BAGWORM MOTHS OF THE WESTERN HEMISPHERE 17 



general form to the Tineidae. In the higher psychids, however, all 

 body appendages have become vestigial and the body wall 

 largely membranous. The external genitalia, in addition, vary from 

 poorly developed to almost nonexistent. For these reasons it is 

 doubtful that practical taxonomic characters, applicable on the specific 

 level, ever will be discovered for many of the females. One feature of 

 the female is apparently present in all known species, and thus it 

 provides a good character for the family as a whole: the anal hair tuft; 

 however, it is not entirely unique but is believed to occur in certain 

 tineid moths (e.g., Kcarfottia) . 



Both the internal as well as the external genitalia were examined for 

 as many species as available. Major differences were observed among 

 widely separated genera, and minor ones were sometimes found among 

 closely related groups (e.g., Oiketicus and Thyridopteryx) ; however, 

 characters for differentiating species apparently are largely absent 

 within a given genus. Small differences in the external genitalia of a 

 few species of Oiketicus, after a sufficient series has been studied, may 

 be determined to have reliable value; considerable variation, however, 

 in the structm^e of this organ is known to exist as noted in approxi- 

 mately four dissections each of 0. kirhyi and 0. platensis. No scleroti- 

 zation is known to occur within the internal organs, but a heavily 

 chitinized and basiphilic structure, which has not been named, was 

 characteristically present in the spermathecal duct of all the psychids 

 examined. This elongate structure in part may serve in keeping the 

 lumen of this tube open. The most divergent feature of the internal 

 genitalia were the bifid accessory glands that, owing to their pronounced 

 variability, are probably not of specific value within a particular genus. 



Pupa. — Certain external structures (e.g., ridges, furrows, minute 

 spines, and anal hooks) that evidently are of taxonomic importance 

 are present on the male and female pupae. These have been 

 discussed by Jones (1945) and heavily relied upon by Koehler 

 (1939a). Unfortunately, the structm'es have not been investigated 

 sufficiently for inclusion in the present study. 



More attention has been given to the female pupa; considering 

 the extreme reduction of the adult, adequate characters in this form 

 would be very desirable. In this sex, various rugosities on the 

 posterior abdominal segments (the pygidium, in particular) have 

 been employed primarily for specific identification. A review of 

 the works of Jones and Koehler shows that these minor characters, 

 like those of the larval case, have limited application in the 

 classification of the family as a whole. In some instances generic 

 groupings possibly may be indicated by pupal characters, but this 

 has not been confu-med. Presently it is believed that such characters 

 are essentially of only specific importance, and thus they should be 



