84 LEAF-MINING INSECTS 



becomes a case-bearer much earlier in life than Phylloporia. 

 Nemophora swammerdamella of Europe mines in the leaves 

 of Oak and Beech as a young larva. In late larval life its 

 case will be found to be compounded of several pieces on 

 account of necessary enlargements from time to time as the 

 larva grows. 



The known European larvae of Incurvaria are at first 

 either borers in young shoots (7. pubicornis, I. capitella, 

 I. morosa) or burrowers in buds (7. redimitella, I. rubiella) 

 or, more commonly, miners in leaves. The former habits 

 may have been derived from the latter. Adults emerging 

 very early may have come too soon for leaves, and may have 

 adapted themselves to other succulent parts. The miners 

 feed, some on Oak and Birch and some on members of the 

 rose family; the borers and burrowers seem all to be at- 

 tached to the Rose Family. Early in life (except /. capitella) 

 they one and all begin to wear a case; the miners cutting 

 case from the leaf as do Phylloporia and Nemophora. In 

 their cases they travel about on their [host plant or the 

 ground, eating living or dead leaves. When their first case 

 is outgrown, they meet the emergency by fastening one side 

 of their bivalve case to a leaf and cutting out a piece which 

 is shaped like the first but bigger. Then they turn the case 

 over and do as much for the other side. When the larvae are 

 full-fed, their cases will be found to consist of two valves 

 made of several discs of leaf arranged concentricly, with the 

 smallest next to the larva. From these cases the larvae 

 feed from the end of the mining period in late June until 

 they pupate in September or October. 



