THE CANADIAN ENTOMOLOGIST, 181 



like external conditions of existence act differently, that temperature, 

 moistufe, food, &c., do not influence them alike. We can understand 

 how this great latitude in susceptibilty to like conditions may and does in 

 the case of exceptional seasons prove beneficial to the species by pre- 

 serving the exceptional individuals that display the power to resist the 

 unusual changes. 



The next paper was by the same author, on New Insects Injurious to 

 American Agriculture, in which attention was called to several insects 

 hitherto unknown as injurious, which during the present year have proved 

 very destructive to one crop or another. Such hitherto unknown and 

 unreported injury is either caused by — ist, imported species ; 2nd, native 

 species previously known but without destructive habit ; 3rd, unknown or 

 undescribed species. 



Mr. W. H. Edwards then read a paper on certain habits of Helicmia 

 charitonia. 



Some interesting discussions followed the reading of these papers, after 

 which an informal discussion on Entomological subjects took place, in 

 which many of the members joined. The meeting then adjourned. 



On Friday, at 11.30 a. m., the Entomological Sub-section held another 

 session. 



The first paper, " On the Length of Life of Butterflies," was read by 

 W. H.' Edwards, followed by one on the Life Duration of the Heterocera, 

 by J. A. Lintner, both of which will appear in the pages of the Ento- 

 mologist. 



A few remarks were made by C. V. Riley on his own extended obser- 

 vations on the duration of the lives of both butterflies and moths, indi- 

 cating that they were as a rule of very short duration. 



Cyrus Thomas stated that according to his observation the Army 

 Worm, as a caterpillar, a chrysalis and a moth, existed in all seventy-seven 

 days. Some observers had, however, made it seventy-six, others seventy- 

 nine days. He contended that in confinement, in a proper temperature 

 and with ample food, the Army Worm passed through its metamorphosis 

 more quickly than in natural conditions. 



B. P. Mann disagreed with Mr. Thomas on this latter; so also did 

 C. V. Riley, it being contrary to their experience. 



J. A. Lintner, State Entomologist of New York, then read a paper on 

 " A Remarkable Invasion of Northern New York by a Pyralid Insect." 



He said that about the middle of May, of the present year, a serious 



