24 U.S. NATIONAL MUSEUM BULLETIN 244 



pressure toward a more cryptic color pattern that would better 

 enable the moths to remain hidden from predators during the day. 

 Evidently little adv^^antage lies in this feature for most members of 

 the family, probably because of the very brief life span (approxi- 

 mately 3 days) of the males. Thus, in the Psychidae, one finds an 

 exiguous development of wing pattern observed in several other 

 families of moths (e.g., Noctuidae) that possess longer adult stages 

 and are, therefore, in greater need of such protection. It might be 

 concluded that the function of wing scales (to provide a color pat- 

 tern) has been largely lost in the Psychidae, with the result that in 

 many species the scales have become reduced in area, loosely at- 

 tached, and easily discarded. 



Although its relative unportance is not known, the determination 

 of mating pairs in the majority of psychids can not involve super- 

 ficial features such as recognition characters because the female 

 imago is unable to make a selection in mating and may accept any 

 male that attempts copulation. The larval cases, on the other hand, 

 sometimes display a much greater difference among species, and 

 possibly do initiate a recognition stimulus, along with an oKactory 

 response, in the male. The olfactory stimulation, however, is be- 

 lieved to be of far greater importance in mate attraction, as evidenced 

 by the fact that the males of all known species of Macro-Psychina 

 usually possess broadly bipectinate antennae. Such an antenna 

 provides a greater surface area and, thus, a greater number of ol- 

 factory receptors, assmning, of course, that these receptors are 

 evenly distributed over the antenna. 



The similarity of male genitalia probably is due to the very spe- 

 cialized mating behavior. This procedure makes exacting demands 

 upon these structures, and natural selection largely has prevented 

 extravagant variation from the selected type. In most families of 

 Lepidoptera apparently there is not so great a necessity for such 

 rigidity and compactness of the genitalia, and the result is that more 

 diverse forms have developed within a given group. 



The members of this family are capable of achieving a wide dis- 

 tribution by means of various adaptations. These methods of 

 dispersal enable a species eventually to occupy most of the habitats 

 favorable to its existence, but the methods probably do not provide 

 an efficient means of gene exchange among widely separated popula- 

 tions. It is conceivable that certain widespread species (e.g., Oiketicus 

 kirbyi) are composed of a nmnber of reproductively isolated sibling 

 species. However, this should not be assumed until so proven, or 

 else an even greater number of superfluous names could result, originat- 

 ing from a failure to recognize what actually may be the normal 

 variation in a given species. 



