Euros osticollis Troubridge

Troubridge, J. T., 2006, A review of the genus Euros Hy. Edwards (Lepidoptera: Noctuidae: Apameiini) with description of one new species, Zootaxa 1308, pp. 63-68 : 65-67

Euros osticollis Troubridge , new species

( Figs. 2 , 5 )

Diagnosis. Euros osticollis is easily separated from the other two Euros species by the bone white color of its head and prothoracic collar (rusty brown in the other species). The hindwing is gray brown, as in E. proprius (medium brown in E. cervina ), but the fringe is gray, not red as in E. proprius . In the male genitalia, the digitus is much narrower than those of the other species and the ampulla is very narrow.

Description. Forewing length 8–9 mm. Male antenna filiform, ciliate; eye orbicular, bare; head, palpi and prothoracic collar bone white; thorax and tegulae bone white, bordered with rust colored scales; abdomen light gray brown. Dorsal forewing ground color rusty brown; orbicular spot circular, yellow with rusty brown center, edged thinly with dark rust; reniform spot similar in coloration to orbicular spot but more completely filled with yellow scales; antemedial line dark rust, edged proximally with white scales; mesial band light rust; obscure median line dark rust; postmedial line dark rust proximally, white distally; light yellow subterminal line serrate, area distal to subterminal line rust colored with area proximal to this line lighter rust; marginal line dark rust; fringe a mix of gray brown and reddish scales. Dorsal hindwing even dark gray brown; fringe pale gray brown with darker median line.

Male genitalia ( Fig. 5 ). Costa of valve broadly sclerotized in basal two thirds, bending dorsally to form sclerotized claw. Digitus arises as small spine on fleshy mound below this claw. Small, fingerlike ampulla arises on dorsal margin of clasper near costa. Apex of clasper spinelike, pointing toward tip of valve, terminating below costal process. Uncus narrow with pointed tip. Juxta with lateral sclerotized arms extending onto annulus. Vesica bending ventrally and narrowing to ductus seminalis with subbasal dorsal diverticulum; large lateral subapical cornutus projecting anteriorly and curving dorsally from large sclerotized base; basal plate with saw­teeth on base anteriorly. Female genitalia unknown.

Type material. Holotype male: USA, Oregon, Josephine Co., Illinois River, 42°45' N 123°41' W, 3 August 1998, J. Troubridge (JTT). Paratypes: Oregon: 3 males, same data as holotype; 2 males, Josephine Co., Illinois River, 8 Dollar Mtn., 4 August 1995, J. Troubridge; 13 males, Josephine Co., 8 Dollar Rd., 42°14' N 123°40' W, 1500', 27 July 2001, J. Troubridge; 4 males, Josephine Co., 8 Dollar Rd., 42°14' N 123° 41' W, 1125', 29 August 2002, J. Troubridge. Paratypes in the CNC and JTT.

Derivation of the name. The name refers to the bone color of the prothoracic collar, a distinctive characteristic of this species.

Distribution and habitat. Euros osticollis occurs along streams and seeps in association with Darlingtonia californica Torr. (Sarraceniaceae) in southwestern Oregon. The larval host plant is unknown, but the presence of Darlingtonia in a wetland indicates the proper habitat for this species.

Figures

FIGURES 1 – 3. Adults of Euros species. 1, E. proprius, Plumas Co., California; 2, E. osticollis, Josephine Co., Oregon; 3, E. cervina, Curry Co., Oregon.

FIGURES 4 – 6. Male genitalia of Euros species. 4, E. proprius; 5, E. osticollis; 6, E. cervina.