20 



THE CANADIAN ENTOMOLOGIST. 



yellow. Abdomen dark purplish above, paler beneath in the 

 female. 



Expanse: 3.5-4 mm. 



Three specimens, Cincinnati, O., two bred from mines on 

 swamp white oak (Quercus platanoides (Lam.) Sudw.) the other on 

 pin oak (Q. palustris Du Roi.) The mine is a very characteristic 

 linear tract. The egg is placed on the upper side of the leaf and 

 the larva for the first few millimeters mines near the upper surface, 

 making a very narrow indistinct mine. Then the mine abruptly 

 enlarges slightly and for a length of 8 or. 9 mm. the leaf substance 



is entirely consumed and the mine 

 rendered transparent. Then follows 

 another enlargement, and the mine, 

 often much contorted, increases very 

 gradually in breadth to the end, 

 where it measures 2 mm. across. 

 This latter portion of the mine is not 

 transparent. The frass is sprinkled 

 in separate grains across the entire 

 breadth of the mine. The accom- 

 panying figure shows the appearance of the mine when held toward 

 the light. While most commonly found on pin and swamp white 

 oak, the mine occasionally occurs on red and scarlet oaks. There 

 are three generations a year: mines can be collected during early 

 June, the latter half of July, and the early part of September. The 

 larva is usually green, occasionally purplish and escapes from the 

 mine through the lower surface of the leaf. The cocoon is almost 

 white, woven of coarse rough silk. 



The moths are almost indistinguishable from specimens of iV. 

 rastanecefoliella Chambers; the only constant difference I have 

 found to separate them is the yellow colour of the middle and hind 

 tarsi of N. flavipedela in contrast with the sordid white tarsi of 



N. castanecefo/ieUa. 



Types in my collection. 



Nepticula chalybeia n. sp. 



Palpi grayish ocherous. Tuft ocherous, collar yellowish white. 

 Antenna? fuscous, eye-caps yellowish white. Thorax steel-gray. 



Fig. 4. — Mine of 

 V. fLivipedclla . 



