6 BULLETIN 1349, U. S. DEPARTMENT OP AGRICULTURE 



minimum, although in any event, in the cooler weather of spring or 

 fall, there are few frames containing sealed brood. The hive being 

 open for so little time, danger from robbing is also reduced, and the 

 normal activity of the colony is disturbed to a far less degree than 

 is the case in any other method of brood-area determination so far 

 employed. The great speed with which the work can be accomplished 

 adapts this method to investigations on a large scale. In the first 

 two years of this work more than 18,000 pictures were thus taken. 



DEFINITIONS 



The term "brood nest" as used in this bulletin applies to the space 

 occupied by brood, regardless of the number of hive bodies in which 

 brood is found. The term " brood area" is similarly applied. The 

 term " super" is' used for the hive bodies which are placed above 

 the second hive body to give additional room for colony activity, 

 the lower two hive bodies being those which remain with the colony 

 permanently, summer and winter. The hive bodies are of uniform 

 size, regardless of purpose. Brood could be reared in the supers of 

 hives in which no restriction was placed on the movements of the 

 queen by a queen excluder. In the apiary of the Bureau of En- 

 tomology, where this work was done, the colonies are arranged in 

 groups of four for convenience in putting them into packing cases 

 for winter, and such groups are referred to as packing-case groups. 

 The term "quadruple packing case" refers, of course, to the fact 

 that each of the packing cases used is capable of containing four 

 colonies. "Nectar flow" and "honey flow" are used synonymously 

 to cover those periods in which nectar available for the honeybee is 

 secreted freely. "Pollen yield" refers to the gathering of pollen in 

 large quantities. The term "natural requeening" is used in this 

 bulletin for the requeening of colonies in which it is impossible to 

 determine whether the old queen was lost through natural superse- 

 dure or whether she was accidentally killed while the colony was 

 being handled. Where artificial requeening was practiced, as by 

 the killing of the old queen and the giving of a queen or queen cell, 

 the period of queenlessness is less than in natural requeening. 



ANNUAL BROOD-REARING CYCLE 



Common recognition of certain factors underlying brood rearing 

 has given rise to different apiary practices. For example, it has long 

 been believed, regardless of geographical conditions, that a honey 

 flow greatly stimulates egg laying. This is attested by such apiary 

 practices as dequeening during a honey flow, removing brood, and 

 the like. Although apiary practice has contributed much to a 

 knowledge of brood rearing, it has not as yet furnished a clear, 

 definite understanding of all of the factors causing an increase or 

 decrease of brood-rearing activity. For instance, it has not been 

 established as a fact that brood-rearing activity increases in a uni- 

 form and regular manner during the beginning of the active season, 

 nor that irregularities may then occur. In short, each seasonal 

 phase of brood rearing presents problems, not fuUy solved as yet, 

 which are of vital importance in beekeeping practice. 



It is a matter of common apiary experience that during a certain 

 portion of the year, depending on weather, nectar flows, and other 



