﻿14 BULLETIN 1364, U. S. DEPAKTMENT OF AGEICULTURE 



weighed on the chemical balances hourly during each day. To ascer- 

 tain the increase, also consisting largely of nectar, of an undisturbed 

 colony, a hive of bees was kept on the scales at Winchester in 1916, 

 and hourly readings were made of the weight of the entire hive and 

 contents. In 1916, at both Winchester and Fennville, the hives and 

 combs of the colonies weighed daily were kept together in sets in 

 order to obtain the daily gain or loss in weight. Furthermore, 

 observations were made hourly during the day on the amount of 

 visible nectar in the blossoms and the number of bees visiting them. 



To determine the gain or loss of both old and emerging bees, two 

 colonies (Nos. 17 and 18) in the Lupton orchard were weighed on 

 the evenings of April 29, May 4, and May 11, after the bees had all 

 returned to the hives. The weight of the bees, separate from the 

 hive and combs, was found by a method similar to that used in the 

 daily weight determinations previously described, but in this case 

 the maturing brood was not removed. 



Four dead-bee traps (ISTos. 7 to 10) were installed in the Cooper 

 apiary, four (Nos. 11 to 14) in the Miller apiary, and two (Nos. 15 

 and 16) in the Lupton apiary. 



Data on the local temperature and humidity prevailing during 

 the experiments were obtained by means of a thermograph, hygro- 

 graph, maximum and minimum thermometers, and a sling psychro- 

 meter. Observations were also made on the direction and velocity 

 of the wind and character of day. 



DAILY OBSERVATIONS 



In 1915, at Winchester, abnormal weather conditions greatly 

 hastened the development of the fruit blossoms. No weight records 

 were obtained previous to the application of the spray mixture. 

 On the morning of April 30 the first weight record (on the platform 

 scales) was obtained, and spraying was begun in a large orchard 100 

 yards distant from the bees weighed. On April 29, when about 60 

 per cent of the petals had fallen, the bees worked freely on the 

 blossoms; on April 30, after a strong wind and when 95 per cent 

 or more of the petals had dropped, the bees worked less freely ; and 

 from this date till the end of the experiments on May 8 very little 

 nectar was gathered from the sprayed blossoms. 



On April 30 the total weight of the bees in the six hives weighed 

 was 215 ounces (Table 2) ; but on May 8, eight days after the spray- 

 ing was begun, the bees weighed 84 ounces less. The average daily 

 loss was therefore 10.5 ounces, or 4.88 per cent of the initial weight. 

 The loss in ounces for each of the several days from April 30 to May 

 8, inclusive, beginning with May 1, was 40, 15, 7, 5.5, 7, 1.5, 0.5, and 

 7.5 ounces. The first daily loss was exceedingly large; the others 

 relatively small. 



