68 



FOURTEENTH ANNUAL REPORT OF THE 



know that the winter losses are con- 

 siderable but it is nevertheless a fact 

 that bee-keepers often fail to realize 

 in full the magnitude of the winter 

 loss, in an average or even in a mild 

 winter. The season of 1911-12 was 

 the most recent case that we have ex- 

 perienced of a winter accompanied by 

 severe losses. The summer of 1911 was 

 a poor season for most localities in the 

 north and most colonies were weaker 

 than usual all summer. They went in- 

 to winter weak, short of stores and 

 with too many old bees. The winter 

 was exceptionally severe and many 

 colonies were not in condition to ex- 

 pend the energy necessary to maintain 

 life and as a result the loss by the 

 death of colonies was over 50 per cent 

 in many apiaries.* If the bees had been 

 in condition to obtain the bountiful 

 crop of 1912, that year would have been 

 a banner year in bee-keeping but there 

 were not enough bees. 



Similarly in 1909 there was a dearth 

 of nectar but an abundance of honey- 

 dew in many localities, causing enor- 

 mous losses in the following winter. 

 The W'inter of 1903-4 was another of 

 heavy losses while that of 1884-85 was 

 one of the worst ever experienced by 

 American bee-keepers. 



It is of course evident that good bee- 

 keepers lose less colonies than those 

 who are uninformed, but even the good 

 bee-keeper loses sometimes. An esti- 

 mate of 10 per cent for the average 

 annual loss is probably conservative 

 and it speaks well for bee-keeping as 

 an occupation that American bee-keep- 

 ers can sustain such a loss year after 

 year without destroying the industry. 

 Looking, then, at the other side of the 

 picture it is clear that if this losg can 

 be prevented bee-keeping ought to ad- 

 vance rapidly to its rightful place in 

 American agriculture. 



From the experience and observa-' 

 tions of bee-keeping we now know con- 

 siderable about wintering, and our in- 

 formation is increasing constantly. 

 There are two facts concerning this 

 information to which attention should 

 be directed. First, many of the very 

 best observations have appeared in the 

 bee journals but are now practically 

 forgotten because bee-keeperg are often 

 not careful enough to keep complete 

 flies of their journals and to consult 

 them frequently. A bee journal is not 

 altogether a newspaper but should be 

 considered as a permanent record of 



the good things observed. The other 

 consideration is that the results have 

 been obtained at enormous cost since 

 they are records in the main only of 

 gross results. A bee-keeper tries a 

 certain method of wintering and neces- 

 sarily gauges his success by what is 

 left the following spring. With the 

 facilities of the apiary detailed observa- 

 tions as to the daily activities and re- 

 quirements of the bees are impossible 

 and consequently our knowledge of 

 wintering ig based largely on commer-^ 

 cial experience but is lacking in facts 

 concerning the detailed needs of the 

 bees. 



In the present discussion of this sub- 

 ject it is proposed to depart somewhat 

 from the usual methods in discussing 

 the wintering problem and to record 

 some of the things that bees do in win- 

 ter as well as to explain some of the 

 physical phenomena observed. In do- 

 ing so I shall draw on the results pub- 

 lished by Mr. Demuth and myself con- 

 cerning our work of the past two years. 

 While I am having the pleasure of at- 

 tending this meeting Mr. Demuth is 

 back at the laboratory making more 

 observations, although rightfully we 

 should read this paper as a-^uet. 



The Source of Heat in the Colony. 



It is a well known fact tnat bees gen- 

 erate heat during cold weather, so that 

 the temperature of the cluster never 

 drops very low. The lowest tempera- 

 ture that we have foumi is 57° F. 

 In order to see what the bees do during 

 this peribd of heat production, we de- 

 Vised a special outfit so that ^e could 

 see the inside of the cluster. A colony 

 in winter forms a compact, approxi- 

 mately spherical cluster and on the out- 

 side of the cluster there is nothing that 

 one can see that suggests the heavy 

 heat production that must take place. 

 However, a narrow hive was provided 

 with double glass sides and top with 

 an air space between the sheets oe glass 

 to act as an insulation. The stores 

 were then so arranged that the only 

 space available for the cluster was next 

 to the glass on one side. In ythe out- 

 side space were placed a niimber of 

 the electrical thermometers which we 

 used and which are briefly described in 

 Bulletin No. 93 of the Department of 

 Agriculture, to which those interested 

 are referred. In the space provided 

 there was not room for a spherical clus- 

 ter, so the bees formed a hemisphere. 



