THE CANADIAN ENTOMOLOGIST. 219 



If, in consideration of the condition of the moths wlien captured, the 

 probable different time of oviposition and more or less favorable exposure 

 of eggs, we assume that the individuals of a species continue to emerge 

 from the pupa during one-third of the above period, there will remain, as 

 the approximate life duration of these Noctuidse, a period of three iveeks. 



Mr. Wm. L. Devereaux, of Clyde, N. Y., in giving the results of his 

 collections of Noctuidi?e at sugar for two years,* states that "most of the 

 species remain for about a month." From other data which I have con- 

 sulted, I think that we shall not be far from the truth if we adopt as the 

 life-period of the larger portion of the Noctuidse a term of three weeks. 



As might be expected in so heterogeneous a family as the Noctuidas — 

 differing so greatly in general character, coming forth at such different 

 seasons of the year, and varying in the number of the broods, — the life- 

 histories of the several groups vary to the extent of preventing generaliza- 

 tion and necessitating specific observations. For example, we find that 

 the genera Xylina, Homoptera and Catocala have their periods of 

 apparition much extended beyond the species above noticed. In the 

 paper by myself, above referred to (p. 51), we find that Xylina pettdca, 

 X. dispoiita and X. Beihuuci were observed for a period extending over 

 forty-one, forty-seven and fifty-one days respectively, with a possible pro- 

 longation of the lives of some of the later individuals through hibernation 

 and reappearance in the following spring, of six additional months. Seven 

 species of Catocala give an average duration of forty-five days, and from 

 Mr. Devereaux's observations, nine species of Catocala give an average 

 period of fifty-seven days. These last may have shown a prolonged period 

 from their extending over two years — one of which, from a more favorable 

 season, may have included earlier dates of first appearance. It is proper 

 to state that the above species were selected from the lists, as having been 

 observed for the greatest length of time ; the larger number gave consid- 

 erably shorter terms of apparition. 



In concluding these brief notes, which are quite unsatisfactory to 

 the writer, and offered only in compliance with request, I would beg leave 

 to suggest that good service may be rendered to Entomology by the 

 collation from published records, and incorporation in our published lists 

 of insects, hereafter, of the several dates of their collection or observation 

 throughout the entire time of their appearance. The want of such data 



Canadian Entomologist, vol. xi., pp. 105- 1 09, 1 879. 



