DESTRUCTION OF FRUIT BY ALETIA. 87 



shown by Fig. 4; and the portion immediately preceding the tip is 

 equally well adapted for rasping, being furnished with numerous spines 

 on the dorsal surface. The ventral surface of this part of the organ is 

 is also provided with spines. 

 Probably these are of little use 

 in piercing the rind of fruit, but 

 doubtless they aid much in en- 

 larging a hole when it is once 

 made, and also in lacerating 

 the pulp of fruit, thus setting 

 free the juice. Fig. 5 repre- 

 sents a crOSS section of the max- FiG. 5. Cross-section of maxilla?, 

 ilhe. The relation of all the parts is well shown, excepting the arrange- 

 ment of the muscles which are within the walls of each maxilla. These 

 muscles were torn in cutting the section.* 



Although many Lepidoptera may be found to possess the power of 

 piercing the rinds of fruits when the subject is more carefully studied, 

 as yet but few instances have been observed. The following is the most 

 striking: An Australian -moth ( Opliidercs fullonica) is very destructive 

 to oranges. This insect is furnished with maxillae similar to those of 

 Aletia aryillacea, with which it is able to pierce the thick skin of the 

 orange. Figures and careful descriptions of the structure of the maxillae 

 of this orange-sucking moth have been published by M. Kiinckel, Cornptes 

 Reudus, August 30, 1875, and Francis Darwin, Quarterly Journal Micro- 

 scopical Science, 1875, p. 384. Mr. Darwin also states, on the authority 

 of Mr. K. Trimen, Curator of the South African Museum, that at the 

 Cape of Good Hope a great deal of fruit is thus injured by Lepidoptera. 

 Other instances of Lepidoptera piercing vegetable tissues for the pur- 

 pose of obtaining the juices are given by the elder Darwin in his work 

 on the fertilization of Orchids. 



Although there is no doubt respecting the ability of the moths to per- 

 forate the rinds of fruit, it is evident that they will seldom do so if it 

 can be avoided. Thus, when one moth has made a hole through the 

 skin of a peach, others crowd around and make use of the same opening. 

 I have observed seven moths making use of a single perforation at one 

 time. In this way the juice of the peach is extracted, only a spongy 

 mass being left. In feeding upon figs, however, the moths frequently, 

 instead of making use of the natural opening of that fruit, pierce the 

 outer rind. Mr. Trelease made careful notes respecting the manner in 

 which the moths feed. These are published in his report. (See Appen- 

 dix I.) 



* As this report is written chiefly for those who have not made a special str.dy of en- 

 tomology, a few words in explanation of the structure of the maxillae of moths will 

 not be out of place. In their simplest form, the mouth parts of insects consist of an 

 upper lip, an under lip, and two pairs of jaws acting horizontally between them. In 

 the case of butterflies and moths (Lepidoptera') the lower pair of jaws is devt ;oped into 

 two long, flexible organs ; each of these has on one side a groove, and the two are 

 fastened together so that the grooves form a tube, as shown in the center of Fig. 5. 



