SUPERFAMILY TINEOIDEA 



139 



Out of the vast array of forms with which we might illus- 

 trate this great genus, we will select three only, two having 

 cylindric (first group) and one having flat (second group) 

 larvae. 



The maple leaf-miner, Lithocolletis lucidicostella, makes 

 mines that are typical of the first group. In the three sap- 

 feeding instars the larvae separate the cuticle of the under 

 side of the leaves unless delimited by large veins are rounded 

 or oval. The rounded mines are but a centimeter and a 



Fig. 44. Mines of the maple leaf -miner Lithocolleles lucidicostella, with 

 central blackish frass pile. Earlier flat mines shown at A ; later tentiform 

 mine shown at B. 



half in area. In the fourth and fifth instars the larvae spin 

 silk upon the separated cuticle making the mine somewhat 

 tentiform and pick out the parenchyma from the exposed 

 tissue of its arched side. Beginning at the extreme periph- 

 ery of the mine the larvae clean the green tissue from each 

 interstice between the small veins separately and completely 

 as they go and the cleared area is a succession of tiny lattice- 

 like squares. The frass of this period of feeding is collected 

 into a rather firm ball toward one side of the mine. Its mass 



