Elachista praelineata Braun 1915

Elachista praelineata Braun (Figs. 30, 44, 99, 99a, 134, 134a, 134b.)
1915. Elachista praelineata Braun, Canad. Ent., xlvii, 106. Type 2, Cincinnati, Ohio [A. F. B. Coll.].
1916. Elachista praelineata Mosher, Bull. 111. State Lab. Xat. Hist., xn, Art. 11, p. 106, PI. xxvi, fig. 100.
1923. Aphclosetia praelineata Forbes, Mem. 68, Cornell Univ. Agric. Exp. Sta., p. 222.
Face pale gray, darker speckled, head gradually darkening to grayish black posteriorly ; palpi dark fuscous beneath, paler above with tip of second segment, a broad band and extreme tip of third segment blackish, these markings more sharply defined in the female. Antennae black with paler annulations, last one or two segments pale. Thorax black, with tips of tegulae and mesothorax white. Fore wing, venation typical ; black ; from base of costa to dorsum narrowly white with a slight yellowish tinge ; before middle, a curved white fascia, narrow in male ; at tornus, a triangular white spot, and nearly opposite on costa, a similar costal spot. Apical row of scales black and sharply contrasting with the cilia which are white around apex, dark gray elsewhere. Hind wing, M 3 absent ; dark gray. Legs black, inwardly silvery ; tarsal segments white-tipped, hind tibiae with the median silvery band broad. Abdomen dark fuscous above, silvery beneath, the dense abdominal tuft of the female pale yellowish gray, with a greater or less admixture of dark gray in the median line.
Alar expanse : 6.5 to 7.5 mm.
Male genitalia (figs. 99, 99a) : uncus lobes widely separated, incurved, sinus quadrate ; gnathos ellipsoidal ; harpe extremely narrow and long, with cucullus greatly reduced, sacculus process a slender rod ; lobes of anellus slender, curving to the pointed tips; aedeagus bifid at tip, cornuti a mass of microscopic spines.
Female genitalia (figs. 134, 134a, 134b) : genital segments largely membranous; lobes of ovipositor pointed; bursa copulatrix small, smooth, without signum ; ductus bursae membranous throughout, abruptly dilating to the wide ostium, which is minutely spiculate dorsally and sclerotized on its ventral margin only. Seventh tergite with sclerotized plate bearing a dense mass of knobbed hairs, with four clusters of still more densely packed hairs (figs. 134a, 134b).
Specimens examined: 5 $, 8 2.
Ohio: Cincinnati, 2 type, under rearing record B.836, imago August 8, 1914; 3 <$, 4 9 paratypes, B.836, with dates of emergence August 2 and 4, 1914 [A. F.' B. Coll. and U. S. N. M.] ; 2 8, 2 2 , rearing record B.836, with dates of emergence July 31 to August 6, 1919 [A. F. B. Coll.] ; 1 2, rearing record B.1016, imago September 2, 1919 [A. N. S. P.].
The larva is a miner of leaves of Hystrix patitla Moench. (and rarely of Elymus) in July. By a twist of the petiole, the true upper side of the leaf of Hystrix faces downward; the following description of the mine, and the figure (fig. 30) give the aspect as seen in the field, viewing what is in fact the lower side of the leaf. The early mine is a narrow line scarcely visible above ; it gradually enlarges into an elongate blotch, with the greatest width about 4 mm. ; except in the widest portion of the mine, the parenchyma is only consumed adjacent to the true upper epidermis and the mine as seen from above is green ; even in the blotch, patches of green tissue remain. Below, the mine is whitish and distinctly visible throughout ; the tissue adjacent to the true upper epidermis has been completely consumed. The specimens under B.836 were reared on Hystrix, the single specimen under B.1016 on Elymus, all from the same locality in a dry hillside woods.
Pupa (fig. 44) shining, attached at anal end and by a median girdle and covered by a few criss-cross silken threads. Vertex and prothorax strongly tuberculate, the usual mesothoracic tubercles prominent, with additional associated small tubercles; wings with lines of small tubercles.
In general appearance, E. praelineata resembles E. leucojrons, but is easily distinguished from it by the smaller size, reduced venation of the hind wing, early stages and genitalic characters; the last definitely place it in the radiantella group.