56 



Annals Entomological Society of America [Vol. XI, 



Table III. 



During the first three' instars the larvae fed mostly by 

 skeletonizing the leaf, leaving only the membrane on one side. 

 Part of those in III and all from that time on consumed the 

 entire leaf. The amount of food consumed progressed in a 

 fairly definite ratio, the amount eaten in any instar being about 

 100% greater than that eaten in the preceding instar. In this 

 respect a larva about to pupate behaved differently than one 

 still growing for during the last instar its desire and capacity 

 for food seemed almost insatiable until within two or three 

 days of pupation when it ceased entirely to feed, contracted, 

 became sluggish and prepared for the change. It is note- 

 worthy that larvae of this species did not eat the molted larval 

 skins and head casts as do those of many species of Crambus. 

 The larvae in the series of which the food record was kept were 

 given measured pieces of bluegrass leaves and at the end of 

 each instar the uneaten portion was removed and measured. 

 A skeletonized leaf was considered to be two-thirds consumed. 

 Table IV shows the amounts of food consumed by the larv« 

 in each instar in linear millimeters of bluegrass leaves which 

 average about 3 mm. in width. 



Table IV. 



BLUEGRASS LEAVES IN LINEAR MILLIMETERS CONSUMED. 



