THE BROOD-BEARING CYCLE OE THE HONEYBEE 7 



conducive factors, brood-rearing activity is prevalent, and that in 

 the remaining portion of the year brood-rearing activity is suspended. 

 The annual brood-rearing cycle may therefore be divided into two 

 parts: (1) a period of seasonal activity and (2) a period of seasonal 

 suspension. The period of seasonal brood-rearing activity, or the 

 "active season," takes place, roughly speaking, during the summer; 

 the period of seasonal suspension of brood rearing, here called the 

 "inactive season," occurs in winter. 



SEASONAL ACTIVITY 



At the end of the inactive season, marked normally by the first 

 incoming nectar or pollen, brood rearing is resumed and may proceed 

 to a certain maximum in the fore part of the active season at a rate 

 which is often strikingly noticeable. Brood-rearing activity during 

 the remainder of the active season, up to the period of final decline, 

 varies widely with geographical location or climatic conditions. In 

 some regions it is maintained at a uniformly high rate throughout; 

 in other regions it is broken in continuity by an interval of partial 

 suspension. In still other regions there is a gradation between these 

 two extreme types of seasonal brood-rearing activity. The final 

 decline is either abrupt or gradual, depending also on geographical 

 location. Regardless of geographical location or climatic conditions, 

 the period of seasonal activity may be divided into the three following 

 phases: (1) A period of initial expansion, (2) a major period, (3) a 

 period of final contraction. It is not always possible to draw a sharp 

 line of demarcation between these three seasonal phases of brood- 

 rearing activity, because external environment, such as weather or 

 incoming nectar and pollen, often causes the end of one seasonal 

 phase to become so merged with the beginning of the next that the 

 initial influence of the succeeding phase can not easily be detected. 



PERIOD OF INITIAL EXPANSION 



The initial expansion covers that period of the active season 

 immediately following the inactive season, in which brood-rearing 

 activity is normally resumed and is continued in spite of conditions 

 which if occurring later in the season would tend to check brood 

 rearing. It should be pointed out that the beginning of brood rearing 

 here discussed is that caused by the incoming of the first nectar or 

 pollen and does not apply to abnormal brood rearing during the 

 inactive season, which will be discussed later. At no other time in 

 the year does the tendency to rear brood seem so persistent as during 

 this initial phase, except possibly when a colony has just swarmed 

 or when a queen is beginning to lay for the first time. Although the 

 rate of increase in brood-rearing activity may be greatly accelerated 

 during the period of initial seasonal expansion by incoming nectar or 

 pollen, the fact that such an expansion continues after resumption 

 of brood rearing, even with no incoming nectar or pollen, indicates 

 that this phase is purely seasonal and needs only the approach of 

 spring to cause its appearance. 



Since this expansion in the spring is a seasonal phenomenon, and 

 is hound to occur, the colony which will gain the most rapidly in 

 population in the spring is the one possessing the largest number of 

 factors favorable for brood rearing. It becomes readily apparent, 



