GLEANINGS IN BEE CULTURE 



It is a little difficult to review or give a 

 condensed summary of a work of this kind ; 

 and we would, therefore, suggest that the 

 reader who desires to get more direct in- 

 formation send to the Superintendent of 

 Documents, Government Piinting-offlce. 

 Washington, D. C, for Bulletin 93 of the 

 Department of Agriculture, by Phillips and 

 Demuth, inclosing five cents. Stamps will 

 not be accepted. 



For the present information of our read- 

 ers we will endeavor to give a summary of 

 the observations and conclusions set forth 

 in this bulletin. 



Let us first consider the outside-wintered 

 colony which had 19 electric thermometers, 

 with connections to the observation room 

 below. Bees were placed on tlip roof early 

 in November. From then on until along in 

 March the inside and outside temperatures 

 were taken. It was learned that the tem- 

 perature within the cluster is far from be- 

 ing uniform, as is generally supposed by 

 beekeepers. " At the temperature at which 

 other insects become le^s active (begin 

 hibernation) the honej'bee becomes more 

 active, and generates heat — in some cases 

 until the temperature within the cluster is 

 as high as that of the brood-nest in sum- 

 mer." During the fore part of the read- 

 ings in November and December the inter- 

 ral temperature of the cluster of this out- 

 side colony had a tendency to drop as the 

 outside temperature went down until it 

 reached 57 F. At that jDoint the reaction 

 took place; that is, the generation of heat 

 began, and from this point it began to rise 

 in spite of the fact that the outside tem- 

 i:erature continued to drop. The cluster 

 heat continued to lise until the center of it 

 registered nearly 90 degrees. After the 

 coldest outside temperature was reached, 

 the outer air began to get warmer, and 

 simultaneously the temperature of the clus- 

 ter began to sag. 



We might remark, in passing, that Dr. 

 Gates tried these experiments at an earlier 

 period, as reported in Bulletin No. 96 else- 

 where, and discovered a similar inverse 

 ratio; but he did not find the exact jDoint 

 when the colony temperature ceased to drop 

 with tliat of the outside. Dr. Phillips and 

 Mr. Demuth learned that this point is 57 

 F. When the colony is Avithoul brood, and 

 the bees are not flying, the bees generate 

 practically no heat until the coolest point 

 among the bees reaches a tempei'ature of 57 

 F. " At this point the bees begin to form 

 a comi^act cluster; and if the temperature 

 of the air surrounding them continues to 

 drop, they begin to generate heat." Be- 

 tween 57 and 69 F. the bees do not do much 



in the way of heat generation. Apparent- 

 ly, then, it will be desirable to have the 

 surrounding temperature at such a point 

 that the internal temperature of the cluster 

 will not go below 57 nor above 69; but, as 

 we shall afterward show, the (|uestion of 

 food and syrup are additional factors to be 

 considered. 



But there are some other data given in 

 this bulletin that go to show that bees have 

 the power of raising the temperature of 

 the cluster; but apparently conditions must 

 be right to do this. We Avill come back to 

 this point a little further on. 



We will now turn our attention to the 

 colonies, or one of them at least, in the 

 constant-temperature room, whei'e the mer- 

 cury was kept at about 42 or Id degrees F. 

 " This temperature was chosen as being 

 nearly the one generally consiJeied best by 

 beekeepers." There were two colonies — one 

 fed on honey stores and another on an 

 inferior grade of honey-dew honey, that are 

 particularly mentioned in the bulletin. Col- 

 ony No. 1, fed on honey stores, was in a 

 constant-temperature room for 163 days, 

 during which readings were taken hourly. 

 At first the internal temperaiure of the 

 cluster according to the chart hovered 

 around 64 and 68. It rose gradually clear 

 through the winter. The colony fed on 

 honey-dew stores showed a higher temper- 

 ature at the beginning; when up to about 

 76 F. it began to take a sharp rise, going 

 up to 91 above, and on Nov. 23d the 

 temperature began to show a sharp drop. 

 the line running doAvn as low as 48 on Dec. 

 10, when the colony died. Clearly the poor 

 food caused uneasiness by reason of the 

 accumulation of fecal matter that the bees 

 could not digest, and this uneasiness caused 

 activity, and activity called for a greater 

 consumiDtion of stores. The one condition 

 operated against the other, finally ending 

 in the destruction of the colony. The other 

 liive fed on good honey pursued its normal 

 course through the season. 



It is interesting to observe 'hat tlie nor- 

 mal temperature of the cluster of the colo- 

 ny fed on good stores only gradually in- 

 creased, and this increase was doubtless due 

 to the slight accumulation of feces. This 

 accumulation was markedly less than that 

 in the case of the colony on honey-dew 

 stores, not because the bees becpme uneasy, 

 but in proportion as the f^ces increased, 

 the activity and temperature of the colony 

 increased. This increase was not enough 

 liowever, to cause the death of the colony, 

 but a slight reduction in the force in the 

 spring. These observations explain the 



