PROC. ENT. SOC. WASH., VOL. 20, NO. '2, FEE, 1918 27 



ON THE LEPIDOPTEROUS GENUS OPOSTEGA AND ITS LARVAL 



AFFINITIES. 



BY CARL HEINRICH, 



Specialist in Forest Lepidoptera, U. S. Bureau of Entomology. 



It has been the writer's good fortune during the past year to 

 be able to study the larvae of two species 1 of this interesting 

 genus and to ascertain certain facts in regard to the modification 

 of the head capsule and trophi which throw considerable light 

 on its relationship to other bark and leaf-mining Microlepidoptera. 



The proper position of the genus Opostega in lepidoptera classi- 

 fication has been uncertain. Meyrick (6-7) associates it with 

 Bucculatrix, Lyonetia, Phyllocnistis, Leucoptera, etc. in his con- 

 cept of the family Lyonetidae Spuler (8) places it in the sub- 

 family Oposteginae under the Nepticulidae. Busck (2) likewise 

 connects it with the Nepticulidae and our latest list (1) follows 

 him in this; but in all late classifications, Leucoptera (Cemiostoma) 

 and Lyonetia with which Opostega has much in common are 

 placed far from Nepticula. Both groups have a number of char- 

 acters in common, the large developed eye caps, maxillary palpi, 

 and the short drooping labial palpi. Both show a corresponding 

 advance in venational development. On the other hand the 

 Nepticulidae as well as the Tischeriidae, Opostegidae, Adelidae, 

 Prodoxidae, Incurvariidae and Micropterygidae all possess certain 

 aculei on the wings which are lacking in the Leucopterygidae 

 (Cemiostomidae), and it is the retention of this primitive and 

 significant character which has largely determined the placing 

 of Opostega with Nepticula and away from Leucoptera. The 

 venation of Opostega is the most advanced in the Lepidoptera. 

 The forewings have no cross veins and only three horizontal 

 veins, and in the hind wings the venation is reduced to six veins, 

 (3 and 4 absent, and the cell open between 2 and 5). If \vc 

 compare this venation with that of any species of Nepticula or 

 with that of Leucoptera (L. spartifolieUa Hbn. for example) we 

 can easily understand how it could be derived from either one. 

 Both in the Leucopterygidae and Nepticulidae reduction in vena- 

 tion is going on at a rapid rate, but by methods somewhat dif- 

 ferent. In Opostega the result has been achieved and nothing 

 remains to show if it has followed the tendencies exhibited by 

 the one or the other of the two groups or, for that ma 1 1 rr, followed 

 a course different from either. And this is significant; for it 



1 An unnamed ()/HI.I< </// species from Honolulu, T. H., mining the leaves 

 of "Pela," collected by .Mr. Otto II. Swc/ey i.l!iir>i, and <>. nonstrigella 

 < Miami)., larva found mining stems of Kibis and mot lis reared by .Mr. J. (', . 

 < irossenbacker (Geneva, X. V., 1910). 



