44 PROCEEDINGS OF THE NATIONAL MUSEUM vol. iie 



Genus Stenoma Zeller 



Stenoma Zeller, 1839, Isis von Oken, vol. 32, p, 195. 



1. Stenoma mistrella Busck 



Figures 16, 39; Plate 3d; Map 8 



Stenoma mistrella Busck, 1907, Proc. Ent. See. Washington, vol. 8, p. 93. — 

 Walsingham, 1913, Lepidoptera-Heterocera, vol. 4 (vol. 42 in Godman and 

 Salvin, Biologla Central!- Americana), p. 183. — Barnes and Busck, 1920, 

 Contrib. Nat. Hist. Lep. North America, vol. 4, p. 238. — Busck and Dampf, 

 1929, Estud. Ofic. Fed. Agric. Mexico, vol. 2, p. 13.— Busck, 1934, in 

 Lepidopterorum catalogus, vol. 67, p. 49. 



Alar expanse 20-23 mm. 



Color: Face white; palpus light fuscous. Legs ochreous; forelegs 

 dark anteriorly. Thorax Ught ochreous dorsally. Abdomen dark 

 fuscous. Forewing ranging from Hght ochreous, minutely speckled 

 and overlaid with darker brown scales, to uniform dark fuscous; 

 small, conspicuous, round black dot at apex of cell; costa nearly 

 straight, apex pointed. Hindwing dark fuscous; ciha light ochreous. 



Male genitaha: Uncus reduced, knoblike; gnathos incomplete in 

 front; harpes simple, somewhat pointed at apex, bearing short, stiff, 

 bifurcate setae; vinculum complete; anellar lobes broad, pointed 

 apicaUy; aedeagus large, flared apically; cornuti two clusters of very 

 heavy spines. 



Female genitaha: Genital plate small, lamella postvaginahs fused 

 medially with eighth sternite; ostium bursae large, somewhat sclero- 

 tized; ductus bursae membranous; corpus bursae with Hghtly scle- 

 rotized signum. Inception of ductus seminalis near ostium. 



Type: In the United States National Museum. 



Type locaUty: St. Louis, Missouri. 



Food plant: Phleum pratense L., bromegrass, and Kentucky blue- 

 grass. Miller (1940) reports that the larvae construct sheltered tubes 

 at the base of gxass similar to Crambus sp. and feed on the edge of 

 the neighboring grass blades. 



Distribution: Mississippi: Jackson (July, Sept.); Pearl (June, 

 Sept.). MISSOURI: St. Louis (April, July), ohio: Cincinnati (July). 

 ILLINOIS: Chicago (June); Decatur (June, Aug., Sept.); Lacon (Sept.). 

 TEXAS: Victoria (July), kansas: Onaga. Pennsylvania: Pittsburgh 

 (Sept.). NEW MEXICO: Frijoles Canyon (Sept.). Manitoba: Win- 

 nipeg. 



This species is readily separated from Stenoma crambitella by the 

 flared apex of the aedeagus in the male and by the presence of only 

 one lightly sclerotized signum in the female. 



