GROWTH AND FEEDING OF HONEYBEE LARVAE. 9 



observed, but by comparing the weights given in Table 2 with the 

 results given in Table 1 it may be seen that there is less variation 

 with the method here described. 



OBSERVATIONS, LOT 8. 



EFFECT OF NO HONEY-FLOW. 



As will be noted from Table 2, a majority of the weighings here 

 recorded were made during August. In the region of the Bee Cul- 

 ture Laboratory (Somerset, Md., near Washington, D. C.) there 

 is generally at this time of year an absolute dearth of incoming 

 nectar and a consequent depletion of the reserve stores of the colonies. 

 It was noticed that the average weights of the older larvae, par- 

 ticularly of those over 4 days old, were consistently less than the 

 values given in Table 1, Lots 1 to 5, for these ages, in certain cases 

 as much as 6 to 8 per cent. In fact, many of the older larvae that 

 were presumably of the desired age were discarded because they 

 were abnormally under weight. The weights for the age period 

 below 4 days did not show this marked divergence, presumably be- 

 cause by the method used the variation in feeding in relation to 

 the position of the larvae on the frame was to a large extent elimi- 

 nated. Most of the earlier observations (Lots 1 to 7) were made 

 during June and July, at a time when there is generally some nectar 

 flow from clover and other flowers sufficient to keep the bees from 

 drawing on their reserve stores. It was suspected in these experi- 

 ments that the lack of stimulation might be affecting the weights and 

 rate of growth, thereby somewhat lengthening the larval period and 

 lowering the maximum weights. The fact that the majority of the 

 larvae observed usually were not capped until about 18 to 24 hours 

 later than most of those observed in Lots 1 to 7 seems to bear out 

 this assumption of slower development. 



No observations were made on the time period of emergence as 

 adults, although the decrease in weight continued into the pupal 

 period. It is known, however, that with certain other insects a 

 scarcity of food often materially lengthens the developmental period. 

 As stated above, insufficient food has a marked effect upon the 

 weights of larvae and even of adults. 



Honeybee larvae are peculiarly adapted for rapidly consuming and 

 assimilating large amounts of food. Little energy need be expended 

 except for the slight movements of feeding. Therefore practically all 

 the food assimilated is used for the growth of tissues or is stored for 

 future use as required during pupation. As a result the rate of 

 growth should be more or less proportional to the composition and 

 amount of the food consumed, and probably would be more noticeable 

 with the more simple food of the later stages. Anything affecting 

 the amount of this unpredigested food would consequently affect the 

 rate of growth. 



EFFECT OF STIMULATION. 



In an attempt to demonstrate whether the above assumption is 

 correct, several series of larvae were subjected to conditions more 

 nearly resembling the stimulative effects of a honey-flow. Frames 

 containing eggs of known age were placed for development in a 



69525°— 24 2 



