REPORT OF THE STATE ENTOMOLOGIST I913 I9 



carbon bisulphid or hydrocyanic acid gas. A badly infested building 

 might require several treatments, and owing to the habits of the 

 pest, it is obvious that not much reliance can be placed upon 

 fumigating the infested grain itself, since the insects leave it 

 in large quantities prior to changing to the moth. It may, in some 

 instances, be necessary to provide nearly gas-tight rooms for the 

 storage of grain, so that in cases of serious infestation the apart- 

 ment and its contents can be easily and safely fumigated. Another 

 method of obtaining the same end is by making provision for heat- 

 ing storage quarters to a temperature of 120 degrees and holding 

 it there for at least 30 minutes. This has been tried on an ex- 

 tensive scale in flour mills with very satisfactory results. It is 

 perhaps needless to add that the resistance of seeds to this treat- 

 ment should be carefully ascertained before the method is exten- 

 sively used in seed warehouses. 



Bibliography 



Below are given a few of the more important references to American 

 literature relating to this species : 



1895 Chittenden, F. H. Year Book, U. S. Dep't Agric , p. 286-87. 



1897 U. S. Dep't Agric, Div.' Ent. Bui. 8, n. s., 31 :3s. 



1906 Britton, W. E. 6th Rep't of Conn. State Ent., p. 234, 294-95, 305. 



RHODODENDRON CLEAR-WING 

 Sesia rhododendri Beutm. 



Wilting or yellow rhododendron leaves are signs which may 

 indicate the work of the whitish caterpillar of this species, particu- 

 larly if the evidences of injury are confined to a branch or por- 

 tion of a stem. This borer limits its operations largely to stems or 

 branches a foot or more above the ground. It appears to be gen- 

 erally distributed in the New York Zoological Park as shown by 

 specimens forwarded by Mr Herman W. Merkel, and Mr G. P. 

 Engelhardt of the Children's Museum informs us that it is common 

 in and about Prospect Park, Brooklyn. The species has also been 

 recorded from Cheltenham, Pa., and, according to its describer, is 

 closely allied to S. p y r i Harr. and S. s c i t u 1 a Harr. 



Habits and life history. The young larva frequently works just 

 under the bark and in the sapwood, excavating an irregular, longi- 

 tudinal, more or less frass-filled gallery some 3 inches in length and 

 terminating in an irregular, oval, sparsely silk lined cell about three- 

 eighths of an inch long where the insect evidently hibernates. This 

 borer 5hows a marked tendency to excavate one or two broad, short. 



