54 



species the popular name of "The Unspotted Tentiform Mine 

 of the Apple," and states that it is common about Ithaca, but not 

 sufl&ciently abundant to be seriously injurious. He remarks that 

 when the larvae are nearly mature, they leave the old mines and 

 make new ones. The latter operation is described as follows: 



"Quite a dense but still very transparent covering is spun on the 

 under side of the leaf. * * * While weaving these threads 

 from side to side over the space to include the so-called mine, the 

 larva rests on the threads already spun. In this way the larva 

 may by its weight aid in causing the mine to assume its tentiform 

 shape. When this covering is completed, the larva crawls in be- 

 tween it and the leaf, and completes the mine from the inside, by 

 spinning more threads from side to side, and drawing the edges 

 of the mine very close together. The under surface of the mine 

 thus becomes more opaque from more silk being spun there and 

 also as the silk itself, which is at first white, becomes brown." 



Concerning the later history of the larva, Mr. Brunn continues: 



"Soon the larva commences to feed, beginning at one end of the 

 mine, and eating everything clean as it goes, excepting the small 

 veins and upper epidermis. AVhen through eating, or when all 

 the parenchyma in the mine is eaten, the larva leaves the mine 

 by an opening which it makes in the under surface, and either 

 pupates in another portion of the same or a different leaf; or, if 

 not through feeding, it makes a new tentiform mine on the disk 

 of the leaf, or turLs over the edge of the leaf, and feeds on the 

 infolded portion. * * * The larvae deposit the small, rounded 

 pellets of frass in an irregular heap at one end of the mine. 



"When about to pupate the larva leaves the mine through a 

 small circular hole which it makes at one end and on the under 

 surface of the mine, goes to some portion of the edge of the leaf, 

 either on the upper or lower surface (very seldom on the lower), 

 folds the edge over itself, bringing it close down to the surface 

 of th^ leaf by silk, and then spins around itself, in this roll, a 

 delicate silken cocoon. Within this cocoon it casts its larval skin 

 and tranforms to a pupa, remaining in that condition throughout 

 the winter. It takes less than twenty-four hours for the larva to 

 make the roll within which it pupates. In exceptional cases the 

 larva will spin its cocoon in the fold of the leaf caused by its 

 mine, and at some distance from the edge of the leaf. Often the 

 larva goes to the very tip of the leaf, and brings the two edges 

 together, making its cocoon within this fold. The pupae I have 

 collected as early as October 3 and the larvae as late as October 26. A 

 young white larva which I collected November (), turned gray upon 

 Ijlacing it in alcohol. In the spring the pupae transform to dark 

 steel-gray moths, which, when at rest, assume the position shown 

 in PI. I., Fig. 2a." 



