374 The University Science Bulletin. 



Two or three firms securing straw from a grower near Lawrence, 

 Kan., reported serious trouble. An examination of one factory re- 

 vealed fifty per cent of the collars infested. Upon examining the 

 floor, walls and window and door casings, the cracks were found to 

 contain many adult beetles, which in all cases were dead. The 

 light and heat of the sun had a marked influence upon the distribu- 

 tion and development of the insects, as the collars near the south 

 windows were more seriously damaged, the injury decreasing 

 gradually as one neared the north side of the building. 



SOURCE OF INFESTATION. 



Since injury was reported from manufacturers using straw grown 

 near Lawrence, Kan., it appeared possible that the straw might have 

 been infested before it was shipped to the factories. An investiga- 

 tion was made first at the ranch where the rye straw was grown. 

 It was found that the sheaves were stacked up in the barns to con- 

 serve the value of the straw for collar-stuffing purposes, and during 

 the winter months a specially made thresher was used in removing 

 the grain from the head of the sheaf without cutting the band. After 

 the rye bundles were threshed they were baled, being compressed 

 and tied with wire ready for shipping to the collar factory. I found 

 no trace of the insect about any part of the sheaves. They were 

 apparently free in every respect from the insect. I also examined 

 the threshed bundles before they were baled, and noticed that there 

 was considerable grain left in the straw, which later afforded food 

 for the development of the insects in the collar. I next examined 

 the threshed rye in the bin, thinking perhaps the insects might be 

 hibernating at this season of the year. I collected several ciuarts of 

 the rye in a screw-sealed glass jar, to keep out other infestations, 

 and took this, with one of the rye sheaves, to the laboratory. 



I placed some of the rye straw taken from the sheaf in a large 

 glass-enclosed cylinder. This was placed in the incubator at ordi- 

 nary room temperature of 70° F. I recorded the temperature each 

 day and watched for the development of infestations, but noted no 

 development of life for several weeks. At the end of three weeks 

 I found two species of grain weevil and several parasites, which I 

 removed from the jar and placed in separate vials. At the end of the 

 fourth week I removed from the jar five specimens of larva.^, ap- 

 parently of the same species of Dermestidse that was the cause 

 of the collar infestation. April 15, the adults emerged from the 

 pupa^ cases. I found them to be the same species as those causing 

 the damage to the collars. 



