One of these Exyras, rolandiana, is consistently associated with Sarracenia purpurea through- 

 out much of that plant's wide geographical range. Wine-red, yellow, and smoky purple in 

 color, this moth matches well the highly colored walls of the open-topped pitcher in which 

 it sits by day. The other two Exyras, semicrocea and ridingsii, are not found north of Virginia; 

 they retain their (probably) ancestral colors of dull yellow contrasted with smoky black, and 

 they are habitually associated with those other Sarracenias whose hooded or lid-covered 

 pitchers offer better concealment from outside view, so that color for these moths may not 

 have the same significance. 



The moths lay their minute eggs on the inner walls of the pitchers. Hatching from 

 these, the little caterpillars, throughout life and by various devices, maintain for themselves 

 closed feeding chambers, in which they may live with some degree of concealment and pro- 

 tection from external foes. This they accomplish by closing the mouth of the pitcher above, 

 and by feeding below only on the inner layers of the pitcher's wall, until this is reduced to 

 a bladderlike thinness, the caterpiller as it feeds sealing all accidental holes and fissures with 

 silk. To close the pitcher's mouth, one of several alternative methods is employed. The more 

 prevalent of these is to spin a fine, close, and almost opaque web across the throat of the 

 pitcher; or in a young and tender pitcher, a tightly closed chamber is often attained by eat- 

 ing a threadlike groove encircling the upper portion, above which groove the pitcher dies, 

 dries, and hardens, thus effectually and permanently closing the pitcher at the top. One or 

 the other of these methods is usually followed, either to obtain a closed feeding chamber 

 with its added safety, to provide a retreat for pupation, or in the autumn to prepare a hiber- 

 naculum for the young larva, which must survive the winter in that concealment; for thus 

 all the Exyras pass the winter, each ensconced in a pitcher of Sarracenia. 



The young larva of semicrocea, when it finds itself in the narrow-throated pitcher of 

 psittacina, varies this method by closing the pitcher's constricted throat with a dense wad 

 of chewed vegetable fragments and silk, ensuring for itself a watertight compartment for 

 the winter; and ridingsii, in its larger pitcher, constructs a vaulted chamber among the refuse 

 of its own feeding. 



When about to pupate in a web-ceiled pitcher, the caterpiller of Exyra makes no provi- 

 sion for the exit of the moth, which by slight pressure from within is able to force a way 

 through the thin web; but in the narrow-throated pitchers of psittacina, or in the purpose- 

 fully collapsed pitchers of jiava, the larva, before spinning its cocoon, cuts a small round hole 

 in the pitcher's wall as a provision for the emergence of the moth to be, which would 

 otherwise be unable to find or force its way out to the open air. 



These and other adjustments of Exyra to life within the pitchers of Sarracenia are in the 

 main psychical rather than structural; but in various stages of their existence structural modi- 

 fications, too, seem to relate to life within the pitchers. In illustration, along the bodies of 

 the caterpillars of the two Exyras which live in the narrow-tubed southern Sarracenias are 

 several strongly spined elbowlike projections which hold them out from close contact with 



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