10 BULLETIN 685, U. S. DEPARTMENT OF AGEICULTUBE. 

 Table II. — Honeybees: Per cent of total swarming, by months — Contd. 



INCREASE BY SWARMING. 



The net changes in nimiber of colonies from year to year 

 is the balance between the increase by swarming, natural and 

 artificial, and the losses. The annual primary increase by 

 swarming must, to offset the losses, average between 15 and 

 20 per cent of the number of colonies, not counting the 

 swarms that escape and estabhsh themselves in hollow trees, 

 rock cavities, etc. The number so escaping must be quite 

 large, but can not be determined. Most of the increase is 

 by natural swarming, but as this often reduces the production 

 of surplus honey, there is an increasing tendency among bee- 

 keepers, amounting to a practice among a large part of those 

 who make this a regular business, to prevent natural swarm- 

 ing during the main nectar flow, in order that the bees may 

 devote all of their energies to the gathering of honey. Pro- 

 vision for increase in number of colonies, if desired, is made 



