened by the emerging generations, the cell volume is not greatly changed due to the lengthening of the side walls. Ludwig (40) coincided with Riedenbach in his contentions and by actual measurement showed that there is no difference existing in the general roominess of brood cells of old and new combs. Brunnich (10) believed that the danger of the cells of old brood combs becoming smaller with age was not as great as many beekeepers believed. Rambaldi (55) reports that in 1927 he had kept Palestine and North African bees on combs built from Root foundation having 856 cell bases per square decimeter during hundreds of generations and had noticed no effect upon the size of the bees. In Russia the study of the effect of old combs upon the size of the emerging bees was first attempted by Tuenin (68), who showed, by weighing the emerging bees from combs from which 2, 6, 28, and 38 generations had emerged previous to the experiment, that the weight decreased with the number of generations from 0.12612 gms. to 0.10695 gms. and that the cell diameter decreased from 5.262 mm. to 4.99 mm. He concluded that as the number of generations that emerged from the cells became more numerous, the resulting bees became smaller as indicated by the weight of the emerging bees. Michailov (44) continued this study by measuring 5 physical characters of the skeleton, namely, length of proboscis, length of the right fore wing, width of the same wing, the summation of the widths of the 3rd and 4th tergites, and the number of hooks on the right hind wing. He showed that the size of the cells as reduced by the emerging generations (5.89% in the diameter due to 16 and 18 generations) is accompanied by a significant reduction in the size of bees. By reducing the cell diameter by approximately 3% there was no significant reduction in the body size of the emerging bees. the depth of the cell showed no influence upon the size of the bee. He concluded that, in order to enlarge the bee by using artificial foundation, we should pay particular attention to the diameter of the cell and not to the depth of the cell. According to Rupp (51), who based his conclusions on the work of Michailov, a comb is too old to use for brood rearing when it is three years old based upon the figure of 5 to 6 generations per year. |