NORTH AMERICAN STENOMIDAE — DUCKWORTH 51 



and the presence or absence of white apical cUia on the forewing. 

 This species closely resembles M. melanella in both superficial 

 appearance and in structure of the genitalia; however, M. tortrici- 

 formella lacks on the costa of the forewing the white spot that is 

 present in M. melanella. The genitalia differ from those of AI. melan- 

 ella in that the cornuti in the aedeagus of the male consist of two large 

 heavy spines and the signum in the corpus bursae of the female is 

 cruciform. 



2. Menesta melanella Murtfeldt 



Figures 22, 45; Plate 4e; Map 12 

 Menesta melanella Murtfeldt, 1890, Insect Life, vol. 2, p. 304. — Busck, 1903b, 

 Proc. U.S. Nat. Mus., vol. 25, p. 903; 1934, in Lepidopterorum catalogus, 

 vol. 67, p. 5. 



Alar expanse 10-12 mm. 



Color: Face and palpus white. Legs white shaded lightly with 

 fuscous. Thorax blackish brown dorsally. Abdomen blackish brown 

 dorsally, white ventrally. Forewing blackish brown with greenish- 

 violet reflections, triangular patch of white scales on costa about mid- 

 way between base and apex; ciha brownish black, white apically. 

 Hindwing with broad white streak extending along costa from base 

 to beyond midpoint; cilia brown with patches of white near outer 

 angle and near base. 



Male genitalia: Uncus as in AI. tortriciformella except apex not as 

 sharply pointed; gnathos as in M. tortriciformella except apex, which 

 ends in a sharp point; harpes and vinculum as in M. tortriciformella; 

 anellus with two lateral lobes as in M. tortriciformella but larger and not 

 encircling aedeagus; aedeagus slightly pointed apically; cornuti con- 

 sisting of one large heavy spine. 



Female genitaha: Genital plate, ostium bursae, and ductus bursae 

 as in M. tortriciformella; corpus bursae with heavily sclerotized, rec- 

 tangular signum with median lobe; inception of ductus seminalis 

 near ostium, anterior apophyses as in M. tortriciformella. 



Type: In the United States National Museum. 



Type locality: Missouri. 



Food plant: Quercus stellata Wangh. Murtfeldt (1890) gives an 

 account of the life history of this species. 



Distribution: south Carolina: Oconee (Aug.). new jersey: Lake- 

 hurst (June). Massachusetts: Martha's Vineyard (June). Florida: 

 Dade City (April). Virginia: Falls Church (Aug.). Arizona: Ma- 

 dera Canyon, Santa Rita Mts. (Aug.). 



From M. tortriciformella, which it resembles, this species differs by 

 a white spot being present on the costal edge of the forewing, by the 

 cornuti consisting of one large heavy spine in the male genitalia, and 

 by the signum being rectangular in the female genitaha. 



