1889.] 



THE YOUNG NATURALIST. 



The Determination of Species of Lepidoptera by 

 examination of their Anal Appendages. 



By F. N. PIERCE. 



As we grow older we constantly notice changes in familiar objects ; 

 changes in animals, changes in insects, in fact as the great poet has 

 written — " Change and decay in all around I see." Some of these 

 changes are real, some are simply changes of name : but why should 

 names change ? Is it the progress of education ? In insects, the 

 particular group with which we have to deal, we find many changes 

 in the names. I do not intend to say anything about the synonomy 

 and laws of priority, these are better in abler hands than mine; 

 but what I wish to draw attention to, are the changes certain 

 insects have undergone in their names apart from synonymy. We have 

 only to look at the older lists to find that what were considered two 

 species then, have been united as one species now, from the fact of 

 both being bred from ova laid by one parent. Where are now Epinephele 

 janira and jurtina, Camptogvamma fluviata and gemmata, Nemeophila russula 

 and sannio, and many others ? We find them united under one name, 

 and those whom God joined together are no longer separated in the lists. 

 This has been done by careful study in breeding. In the same way single 

 species have become two, for example : Caradrina alsines and blanda, 

 Notodonta dictcea, and dict&oides, A crony eta psi and tridens, have been 

 separated when we found by breeding that although the imagines are 

 so alike the larvae are different. Then again we find what were con- 

 sidered two or more species differing in coloration and markings, and 

 occurring in distant localities, such as Lyccena agestis, salmacis, and avtax- 

 erxes, CcBnonympha davus, rothliebii, and laidion, from examination of the 

 larvae, and being bred in a different locality, proved to be local forms 

 of one species. Being a specialist only in lepidoptera, I have been 

 obliged by want of knowledge of other orders, to select my examples 

 from the lepidoptera, but I know similar cases are equally numerous 

 in other orders. All these facts were not found out in a day, but are the 

 result of mutual assistance and careful study ; therefore we are a little 

 surprised when we see entomologists, high up on the rungs of 

 authority, discussing the distinctness of a species by the mere mark- 

 ings and size, particularly species in such a closely allied genus as the 

 Zygcmidce. Unfortunately, not only is very little known of their earlier 

 stages, but some of them are so rare and difficult to rear, that there 



