SUPERFAMILY TINEOIDEA 125 



seasonal life of the species is reached. Towards fall there is a 

 gradual diminution in numbers, and during October a partial 

 dying out of the species, due in great measure to the scarcity of 

 new leaves which are necessary to the successful maturing of the 

 larvae. In the neighborhood of Washington, D. C, the last larval 

 brood appears early in October. 



The eggs are laid singly on the under surface of the leaves, 

 usually near the base and between the branching ribs. They 

 average about 0.1 mm. in length, are elliptic in circumference, 

 flattened below and convex above, shining pearly white, and mi- 

 nutely faceted. The period of incubation for those specimens 

 under observation was from 4 to 6 days. 



Upon emergence from the egg the young larva makes a short 

 irregular linear mine just beneath the cuticle of the leaf on the 

 under side. In this mine it passes the first two instars during 

 both of which it is of the flat specialized gracilariid type, whitish, 

 without legs, abdominal feet or discernible body tubercles or 

 setae. 



After the larva has moulted for the second time it bores into one 

 of the branching ribs which it mines during the whole or greater 

 part of the third instar. The later instars, two of which we are 

 able to account for, are passed in the mid-rib within which the 

 larva mines up or down, as the case may be, and from which it 

 emerges when ready to spin its cocoon. As a rule the path of the 

 mine is upward, the larva emerging from the upper side of the rib 

 near the tip. In some cases where the leaf is too small for the 

 mid-rib to afford sufficient nourishment, the larva continues to 

 mine from there into the fleshy part of the leaf making a large 

 irregular blotch quite similar to that of Eriocrania. This habit, 

 however, is quite abnormal. 



The first two instars are the only ones in which the larvea are 

 of the flat gracilariid type. The third instar larva is transitional 

 between these and the typical cylindrical gracilariid form of the 

 following instars, but with pronounced affinities to the latter. 

 It is cylindrical, has well developed spinneret, labial and maxillary 

 palpi and appreciable body setae. There are, however, no no- 

 ticeable legs or abdominal feet and the head-capsule while rounded 

 inclines somewhat to the flattened wedge shape. 







