April, 1921] Notes on Elachista—II 209 



Elachista leucofrons Braun. 



By some confusion of data which I can not now explain, the 

 mine and larva described as belonging to this species (Ohio Jn. 

 Sci., XX, 170, 1920) belong to Elachista orestella, in which the 

 larva is either grayish or green and marked as described. The 

 mine of Elachista orestella is grayish, with epidermis wrinkled 

 in the middle of the length of the mine, which here only is 

 green. 



The mine of E. leucofrons is whitish, with epidermis nowhere 

 wrinkled; the mine lies just beneath the upper epidermis, 

 extending usually across the leaf; the underside of the leaf 

 remains green. The mine occurs on both Hystrix and Elymus, 

 most commonly on the latter grass, while that of E. orestella 

 occurs most commonly on Hystrix. The larva of E. leucofrons 

 is pale grayish or greenish, with narrow mid-dorsal and broad 

 lateral lines whitish; first segment of thorax marked posteriorly 

 by a transverse brownish mark, curving forwards at each end. 



Elachista irrorata Braun. 



The larvae of this species commonly mine leaves of Glyceria 

 nervata, a tall grass occurring in moist meadows and wet places. 

 The larva mines toward the tip of the leaf, the narrow indistinct 

 pale yellowish green mine usually beginning low down on the 

 leaf sheath, where the larva lies concealed during the day. 

 The larva sometimes makes a short detached -mine near the 

 tip of the leaf; such mines are always untenanted in day time. 

 Even when the larva is full grown, the mine is scarcely wider 

 than the body of the larva. Mines were collected from the 

 middle of April to the early part of May; the imagoes emerged 

 from May 19 to June 10. Larva yellow when young, glaucous 

 above when full grown. 



The pupa is always attached near the base of the leaf on the 

 upper side with head pointing toward the stem. The pupee may 

 easily be collected on the food plant at the proper season. The 

 pupa, which shows a general resemblance to that of E. leuco- 

 frons, has a broader mesothorax with more tubercles, the 

 median ridge of the abdomen more depressed, the lateral ridges 

 projecting farther. 



