LEPIDOPTERA OF NEW YORK AND NEIGHBORING STATES 83 



Key to species 



a. Fore wings unicolorous 1. populella. 



aa. Fore wings mottled. 



b. Dark-tipped scales evenly distributed 2. castanece. 



bb. Dark-tipped scales more or less collected into patches. 



c. Base of fore wing with scattered dusting, except near costa..5. obrutella. 

 cc. Dusting dense near base of wing. 



d. A poorly defined, pale fascia at basal third 4. heinrichi. 



dd. No fascia at basal third 3. phleophaga. 



1. E. populella Busck. Tuft reddish ocherous, eye -caps pale yellowish. Fore 

 wings shining coppery brown, with green and violet iridescence. 78 . 5 mm. 



The larvae form almost globular galls, of the size of a pea, on the petioles of 

 leaves of poplar. The larva is full-grown in October. The moth appears in May. 



2. E. castaneas Busck. Tuft black above; eye-caps creamy -white. Fore wing 

 clothed with bluish white scales, which are mostly deeply tipped with blackish 

 brown, so that the wing is almost uniformily densely dusted. 7.5-8 mm. 



The larvae form cylindrical galls encircling young twigs of chestnut. 



3. E. phleophaga Busck. Tuft ocherous. Thorax and basal half of fore w r ing 

 dark bluish fuscous, outer half paler, bluish with dark-tipped scales; an ill- 

 defined, ocherous costal and an opposite dorsal patch at apical third. 9-10 mm. 



Serpentine mines in bark of chestnut: larva full grown in April and May; 

 imago in September. 



4. E. heinrichi Busck. Tuft black, eye-caps creamy-white. Fore wing pale ocher- 

 ous, densely dusted with blackish fuscous scales, which tend to form patches. 

 The dark dusting is usually absent or scattered at the extreme base of wing 

 "vcept along costa and on two poorly defined, transverse fasciae, one at basal 

 third, the other at apical third; the second fascia sometimes almost obliterated 

 by dusting. 9-10 mm. 



The larva forms a characteristic, flattened-oval, spiral mine in the bark of young 

 branches of pin oak (Quercus palustris). The larva? are full-grown in October 

 and early November, producing moths in May and June of the following year. 



5. E. obrutella Zeller. Differs from the two preceding species chiefly by the 

 scattered dusting of the basal half of wing. Food plant unknown, thus far 

 recorded only from Texas. 



4. NEPTICULA von Heyden 



Basal segment of antennae dilated and concave beneath to form a large eye-cap. 

 Middle spurs of posterior tibiae in or above the middle. Fore wings elongate 

 ovate, pointed; hind wings one-half to two-thirds as wide as fore wings. Fore 

 wings ( figs. 52, 53, 56 ) ; media coalescing with radius from base to beyond middle 

 of wing, or coalescing with cubitus at base and passing obliquely to radius 

 beyond R, +3 and anastomosing with radius to beyond middle of wing as before. 

 R, sometimes coincident with R 5 . Media single -branched. Cubitus usually reach- 

 ing nearly to margin. Hind wings : media single-branched. 



As far as is known, the larvae of all of the North American species are miners 

 within the tissues of leaves. The egg is placed on either the upper or under sur- 

 face of the leaf, often along the side of a vein, and the larva passes directly into 

 the interior of the leaf. The larva usually mines just beneath the upper epider- 

 mis, consuming the palisade layer of cells, and in later stages, some of the spongy 

 parenchyma cells. In thin leaves, the mine seems more transparent, because of 

 the originally smaller number of these cells and the looseness of their arrange- 

 ment. Where the upper or lower surface is mined indiscriminately, as is done by 

 N. populetorum in the leaves of poplar, the cross section of the leaf shows palisade 



