THE LESSEE CORN STALK-BORER. 23 



WINTERING. 



In the latitude of Columbia, S. C, this species apparently passes 

 the first part of the winter as a larva and the latter part as a pupa 

 and possibly adult, although it has not been possible to verify this 

 absolutely by rearing experiments. 



Larvae have been found in the field, in their burrows in the stalks, 

 as late as the middle of November, after which time none could be 

 found. Repeated efforts were made at various times during winter 

 to find pupae, and one cocoon containing a papa was found in January 

 which, unfortunately, died. This pupa probably would have changed 

 early in the spring to an adult. 



According to the experiments of the writers in 1915, larvae pupating 

 in the fall did not winter as such but gave rise to moths in early 

 winter. These moths died within a short time, which circumstance 

 would seem to indicate that this species does not winter in the adult 

 stage. Larvae have been kept alive in rearing cages under outdoor 

 conditions up to January, at which time they died, apparently from 

 being kept in closed receptacles, which was very favorable for the 

 development of a fungus which killed them. 



In Arizona the species probably passes the winter in the larval 

 stage, judging from the fact that larvae in all sizes were found as 

 late as November 3 at Tempe, Ariz. 



REARING METHODS. 



In rearing the larvae of this species a number of different types of 

 cages were used, such as the ordinary "pot cage" surmounted by a 

 lantern chimney covered with cheesecloth, or with a celluloid cylin- 

 der covered with cheesecloth. None of these types of cages gave 

 complete satisfaction, for the reason that they could not be made 

 tight enough and the larvae, being very restless, are ever on the 

 alert to find an opening through ^which they may escape. 



Tin salve boxes and the ordinary low-type jelly glass with tin 

 cover proved the most satisfactory of all cages. In rearing these 

 larvae, a small quantity of sand was placed in the bottom of each 

 and kept moistened. These containers were kept supplied with 

 fresh cowpea leaves and a number of larvae were reared in each 

 receptacle. 



To obtain eggs, a cage, consisting of a 6-inch flowerpot saucer, 

 lantern chimney covered with cheesecloth, and a bottle containing a 

 small sorghum plant, in water, was employed with success. 



In making a study of the different instars, small test tubes, used 

 in bacteriological experiments, were found to be the most practical, 

 on account of the convenient size and also because observations could 

 be made without removing specimens. 



