AMERICAN LEP1DOPTERA. 21 



Hydroet'ia immaii i*> Gn., pi. 1, fig. 9, % genitalia. 



1852. —Gn., Spec. Gen. Noct., i, 128, Hydrmcia. 



1856.— Wlk., Cat, Brit. Mus. Het„ ix, 162, Hydrceeia. 



1874.— Grote, Bull. Buff Soc. Nat. Sei., ii, 18, Gortyna. 



1882. — Dodge, Can. Ent., xiv, 93, larva on Hop. 



1884.— Smith, Bull. 4th Div. Ent. U. S. Dept. Agl., 38, larva. 



1885.— Lintner, 2d Rept. Ins. N. Y., 41, larva. 



1893.— Smith. Bull. 44th U. S. Nat. Mus.. 175, Hi/drcecia. 

 Ground color dull yellowish brown, with a tendency to smoky. Collar with a 

 central pale line and a pale line at tip. In some specimens a pale line also 

 extends obliquely across the patagire. The markings of the primaries are dis- 

 tinct, as a whole paler than the ground color; the defining lines a darker shade 

 of brown or tan. Basal line geminate, extending to the submediau vein ; the 

 included space pale, the inner line fairly well marked, the outer rather diffuse. 

 T. a. line geminate, the included space paler, the defining lines well marked, as 

 a whole upright, very even, except for a slight inward bend in the cell. T. p. 

 line geminate, included space pale, the inner defining line well marked, the outer 

 rather defined by the differences in shade than in any other way. The line is 

 abruptly bent on the costa over the reniform and then is almost evenly oblique 

 inward to the inner margin. S. t. line blackish, distinct, a little irregular, broken 

 only near the apex which is somewhat paler. The median shade is fairly well 

 marked in most specimens, and is a little curved between the ordinary sp;>ts. 

 Orbicular oval, almost upright, a little paler than the ground color, very often 

 incompletely outlined. The reniform is large, upright, kidney shaped or a little 

 constricted centrally, a trifle paler than the ground color, except that it is infe- 

 riorly sometimes a little darkened. There is a smoky brown line at the base of 

 the fringes. The claviforin is small, not visible in all the specimens; but some- 

 times dark filled so that it becomes quite a recognizable feature in the wing. 

 Secondaries smoky, yellowish, darker in the female, with a dusky followed by a 

 paler median line. There is a narrow dusky line at the base of the fringes. 

 Beneath powdery, a little more reddish than on the upper surface; both wings 

 with a more or less well-defined outer transverse line, the secondaries sometimes 

 with a small discal spot. Expanse 1.50-2 in. ; 37-50 mm. 



Hub. — Northern United States to Iowa, South to Virgina ; Colo- 

 rado. New York and Illinois in August and September. 



This is one of the largest species of this series, and at the same 

 time most simple in markings. It resembles in general the Euro- 

 pean micaeea, but is a larger species, and the antenna? of the male 

 have the joints feebly marked aud with very small brush-like tufts. 

 There is no variation in the series before me, and nothing of anv 

 consequence in the species — so far as I have seen. The male geni- 

 talia have a rather long, narrow, bent tip which is fringed with 

 spinules. There is a long, curved, semi-cylindrical clasper from the 

 upper side near base, and there are two small, claw-like processes 

 from the inferior margin a little beyond the middle. The larva of 

 this species attaks the crown of hops and it is of some economic 

 importance. 



TRANS. AM. ENT. SOC. XXVI. MAY, 1899. 



