514 IOWA DEPARTMENT OF AGRICULTURE 



more heat to be produced evidently increased much more rapidly. As 

 stated previously, honeydew honey is a poor food for winter and is so 

 recognized. It contains the same sugars as honey, but contains in addition 

 a considerable amount of dextrin, the particular lot fed to colony 3 con- 

 taining 4.55 per cent while good honeys contain only a fraction of 1 per 

 cent. Prom the evidence at hand it appears that dextrin can not be 

 digested by bees and, whether or not this is the explanation, honeydew 

 honey causes a rapid accumulation of feces which usually results in the 

 condition known as dysentery, in bad cases of which the feces are voided 

 in the hive. In the case of Colony 3 the whole hive inside and out, as 

 well as the frames and combs, were spotted badly, the inside of the hive 

 being practically covered. Even with fine honey stores such a spotting 

 is usually noticed after a prolonged confinement, especially in severe 

 weather (or during brood rearing). It therefore appears that the ac- 

 cumulation of- feces acts as an irritant, causing the bees to become more 

 active and consequently to maintain a higher temperature. We are there- 

 fore justified in believing that the cause of poor wintering on honeydew 

 honey is due to excessive activity, resulting in the bees wearing them- 

 selves out and ultimately in the death of the colony. In the case of col- 

 onies on good stores the feces accumulate more slowly and the excess 

 activity is not so marked and is induced more gradually. The accumula- 

 tion of feces due to confinement causes increased activity and this in turn 

 is the cause of excessive heat production, resulting in a reduction in the 

 vitality of the bees. 



It therefore follows that excessive activity causes the consumption of 

 more food, resulting in turn in more feces, so that colonies on poor stores 

 are traveling in a vicious circle, which, if the feces can not be discharged, 

 results in the death of the colony. 



While the activity of the cluster is greater at some times than at others, 

 there are not, as has been held, regular intervals of activity at which the 

 colony rouses itself to take food. At no time is a colony kept at a room 

 temperature of 45° P. or less in a condition which can be characterized as 

 inactive. Presumably the reported "intervals of activity" have occurred 

 when the colony made a noise due to disturbance by the beekeeper. 



The bees in Colony 3 were compelled to work constantly to maintain 

 so high a cluster temperature. In fact, they did more work than colonies 

 wintered in the open air. Keeping these bees in a cellar protected them 

 from low outside temperatures, but the lack of opportunity for a normal 

 ejection of feces caused a condition more serious than extreme cold 

 weather. We seem to have here an explanation of the fact, often observed 

 by beekeepers, that some colonies wintered in the cellar are in worse con- 

 dition in the spring than colonies that are exposed to severe cold. Poor 

 food is evidently a more serious handicap than low temperature. 



HUMIDITY IN WINTER. 



This subject is one concerning which less definite information is avail- 

 able, although it is one which has been much discussed by beekeepers. 

 One of the chief difficulties seems to be a lack of information concerning 

 the interrelationship of temperature and relative humidity and it may be 

 well to make some of these points clear. 



