REPORT OP THE ENTOMOLOGIST. 231 



being separated by the iniuing larva, slirinks as it dries, tlins throwing 

 the opposite side, of the leaf into a projecting fold. The mine is thus 

 more roomy, and we should expect to find in it a larva which is not so 

 flat as tliat of the white blotch oak-leaf mine, and such Is indeed the 

 case. 'When the njino is made along the edge of a leaf, this contracting 

 of the under skin causes the edge to tiun over in such a way that, at a 

 casual glance, it much resembles the work of a Tortricid or leaf-rolling 

 larva. The color of the mine is a dirty yellow. While the larva is yet 

 young it does no more than separate the under cuticle from the paren- 

 chyma, so that for some time the mine is not noticeable from the upper 

 side, except from the elevation caused in the manner just described. 

 When, however, the mine has become of sufficient size to afford it a 

 comfortable working place, the now half-grown larva attacks the paren- 

 chyma, eating all but the upper epidermis and the stronger veins. This 

 is done at first around the edges of the mine as laid out, but gradually 

 the work advances inward to the center until all, or nearly all, is eaten, 

 and the surface of the leaf above the mine presents a skeletonized ap- 

 pearance. Frequently, however, the larva attains full growth before 

 this is completely accomplished, and from this fact mines are often found 

 which, when seen from above, appear simply as a skeletonized circular 

 band, inclosing a normal green center of greater or less size. 



The full-grown larva is between 4""" and 5""° in length (from .15 to .19 

 inch). It does not belong to the so-called "fiat" group of Lithocolletis 

 larvae, but rather to the "cylindrical" group, and, consequently, does 

 not present such abnormalities of structure as we have seen in the larva 

 of L. JiamadryadeUa. The mouth parts are normal, the thoracic legs are 

 large and well developed, each being armed with a terminal claw, the 

 prolegs are present in normal number and normal position, though 

 rather small, and the whole appearance of the larva is such that at a 

 glance it would be called lepidopterous. The general color is nearly 

 white, the mouth parts being tipped with brown, and there is no ap- 

 pearance of the darker horny shields which gives the flat larvae so 

 characteristic an appearance. The anterior (thoracic) segments of the 

 body are larger than the others, and the head is retractile within the 

 first. The abdominal joints are of nearly uniform size. Over the sur- 

 face of the body are scattered a few long white hairs. The excrement 

 of L. Fitchella, for some unexplained reason, seems to differ in character 

 from that of L. hamadryadella. In the case of the latter, as we have 

 already stated, the whole floor of the mine is spotted with the firass, 

 which seems to have been smeared on when very moist, and, <lrying, 

 has become hard and black. In old mines in which more than one 

 larva has been at work the floor is covered with what looks like a thin 

 sheet of cracked black enamel. With L. Fitchella, however, the excre- 

 ment consists of minute, dry, hard pellets, which are collected togetlier 

 in some one part of the mine, leaving the floor perfectly clean. The 

 cast-off skins of the larva are also to be found in this ball of pellets. 



When the larva prepares for pupation it spins no regular cocoon, as 

 does L. hamadryadella, but simply weaves a network of fibers back and 

 forth from one side to the other of the mine. Then stationing itself in 

 the midst of this mesh of silken fibers, supported on aU sides without 

 touching the walls of the mine, it c^jists its last larval skin ; the quantity 

 of sdk thus spun varies greatly with different individuals," some spin- 

 ning enough to form an irregular and delicate oval cocoon, others hav- 

 ing almost no silk in their mines. The color of the silk varies from white 

 to light brown. 



The pupa is of a very light brownish-yellow color at first, but just 



