THE CANADIAN ENTOMOLOGIST. 263 



• 



This was, I believe, until a comparatively recent period the view uni- 

 versally held by Entomologists. In the First Annual Report of the U. S. 

 Ent. Com. relating to the Rocky Mountain Locust, published in 1878, 

 Mr. Riley states that he has found the larva of this species, E. pennsyl- 

 vanica, along with those of other species of the same genus, feeding on 

 the egg masses of the Rocky Mountain Locust, Caloptenus spretus, and 

 has bred the perfect insect therefrom. This statement had escaped my 

 notice. Wm. Saunders. 



CORRESPONDENCE. 



dr. hagen's mystery. 

 Dear Sir, — 



My writings on Pronuba yuccasella have induced considerable discus- 

 sion and comment, both from horticulturists and entomologists. Many 

 of the criticisms of my conclusions are unworthy of notice and have not 

 been noticed by me } but the note from Dr. Hagen in your July number 

 cannot be passed in silence. Just as I had, in the J une and July numbers 

 of the American Entomologist, dispelled much of the " mystery " regarding 

 this little moth and shown that the conflicting experiences were due to 

 the confounding, by my critics, of another species ( Prodoxus decipiens) 

 with it, Dr. Hagen increases the " mystery " by his statements in the note 

 referred to. His statements are positive and circumspect, but I am as 

 fully satisfied that he has in some way made a mistake as I am that others 

 have been mistaken who wrote with equal assurance on the subject of 

 Pronuba. I have obtained in all from the stems of Yucca some forty 

 specimens of Prodoxus, none of them showing any sign of the maxillary 

 tentacle of Pronuba, and it would be strange indeed if Dr. Hagen's two 

 individuals formed such a remarkable exception. I write this upon first 

 reading his note, but as I expect shortly to have the privilege of examin- 

 ing the specimens, I will wait and see what light I can then throw upon 

 this last " mystery." 



Regarding Dr. Hagen's unwillingness to send me a specimen of the 

 Yucca stem larva, I have simply to say that upon learning from Mr. 

 Thomas Meehan that he had sent to Dr. Hagen what, from my previous 

 experience with it, I thought was probably Prodoxus decipiens, I greatly 



