34 BULLETIN" 1349, IT. S. DEPARTMENT OF AGRICULTURE 



presence of bees too young for field work does not in itself induce 

 swarming unless there is such an excess of young bees beyond those 

 required for hive duties as to interfere with the routine of the colony. 



Any appreciable excess of young bees arises, not for the sake of 

 intensifying the natural swarming impulse, but rather as a result of 

 other factors. Such an excess is bound to occur if conditions within 

 the colony prevent a large number of young bees from performing 

 the functions of their normal life cycle. This would be the case 

 whenever brood-rearing activity reached the limit of cells available 

 at a period when the brood-rearing area would have been further 

 enlarged if more cells had been at hand, or if under similar conditions 

 brood rearing were restricted through a reduction in the number of 

 cells available for brood by their use for incoming nectar or pollen. 

 The egg-laying rate being then reduced to a noticeable extent for 

 several days, there would eventually be fewer larvae to care for, fewer 

 cells to clean out, fewer cells to be sealed over, and a diminution in 

 all of the activities incident to a period of intense brood rearing. In 

 consequence, since such duties are usually performed by young bees, 

 there would be many of the latter out of a job, so to speak. 



Throughout the observations in this research it has been noted 

 that all colonies, strong as well as weak, tend to crowd incoming 

 nectar not only around the border of the brood nest but even within 

 the brood area itself whenever an empty cell is found. Such a ten- 

 dency has long been recognized. Consequently, if during a honey 

 flow many cells within the brood area proper become available for 

 depositing incoming nectar through the emergence of large numbers 

 of young bees, the queen may be restricted suddenly in her activity, 

 as happened in 1921 to the queen in colony No. 4. Under these 

 conditions there would result an excess of young bees. Whether 

 this excess would be large enough to induce swarming would depend 

 on the degree and duration of restriction of the queen's activities. 

 In the case of colony No. 4 and the others the restriction was never 

 of long duration. It has often been observed that just prior to 

 swarming the queen almost entirely ceases egg laying, so that all 

 unsealed brood disappears. Such a condition is simply the natural 

 result if any large number of brood cells have been used for another 

 purpose. Not only may the number of cells available for egg laying 

 become insufficient through diversion to use for incoming nectar 

 and pollen, but even without any reduction in number by these 

 causes there will be too few whenever brood rearing itself reaches the 

 limit of cells available in the hive. During a period of normal 

 seasonal increase in brood-rearing activity, idle field bees may at 

 times cause a congestion within the hive which apparently inter- 

 feres with brood rearing. Any of these conditions may arise 

 independently of any honey flow, and would tend to explain the fact 

 that swarming is not always correlated with a honey flow. 



In the colonies under discussion a swarming impulse was doubtless 

 restrained by the fact that at no time was any colony crowded for 

 room long enough to cause a serious break in the continuity of brood 

 rearing at a time when the tendency toward brood-rearing activity 

 was strong. Whenever any queen became restricted in any particular 

 hive body during a period favorable to continued, heightened brood- 

 rearing activity, she was able to migrate to a more suitable region 

 within the hive. Through this ability to transfer her activity else- 



