94 THE CANADIAN ENTOMOLOGIST 



One of the peculiar features of this species is the prodigality 

 with Avhich it sacrifices its individuals when very young. The 

 oung larvae that feed in the glumes are to be numbered by the 

 dozens in some of the infested heads, yet as far as the study of the 

 species can determine, but one of these can survive in the course of 

 the season. Several often find their way into the stem centre by 

 separate openings, but in\'ariably only one of these appears to sur- 

 vive. Several times one larva in a stem has been found feeding 

 on a half-eaten rival. And it is certain that when winter comes 

 there is but a single individual within each infested stem. Some 

 explanation for this apparently useless expenditure of life may be 

 discovered during future studies of this species, but at present it is 

 an enigma. The reason why a single larva occupies an entire stem 

 is clear, since a single stem affords nourishments for but one borer 

 and self preservation compels the destruction of all competitors 

 by the individual possessing the most vigour or the commanding- 

 position. 



The parenchyma in the upper stem is unbroken and the gallery 

 there is continuous. Farther down, the larva occasionally takes 

 advantage of lesions in the parenchyma and passes sometimes for 

 several inches with no sign of a mine. The nodes are, of course, 

 solid and these are of necessity bored. Near the base of the stem 

 there are few lesions, the larva is much larger, and the gallery is 

 continuous. 



The larva enters the stem during August, and by the middle of 

 October, its progress depending upon the character of the season, 

 it usually reaches the stem base. From lack of vitality or for some 

 other reason a few of the larvae always fail to reach the base before 

 winter, and many of these belated individuals perish during the 

 winter. Those in the hibernation chamber underground appear 

 to survive almost without exception. This chamber is merely the 

 portion of the gallery at the very base of the stem. It is cleared of 

 frass, often but not always lined with delicate, transparent silk, 

 and here the larva hibernates until the middle of the following May. 

 For two years the writer supposed this was also the pupation 

 chamber, but before the end of May the stems are for the most part 

 vacated, the guests disappearing through an opening eaten through 

 the stem about ground level. A fortunate discov^ery solved the 



