GROWTH AND FEEDING OF HONEYBEE LARVAE. 7 



the same season out with approximately the same weather condi- 

 tions. In the case of two earlier lots from eggs of known age, not 

 here recorded in detail, the larvae were sealed between 5 and 5^ 

 days, the sealing beginning when the larvae were about 5 days old and 

 continuing for some hours. 



The individual differences in the time of sealing are well illustrated 

 by the larvae of one of these lots. These were all of equal age (with- 

 in 2 hours), located on the same comb and therefore presumably 

 subject to approximately identical environmental conditions. When 

 the larvae were approximately 5 days old, there were 43 larvae on 

 one side of the comb. Six of these were already sealed, while about 

 half of the remainder showed a thin rim of wax around the mouths 

 of the cells, indicating that capping had just commenced. Two and 

 a quarter hours later about one-fourth of those cells open previously 

 were sealed. At this rate it would require from 8 to 10 hours addi- 

 tional for the sealing of all cells to be completed. Such differences 

 are typical of all the lots. 



The data given for Lot 5 suggested that the sealing of the cell 

 is commenced before the larva has attained maturity. To test this 

 conclusion additional weighings were made from the same colony 

 as follows: 



Milligrams. 



4 larvae from cells whose edges were just beginning to 



show signs of capping averaged 137. 60 



5 larvae in which sealing was slightly more advanced aver- 



aged : 142. 20 



10 larvae from cells one-fourth to one-third sealed averaged- 141. 00 



10 larvae from cells one-third to one-half sealed averaged 158. 21 



10 larvae from cells over one-half sealed averaged 157. 20 



15 larva? from freshly sealed cells averaged 158. 31 



These figures show clearly that the sealing of the cell is actually 

 commenced when the larva lacks about 20 milligrams of its final 

 weight, and that the larva is fed until the cap covers about one-third 

 of the mouth of the cell, at which time the larva attains its maxi- 

 mum weight. The completion of the cap probably occupies only a 

 short space of time. The weight of mature larvae is also shown to 

 be quite constant, at least for a given colony at the same season of 

 the year. Only one marked divergence from the average for this 

 colony was noted, this occurring in Lot 5, in which a single sealed 

 larva was found to weigh 171.3 milligrams. 



EFFECTS OF UNDERFEEDING. 



It has been shown by Herms (2) and Whiting (11) for two species 

 of the fly Lucilia (Z. caesar L. and L. sericata Meig.) that undersized 

 flies are produced by underfed larvae. A similar condition is found in 

 the boll weevil (Anthonomus grandis Boh.), in which it is stated that 

 the size of the adult varies in almost direct proportion to the abun- 

 dance of the larval food supply and the length of the period of larval 

 development (3). 



The following experiment was tried to determine whether the 

 same relation exists between larvae and adults of the honeybee. Ten 

 larvae, all decidedly below the average maximum weight, and there- 

 fore not fully fed, were taken from a normal colony, weighed and 

 placed in artificial cells formed by making several deep cylindrical 



