CHAPTER VIII 



SUPERFAMILY CyNODIOIDEA 

 FAMILY CYCNODIIDAE 



The grass miners 



This is a small family whose larva mine in the leaves of 

 the coarser grasses and grass-like plants (sedges and bul- 

 rushes). Most species appear to be single-brooded and to 

 reach maturity in spring or early summer. From March 

 to May is the best season for finding them. They over- 

 winter as young larvae or as eggs. The mines of those that 

 begin activity in autumn are formed in leaves that later 

 are winter killed; so, in the spring they enter other leaves 

 and make new, and generally larger mines. The mines 

 usually extend from the leaf tip downwards, and naturally 

 they are linear, conforming to the shape of the leaves; but 

 they widen into more or less of a blotch, with the detached 

 epidermis either smooth or wrinkled in the later stages. 

 The pupa is found outside the mine, attached to the leaf, 

 either naked or suspended in a few tangled threads of silk. 



The white hystrix miner, Aphelosetia orestella, is a common 

 representative of the group. According to Miss Braun (20 

 and 21) it mines the basal overwintering leaves of the grass 

 Hystrix patula, and when these leaves are frozen it transfers 

 to mine new leaves in the spring. The mine extends from 

 the tip of the leaf blade downward, broadening somewhat 

 below. At about the middle of the grayish mine the epi- 

 dermis is wrinkled, drawing the leaf into a fold. In color 

 it is grayish, as is also the grown larva found within it in 

 the spring. The pupa is not inclosed in a cocoon, but 

 attached flat to the leaf, with head upward. 



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