﻿22 BULLETIN 1364, U. S. DEPAETMENT OF AGEICULTUEE 



ounce of bees on the first date contained 292.9 bees; on the second, 

 23Y.2 bees; and on the third, 258.2 bees. The general average per 

 bee of the 1,170 individual bees weighed in 52 samples at Winchester 

 in 1915 and 1916 and at Fennville and Drummond is 0.1099 gram. 

 Using this value, an ounce of bees is found to contain on an average 

 258 individual bees, or a pound would contain 4,128 bees. 



At Winchester in 1915 (Table 2) and Fennville in 1916 (Table 

 4), the weights of the colonies were ascertained only during ancl after 

 the honey flow from apple trees; it is therefore to be expected that 

 the loss in number of bees as indicated by the weights at the close 

 of the honey flow is, because of the decreasing quantities carried in 

 their honey sacs, greater than the actual loss. This expected decrease 

 is verified in the average weight of honey per bee in the samples taken 

 at Fennville (Table 4) ; but, judging from the average weight per 

 bee in the samples taken at Winchester in 1915, this decrease had 

 already taken place before any samples were weighed, since none 

 was weighed on the chemical balances in 1915 until May 2. These 

 weighings are not published, as the season's work was brief and in- 

 conclusive. 



During a 5-day period before the spraying, colony No. IT in the 

 Luj)ton apiary gained 12 ounces, or an average of 2.4 ounces per day ; 

 colony No. 18 gained 20 ounces, or 4 ounces per day. During a 7-day 

 period after the spraying, colony No, 17 gained 18 ounces, or an 

 average of 2f ounces per clay ; colony No. 18 gained 14 ounces, or 2 

 ounces per day. The total gain of 32 ounces for the two colonies both 

 before and after the spraying was begun was certainly due to the ad- 

 dition of young bees to the colony, as the maturing brood had not 

 been removed. It seems evident that the spraying had no effect on 

 the combined weight of all the old and emerging bees; if the old 

 bees were affected their decrease was balanced by an increase of the 

 young ones. 



The figures representing the nectar stored in the combs of the six 

 hives weighed in the hive kept on the scales, and as a daily load per 

 returning field bee, are all in harmony and their curves take the 

 same general direction. 



The weighing experiments showed that the death rate in a normal 

 colony averaged about 600 bees per day, whereas the dead bees 

 caught in the bee traps averaged only about 18 per day, thus indi- 

 cating that about 97 per cent of the bees that died succumbed in 

 the fields. 



In summing up the results of the experiments conducted at Win- 

 chester and Fennville in 1916, and at Drummond in 1917, when the 

 fruit trees were sprayed at the regular time, it appears for several 

 reasons that the spraying did not injure the bees: (1) The daily 

 weight records and the counts of dead bees in the traps show that 

 the bees died more rapidly before than after the trees were sprayed. 

 (2) The gain in weight of all the old and emerging bees before 

 the sj^raying was begun was equal to the gain after, in the case of 

 the two colonies tested. (3) After the spraying was begun the 

 results obtained from the chemical analyses of the samples of dead 

 bees did not indicate that the bees had -died of arsenical poisoning. 

 (4) No symptoms of arsenical poisoning were noticed at any time 

 among the bees. 



