2 BULLETIN 1339, U. S, DEPARTMENT OF AGRICULTURE 



the colonies so as to induce the bees to expend their energy in gath- 

 ering, which, as every experienced beekeeper knows, means the con- 

 trol of swarming and any other instinctive activity which might tend 

 to reduce the manifestation of the gathering instinct. The last two 

 factors of those above mentioned have to a considerable degree been 

 neglected, doubtless because they are outside the control of the bee- 

 keeper in any given location. Since the honey crop is so intimately 

 connected with these factors, however, it is unwise to neglect them. 

 There are extensive records and lists of the plants which furnish nee • 

 tar in quantities sufficient to make beekeeping profitable in the var- 

 ious parts of the country, and there are certain results of botanical 

 investigations which bear on this subject, but as a rule these results 

 have not been part of the beekeeping literature. Almost no atten- 

 tion has been paid to the effect of weather factors on the gathering 

 of the crop. 



The purpose of this bulletin is to present information on the rela- 

 tionship existing between changes in the weight of a colony of bees 

 during a honey flow and the prevailing weather conditions, based on 

 data obtained at the Bee Culture Laboratory, Somerset, Md., from 

 February to November, 1922, and for the month of May, 1923. 

 The major problem during this time was an intensive study of colony 

 temperatures, but this experiment necessitated the recording of 

 changes in the weight of at least one colony of bees hourly throughout 

 the day and night for long consecutive periods. At the conclusion 

 of the experiment a hasty survey of these changes immediately re- 

 vealed an abundance of interesting data which seemed to throw con- 

 siderable light upon the relationship of changes in hive weights to 

 outside conditions. Although the data herein recorded on the fac- 

 tors influencing changes in weight are not as complete as they should 

 be to carry such a problem to a final conclusion, the subject is here 

 presented from the material available in the hope that it will serve 

 as a stimulus to investigators in different great honey-producing 

 areas to study the relationship of weather to honey production. A 

 problem like this can not be solved without such comparative data. 

 Information of this sort covering the principal honey-producing sec- 

 tions of the United States would be of inestimable value in the fur- 

 therance of beekeeping. A knowledge of existing honey flora and a 

 correlation of weather conditions with bee behavior should help the 

 prospective beekeeper in choosing the best beekeeping locality. At 

 the present time there is no method of predicting whether a locality 

 will prove profitable to the beekeeper except by the results obtained 

 by other beekeepers. It would be well to know just why certain 

 plants produce nectar in one locality and not in another, and, more 

 important still, to discover if possible the laws underlying the rela- 

 tionship between bees, nectar-producing plants, and weather condi- 

 tions as they influence the results of the beekeeper, and to determine, 

 if possible, which are the most important factors upon which the 

 honey crop depends. 



In this discussion the results of the relationship of bees and nectar- 

 producing plants are shown either as surplus honey or as increase 

 in the weight of the colony. The two results are inseparable as far 

 as the present work is concerned. No effort was made to study 

 plant behavior and bee behavior as separate subjects, but the results 



