ART. IV.-TINEINA AND THEIR FOOD-PLANTS. 



By V. T. Chambers. 



The following is intended as a catalogue of plants which are fed upon 

 by the Tineina within the limits of the United States and Canada so far 

 as they are at present known. 



The best descriptions of these insects may fail to enable one to identify 

 captured species, when, as frequently happens, two or three minute spe- 

 cies differ only in a shade of color, or in the presence or absence of a 

 mark of microscopic dimensions ; but when the larvse, food-plants, and 

 modes of larval and pupal life, with the character of the mines in 

 mining species, are known, there need be little difficulty in recognizing 

 bred specimens. With knowledge of an insect in these particulars, even 

 a very imperfect description of the imago will usually enable us to recog- 

 nize a species which has been bred from the larva, for although two 

 species may resemble each other so closely that even the best written 

 description may not enable us to determine which of the two it is, yet 

 it will be a very rare occurrence that this close resemblance will hold 

 good throughout its history as larva and pupa, including its food-plant, 

 mode of feeding, larval case, or mine, or burrow, or mode of sewing or 

 folding leaves, mode of pupation, cocoons, &c. The case is very rare 

 that in all these respects two species approach each other so clo-ely 

 that nothing distinctive and clearly marked is left of either. Yet, rare 

 as they are, cases do sometimes occur where we are still left in doubt 

 as to the distinct specific characters even of bred specimens, as, for 

 instance, it may yet be considered doubtful whether Aspidisca splen- 

 dorij'uella Clem., A. juglandidla Cham., A. diospyrieUa Cham., and the 

 species mentioned by Mr. Staiutou as having been found by Lord Wal- 

 singham mining Poplar leaves in Oregon, are distinct species, the chief 

 reason for considering them distinct being the difference in food, it 

 being a very unusual thing to find one of these little leaf-mining species 

 feeding on so many and diverse plants. 



As to a great majority of the species, we are ignorant what they feed 

 upon or whether they feed at all in the imago. With the exception of 

 half a dozen species mentioned hereinafter, I have never seen any of 

 these little species feeding upon anything except in the larval state. 



It is to aid in the identification of species that this catalogue has 

 been prepared. A species having been bred, and the food-plant thus 

 known, and its characters as larva or pupa, and its mode of feeding, 



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