314 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 6 



The parent moths are never very active though after they have 

 emerged a day or two they are seen to fl}' about in breeding cages 

 and in the orchard during the evening. When at rest the moth takes 

 the characteristic position of other closely related moths, namely, 

 standing with the tip of the wings and the end of the abdomen touch- 

 ing the object on which it rests and with the front part of the body 

 propped up on the two front pairs of legs at an angle of 45°. 



The eggs seem to be deposited during the evening and night and 

 are placed singly on the lower side of the leaves. The egg is slightly 

 oval in outline and exceedingly small, from .25 mm. to .4 mm. in length. 

 The shell is beautifully sculptured both on the upper and lower side. 

 This sculpturing is uniform over the entire surface and is so delicate 

 that it requires very high magnification to bring it out. The sculp- 

 turing on the lower half of the shell is partially obliterated by the 

 cementing substance which attaches it to the leaf. The writer has 

 not succeeded in locating fresh eggs but from the appearance of the 

 freshly hatched eggs, they seem to be quite flat. 



Upon hatching the young caterpillar bores at once beneath the 

 epidermis of the leaf. Not infrequently this tunnel is made through 

 the lower shell of the egg. 



For the first few days the caterpillar produces a serpentine type 

 of mine which, to begin with, is not readily distinguished. After 

 three or four days the caterpillar ceases to advance farther under 

 the epidermis of the leaf and begins to eat out the cells on either side 

 of the narrow serpentine mine, thereby producing a distinct blotch 

 mine, and in three to four days more the blotch mine begins to take 

 on the tentiform shape due to the drying out of the lower side of the 

 leaf and to the tension produced by silk spun inside the mine by the 

 caterpillar. The larva, therefore, in its development begins with a 

 serpentine mine and ends with the characteristic elevated tentiform 

 mine. After the tentiform mine is once produced the caterpillar feeds 

 for a number of days upon the layer of chlorophyll cells immedi- 

 ately under the upper epidermis which causes the mine to take on 

 a more or less transparent appearance when all of the chlorophyll 

 has been removed. The mine is completed in from eight to fourteen 

 daj'^s. The young caterpillar leaves a trail of fine excrement along 

 the course of the serpentine . mine and scatters it promiscuously 

 throughout the blotch mine but in the tentiform mine it is largely 

 collected in one end and may be partly covered with silk. 



After the mine has been completed the caterpillar usually continues 

 to inhabit it for a few days after which a small round hole is eaten 

 through the lower side of the mine and the larva crawls about on the 

 foliage and on the limbs of the trees in search of a suitable place to 



