ORDER DIPTERA 245 



colored pupae within the leaf. An infested leaf may con- 

 tain twelve or more larvae. 



The European boxwood is apparently the only food plant 

 of the species. It is commonly imported from England, 

 France, and Holland. Inspectors from Washington, D. C, 

 and from various places in New Jersey and New York, have 

 intercepted the miner in making examinations of imported 

 stock. 



Thecodiplosis 



This genus includes a species, T. liriodendri O. S., which 

 has been called a leaf-miner by Osten Sacken but has been 

 included by other authorities among the gall-makers. The 

 distinction here between the mining and the gall-making 

 habit is a matter of interpretation (see p. 23). The larva 

 appears at first to cause a gall to grow and then mines out 

 the center of it. The leaf becomes spotted with brown 

 capsule-like dots 2 to 3 mm. in diameter plainly visible from 

 either side, each surrounded by a broader ring of green or 

 yellow or tan. The larva lives within the central area and 

 consumes its mesophyl. 



Family Trypetidae 



There is known in our fauna in this family but a single 

 leaf -mining species, Aoidia heraclei. It is widely distributed 

 in Europe and in America where it infests the leaves of a 

 number of herbs. 



The larvae produce irregular blotch mines. Several 

 larvae work within a single mine, thereby making it very 

 large. The epidermal layers of the leaf become separated, 

 forming a large pocket within the leaf, which is often filled 

 with considerable moisture and contains blackish frass 

 scattered about in small spots. This gives the mine a very 

 dilapidated and messy appearance. As the mine dries, it 

 becomes brownish in color and the leaf curls as though it 



