512 IOWA DEPARTMENT OF AGRICULTURE 



mum of 13° P. at 9 p. m., March 20. At no time, however, did any of the 

 thermometers in the hive record a temperature below 33° F. Here it re- 

 mained constant within 0.1° F. for about six hours, during which time 

 the cluster temperature varied between 86.5° and 89.5° F. (a difference 

 between the room and the cluster temperatures of 73° to 76° F.) The 

 brine was turned on full and the room cooled rapidly, reaching the mini- 

 24, when it reached a temperature of 44.5° F. During this warming the 

 cluster cooled until at the close it was varying between 72° and 79° F. 



As stated above, the colony was now (9 a. m., March 24) removed for a 

 flight and put back the same day at 7 p. m. In the meantime the room 

 was cooled to 33° F. When the bees were put back into the room the tem- 

 perature of the entire inside of the hive showed great variation and nat- 

 urally an increase due to the warming up while out of doors and to the 

 activities of a good flight. The points outside the cluster dropped rapidly, 

 but it was midnight, March 25 (31 hours), before the curves of tempera- 

 ture again appeared normal. The room was slowly warmed to 63.2° F. 

 at 6:30 p. m., March 26, and then slightly cooled to 54° F. at 6 a. m., 

 March 27, and again warmed to 58.5° at the close of the series, 4 p. m., 

 March 28. After the flight the temperature of the cluster never dropped 

 below 89.5° F., and the highest temperature reached was over 95° F. (soon 

 after the flight). Thermometer 6 remained high, but thermometer 2, 

 which had previously been high, now approached the other thermometers, 

 probably due to a rapid loss of bees and to a decrease in the number of 

 bees during the flight. It must be recalled that these bees had been con- 

 fined for an abnormally long time and were subjected to treatment which 

 is at least unusual. After this colony was taken from the room for the 

 last time it was found that thermometer 6 was over a patch of larvae, 

 and, estimating as accurately as possible, the eggs from which these 

 hatched must have been laid at the time when the room was coldest 

 (March 20-21) and when the cluster temperature was at its highest point. 

 There had been no brood previously according to the temperature records 

 as compared with those of this colony earlier and with those of other 

 colonies, nor was there much evidence of increased heat production due 

 to the presence of brood until after the flight. Probably no extra heat 

 was produced for the eggs, and possibly the hatching of the eggs was 

 somewhat delayed by the low outer temperature. The effects on the 

 cluster temperature which might be expected from a flight, in relieving 

 the accumulation of feces, were not observed, because brood rearing had 

 been begun. 



Colony No. 3 was placed in the constant temperature room October 12, 

 1912, after a good flight, and readings were begun on Monday, the 14th. 

 In all, 2,165 temperature records were made on Colony 3. The stores 

 provided this colony consisted of honeydew honey, which was gathered in 

 the department apiary and which, since it granulated almost at once, had 

 been removed by melting up the combs which contained it. After this 

 operation it remained liquid. During the summer of 1912 some of this 

 honeydew honey was fed to a colony in the open, during a dearth of nectar, 

 and was stored in new combs above the brood chamber, in which no cells 



