368 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 15 



are favorable, replanting may be resorted to when the' first planting 

 becomes badly blighted in the early part of the season. 



Systematic records of this nature should be continued in years when 

 the beet leafhoppers are at their maximirm in nirmber, and through the 

 interval between outbreaks so that all conditions can be recorded. 

 Better decisions on crop prospects with reference to curly leaf and the 

 nmnber of beet leafhoppers can be rendered early in the season with 

 more data available. 



THE EFFECT OF ACTIVITY ON THE LENGTH OF LIFE OF 



HONEYBEES 



Bv E. F. Phillips, Bureau of Entomology 



That honeybees live longer when they are least active has been known 

 for many years. This is especially evident from the fact that during 

 the heavy honey -flow the worker bees live about six weeks while during 

 the winter they may live four times as long. It may be that this differ- 

 ence is in some degree associated with certain physiological conditions 

 which need not be discussed at this time, but it seems clear that the 

 chief difference is in the amount of work which they are called upon to 

 do. It has for a nimiber of years been believed that the greater the 

 activity of the bees, the shorter their term of life. 



In connection with some experiments to determine the availability 

 of various carbohydrates as food for worker bees, it was noted that the 

 bees used as checks on the experiments, and which were given no food 

 whatever, lived for different periods, taking an average of the daily 

 death rate. In the first series of experiments (August 1914) the bees 

 without food averaged 1 .74 ± 0.0377 days. In the second series (Septem- 

 ber 1914) the average for unfed bees was 4.34 ±0.0662 days. For the 

 third series (September 1919) the average was 1.375 days. For the 

 fourth series (May 1922) three lots of bees without food were put under 

 different conditions, and it is the purpose of this note to discuss these 

 results in detail. In a fifth series (May 1922) the average for the bees 

 without food was 2.4164±0.0216 days. 



In the fourth series three lots of worker bees were placed in wire-cloth 

 and wood cages and each cage was provided with a water bottle but the 

 bees were given no food after the beginning of the experiment. The 

 small nimiber of drones in each cage is omitted from the following figures : — 

 Lot No. 1 (274 bees) was placed in a dark room in the basement of the 

 laboratory, light being introduced into the room once daily when the 



