152 Journal New York Entomological Society. [Vol. vi. 



This species is more generalized than its ally, T. pallida. It is the 

 stem form, from which pallida is just beginning to diverge. It is the 

 more northern form of the two and in this again shows its ancestral 

 condition, since, belonging to the Palsearctic Eucleids, it is less distantly 

 removed from the ancient habitat of the group. 



Affinities, Habits, Etc. 



This larva is closely allied to T. pallida. It has all the same struc- 

 ture and coloration, differing only in certain details which might be 

 considered to be of but varietal rank, except that they prove to be con- 

 stant. The certain differentiation of these larvfe is difficult except when 

 the whole life history is seen, and then a number of differences appear. 

 The real difference between the species is found in the date of occur- 

 rence. The moths of testacea emerge unusually early, nearly a month 

 before the allied species. My dates are June ioth to 14th for moths 

 bred at Long Island. Professor G. H. Hudson finds June 9th to 22d 

 for all the moths he has taken at light at Plattsburgh during a series of 

 years. Consequently, full grown larvae are found early, often during 

 July at the time when T. pallida is hatching. This is not a case of two 

 differently colored broods, as I thought at one time. Both species are 

 strictly single brooded, like all the other northern Eucleids. The power 

 of early emergence gives T. testacea a northern range, since it pupates 

 in time to avoid early frosts. In the Adirondacks it was the only Eu- 

 cleid met with. 



The larva is a rather low feeder, occurring in the same situations as 

 its ally, T. pallida. The habits are the same. There are seven larval 

 stages, occasionally six by the omission of stage II and still more rarely 

 eight by the interpolation of an extra stage before the last, as Mr. L. 

 H. Joutel tells me happened to a larva that I sent him to breed. 



Criticism of Previous Descriptions. 



I have no references to this larva as such. Probably the descriptions 

 referred to T. pallida cover testacea in part, but I find it difficult to sort 

 them out without dates of occurrence. The diagnosis given by Miss 

 Morton and myself (Journal N. Y. Ent. Soc, III, 146) of (?) T. 

 testacea refers more probably to Kroncea minuta Reakirt. Miss Morton 

 thought she had bred the larva, getting an imago testacea, but there 

 must have been some error. I followed her opinion at the time of 

 writing the synopsis as I had not then bred testacea myself. A corrected 

 table will be given at the end of these articles. My account of T. pal- 



