14 BULLETIN 123, UNITED STATES NATIONAL MUSEUM. 



The genus as here deJBned represents one group of those species 

 which formerly constituted the genus Retinia or what we in recent 

 years have been wrongly calling Evetria. The type of the latter 

 {tedella Clerck) is nowise related to any of the species that have been 

 cited as Evetria, and is congeneric with similana Hiibner the type of 

 Epinotia. Evetria must fall therefore as a synonym of the latter. A 

 study of the different coniferous bud, shoot and cone moths showed 

 that among those Olethreutids without the costal fold there were 

 three distinct groups, each with its own peculiar type of genitalia and 

 a correlating specialization of larval habit, and representing what I 

 believe to be three closely related but distinct genera. They have been 

 till now considered as one genus {Evetria of authors not Hiibner) 

 which was retained on the connate character of veins 4 and 5 of the 

 fore wing, a lumping that can not be maintained unless we are willing 

 to ignore genitalic characters altogether. In that case, everything in 

 the subfamily might as well go into Eucosma for, unsupported, the 

 venational character is no better than any other. On the whole it 

 holds, but in several Eucosina 4 and 5 are so closely approximate that 

 it requires an effort of the imagination to distinguish them as not con- 

 nate. I have been compelled to use the character in my generic key ; 

 but I should hate to rest a genus on it alone. Furthermore, the larval 

 habits and structure indicate the same lines of generic cleavage as the 

 genitalia. 



In Rhyacionia the larvae feed only on pines, boring into the buds 

 and from them into the new growth of the stems. Their presence is 

 usually indicated by a resinous exudation about the buds; but none 

 of them cause pitch nodules to form on the stems. 



In Petrova the larvae bore into the stems, branches, and bark of 

 both pines and spruces, some species favoring the new and others the 

 older growth. None of them attack the buds and all cause a nodule 

 like exudation of pitch to gather on the part of the tree attacked. 

 This nodule is quite characteristic, being a round dirty lump of pitch 

 and frass. Within it they rest when not feeding and within it they 

 pupate. The larvae themselves have an extra seta on the abdominal 

 prolegs. In every other genus in the Olethreutidae as far as I know 

 there are only three setae in Group VII on the prolegs. In Petrova 

 there are four. 



In Barlara the larvae all feed in the cones of spruce. None of them 

 attack the buds, stems, bark, or other parts of the tree. 



KEY TO THE SPECIES OF RHYACIOXIA. 



1. Fore wing silvery white, transversely lined and blotched v^ith pale faun 



color (10) subcervinana. 



Fore wing otherwise 2 



