186 JOURNAL OP ECONOMIC ENTOMOLOGY [Vol. 2 



The larv£e are fed often by the attending workers upon regurgita- 

 ted, and presumably predigested, food. There is nothing in the ap- 

 pearance or actions of the workers which do the feeding to indicate 

 that they are different from those which perform other duties, or 

 that they are assigned to the particular and exclusive duty of being- 

 nurses. The feeding of the larvte has several times been observed 

 under a magnifying glass and is as follows: The larva ordinarily 

 lies upon its side or back. The attending worker approaches from any 

 convenient direction, usually from one side or from the direction in 

 which the head of the larva lies and, spreading her mandibles, places 

 them over the mouth-parts of the larva wliich are slightly extruded. 

 The tongue of the worker is also in contact with the larval mouth. 

 While the worker holds body and mandibles stationary a drop of 

 light-colored, almost transparent fluid appears upon her tongue. This 

 fluid disappears within the mouth of the larva, but it cannot be as- 

 certained to what extent the larval mouth-parts are moved during 

 the operation, owing to their being obscured from view by the mandi- 

 bles and head of the attending worker. Slight constrictions of the 

 larval abdomen during feeding are sometimes noticeable, at other 

 times not. The time required for feeding a single larva varies from 

 3 to 30 seconds, depending doubtless on the hunger of the "baby." 



The workers proffer food to, or at least inspect, each larva, for the 

 worker doing the feeding will place her mandibles to the mouth of 

 one larva after another, feeding those which seem to require it. 



Both larva^ and pupte are groomed or licked with the tongues of 

 the workers; thus are they ever kept in a state of absolute cleanliness. 



The most pronounced increase in size of the larvae occurs during 

 the first five days after hatching; after that it is relatively slower. 

 As the larva increases in size the contents of the alimentary canal, 

 dark in color, can be seen through the walls of the abdomen. 



Just prior to transformation into pupa, the larva takes on a rather 

 characteristic appearance, which if it were more distinct, would jus- 

 tify characterization as the "pre-pupal" stage. In this stage the 

 cephalic and thoracic portions of the larva become markedly smooth 

 and shining, with segmentation indistinct or absent. At the same 

 time the line of demarcation between thorax and abdomen becomes 

 more distinct and the contents of the alimentary canal appear to be 

 shifted nearer to the caudal end than in the larva proper. The 

 mouth-parts, indistinct in the larval stage, now appear more prom- 

 inent. The difference between larval and pre-pupal stages is by no 

 means pronounced, but with practice one can predict the approaching 

 transformation to pupal stage by it with reasonable accuracy. 



