18 



BULLETIN 1222, U. S. DEPARTMENT OF AGRICULTURE. 



their food surrounding them, but a small amount of honey 



(nectar) mixed with pollen may be found on the base of the 



cell and adhering to the larva. 



Full-grown larvae (fig. 11) — that is, 

 lan^se in cells more than half covered 

 by the cap — fill the lower half of the 

 cell so completely that the form of the 

 larva suffers considerable distortion. 

 The body is flattened and the head 

 and tenth trunk segments are crowded 

 back, telescoped into the neighboring 

 segments, and, as the figure shows, 

 are invisible from the mouth of the 

 cell. Larva? of this age, fixed and 

 hardened in the cell, as was the one 

 from which the figure was drawn, 

 form veritable casts of the interior 

 of the lower half of the cell. It 

 should be noted that the head is 

 always nearer the mouth of the cell 



than is the posterior end, the long axis of the larva thus following a 



spiral course. 



SUMMARY AND CONCLUSIONS. 



Fig. 10.- 



-Larva of honeybee, 4 days 

 old. 



Eggs of the honeybee at the commencement of development weigh 

 about 0.132 milligram each. 

 At the close of embryonic de- 

 velopment they weigh from 

 0.08 to 0.1 milligram each. 



Larval development, up 

 to the time of sealing, lasts 

 4| to 5| days. The aver- 

 age weights of the larva 

 obtained from Lots 1 to 5 

 were as follows : First day, 

 0.65 milligram; second day, 

 4.687 milligrams; third day, 

 24.64 milligrams; fourth 

 day, 94.692 milligrams ; fifth 

 day, 157.642 milligrams. 

 Averaging the weights ob- 

 tained under various condi- 

 tions under Lot 8 the follow- 

 ing weights were obtained: 

 Second day, 4.745 milli- 

 grams; third day, 24.626 

 milligrams; fourth day, 

 93.99 milligrams; fifth day, 

 146.748 milligrams; sixth 

 day, 155.005 milligrams; 

 seventh day, 141.647 milli- 

 grams; eighth day, 137.165 

 milligrams; ninth day, 133.152 milligrams 

 day are of sealed brood. 



Fig. 11. — Mature honeybee larva, the half of the 

 cell facing- the observer being removed so that 

 the larva is shown as seen from one side of 

 the cell, and not from the outer end, the base 

 of the cell being- toward the bottom of the 

 page. 



Weights after the fifth 



