SUPERFAMILY TINEOIDEA 135 



soft leaf tissue, one face of which was sheared free from the 

 epidermis in the earlier sap-feeding instars. They thus 

 complete the removal of this tissue, without much altering 

 the outer borders of the mine; and often during three later 

 instars they feed from the periphery toward the center, and 

 bestow their granular frass at the outer edges. 



The larva of the second or flat (Cameraria) group, in the 

 fourth and fifth instars, instead of picking out parenchyma 

 from already exposed tissue, continue to extend their mines, 

 now by cutting out thin sheets of tissue beyond the former 

 periphery. They are peculiar in having seven instars, of 

 which the last two are non-feeding stages in which the lar- 

 vae merely prepare for pupation. 



The mines made by the larvae of the first group may be 

 oval, or circular, or nearly rectangular, bounded by veins. 

 In removing the parenchyma most of the larvae feed from 

 the circumference inwards. Some begin at one end and 

 work toward the other, and some, as L. crataegella on apples, 

 pick it out irregularly in spots. The frass of the tissue-feed- 

 ing instars may be collected into a ball, or scattered about 

 tidily around the periphery of the mine. 



All the larvae in this first group pupate in the mines 4 

 and may or may not first enclose themselves in cocoons. 

 In the species in which no definite cocoon is made, the pupae 

 may be suspended by a thin meshwork of silken threads as 

 in L. fitchella, L. argentifimbriella, L. clemensella and L. 

 lucidocostella, or the part of the mine containing the pupa 

 may be sparingly lined with silk, as is the mine of L. mar- 

 tiella. The naked pupae of L. populiella are said to be 

 attached by their anal ends to a button of silk on the roof 

 of their mines. When a more definite cocoon is made it 

 may be large and loosely woven, taking up nearly half of 

 the mine in the case of L. albanotella and L. robiniella, 



4 Excepting only (so far as now known) L. ostensackenclla. 



