UNITED STATES DEPARTMENT OF AGRICULTURE 
DEPARTMENT BULLETIN No. 1349 
Washington, D. C. ▼ September, 1925 
THE BROOD-REARING CYCLE OF THE HONEYBEE 
By W. J. Nolan, Associate Apiculturist , Division of Bee Culture Investigations, 
Bureau of Entomolgy 
CONTENTS 
Page 
Introduction 1 
Method 4 
Annual brood-rearing cycle 6 
Description of the colonies used in 1921 12 
Seasonal characteristics of 1921 .- 13 
Brood rearing of a typical colony for two suc- 
cessive seasons 14 
General observations on the remaining colonies. 16 
General discussion of the records for 1921 25 
Observations in 1920 27 
Page 
Migrations of the queen within the hive 30 
Compactness of brood nest 1 32 
Time relation of brood rearing to nectar gath- 
ered.. 33 
Egg laying 35 
Conclusions 36 
Literature cited 37 
Tables . 38 
Graphs 44 
INTRODUCTION 
In previous work of the Bureau of Entomology emphasis has been 
placed on the conditions necessary for the proper wintering of bees, 
in order that colony population and energy may be conserved to the 
utmost during the period when no brood is reared by normal colonies. 
It is evident, however, that merely wintering the bees in the best 
possible condition will not in itself guarantee that the colony will at 
the right moment have the proper strength and composition for 
gathering a maximum honey crop. Nevertheless, if, through proper 
wintering, the strength of the colony has been adequately conserved, 
the resumption of brood rearing in the spring may take place at the 
proper time and the amount of brood reared may increase at a remark- 
able rate, since the ability of the colony will not have been impaired 
through excessive work during the winter. It is appropriate, there- 
fore, that the investigation of wintering conditions should be followed 
by an investigation of the factors which modify brood-rearing activity, 
more especially those which are under the control of the beekeeper. 
Since normally a worker bee, before going to the field, spends the 
first two or three weeks of its life in duties within the hive, the quantity 
of nectar gathered by any colony depends not merely on the total 
number of bees in the colony during a honey flow, but on the number 
included within that total which represents bees of proper age to serve 
as nectar gatherers. In order to have the largest possible number of 
field bees at the proper moment, therefore, the highest daily rate of 
bees emerging from the brood cells during any given season should 
D — 25t— Bull. 1349 1 
