12 U.S. NATIONAL MUSEUM BULLETIN 244 



The intersegmental membranes of this region are very developed and 

 flexible, providing the necessary surface area for expansion. Relying 

 chiefly upon pneumatic pressure from within its inflated body, the 

 male extends its abdomen the necessary distance for eventual copula- 

 tion. During actual union the moth becomes quiescent and remains 

 suspended, head downward, for a brief period of usually less than 

 ten minutes (Jones, 1927). After completion of the act, the abdomen 

 is slowly withdrawn and the male flies away, often capable of mating 

 again. 



In a few old world genera (e.g., Apterona, Lnffia, and Solenobia), 

 parthenogenetic races are Ivnown to exist. A considerable amount 

 of investigation of these insects has been made, primarily by Seller 

 (1917-49) and more recently by Narbel-Hofstetter (1946-55). It 

 has been suggested, although by no means proven, that partheno- 

 genesis also may occur occasionally in some species which are normally 

 bisexual. 



Egg laying commences immediately after mating. As stated 

 previously, the eggs normally are deposited within the larval case 

 and frequently within the pupal shell. In those species that 

 normally mate outside the case (e.g., Solenobia), the females, after 

 copulation, introduce the abdomen into the lower opening of the larval 

 bag and deposit the eggs in an irregular mass, intermixed with wooly 

 hair shed from the posterior segments of the female. Several authors 

 have suggested that the eggs actually are not laid but mature within 

 the parent's body, the young larvae eventually bursting through the 

 body wall. Generalizations of this nature should be regarded with 

 considerable skepticism until more careful observations can be 

 performed. Following oviposition, the very shrunken female usually 

 succeeds in forcing her way out of the case (if she has not already 

 done so) and dropping to the ground eventually to perish. 



Natural enemies. — Populations of bagworms in some areas of 

 their distribution apparently can be seriously affected by the predation 

 and parasitism of diverse organisms. Previous work in this phase of 

 psychid biology has been quite insufficient, and no conclusions can 

 yet be drawn concerning such phenomena as the frequency of host 

 specificity among some of the parasites. One of the few papers 

 devoted to this area of study has been that of Koehler (1939b), Re- 

 cently published findings by Stephens have shown the existence of 

 several new species of parasites attacking Oiketicus kirbyi. 



Birds, lizards, and certain arachnids are known to prey upon 

 members of the Psychidae. Birds have been noted eating both the 

 larvae and adult females; however, the construction of the larval 

 case sometimes offers adequate protection from such dangers. Oc- 

 casionally bagworm cases are found pierced with holes that apparently 



