318 



THE AMEBIC AX A\ 1 TUB . I L IS T 



[Vol. LIV 



the most highly specialized. It is not rare, however, to 

 find all three types represented in otherwise very homo- 

 geneous groups. The Lepidoptera, for example, form an 

 enormous complex of species, practically all of them phy- 

 tophagous, the majority feeding upon a very, restricted 

 series of plants and representing the oligophagous habit, 

 with a smaller series of apparently monophagous forms 

 and a few secondarily polyphagous ones. Fortunately 

 also, the food habits of this order as a whole, are better 

 known than those of other insects and it can be examined 

 with less chance of error than perhaps any other group 

 of equal extent. 



As already stated, nearly all of the larvae of the Lepi- 

 doptera are phytophagous at the present time and there 

 can be no question that since the order has existed this 

 condition has prevailed. Owing to a change in the form 

 of the trophi during metamorphosis by which the adult 

 Lepidoptera develop haustellate or sucking mouthparts, 

 the food of the imagines is entirely different from that 

 of the larva? and they subsist upon liquids, mainly the 

 nectar of flowers. 



We may then classify the food-habits of the larva? 

 roughly as follows : 



Plant-food . . °° . . . . ^ Nearly all of™ 



Animal food 



