Rhabdorthodes durango, Crabo, Lars G., 2018

Crabo, Lars G., 2018, A new genus and three new species of noctuid moths from western United States of America and Mexico (Lepidoptera, Noctuidae, Noctuinae, Eriopygini), ZooKeys 788, pp. 183-199 : 188-192

Rhabdorthodes durango sp. n. Figs 5, 8, 11, 14, 16

Type locality.

Mexico: Durango: 16 km west of El Salto, 2743 m.

Type material.

Holotype, male. Mexico: D[uran]go: 10 mi. [16 km] W El Salto, 9000' [2743 m], 8 VIII 1964, J. E. H. Martin. / Specimen ID CNCLEP 00140425 / Genitalia CNC slide # 17405 male. CNC. Paratype. 1 male, 1 female. Same locality as holotype, 9 VIII 1964, W. C. McGuffin / Genitalia CNC slide 15892 male (1 male); same label data as last / Genitalia CNC slide 17437 (1 f). CNC.

Diagnosis.

This species and R. petersoni sp. n. are closely similar and cannot be distinguished reliably by superficial appearance. Both are more strongly patterned and have more luteous filling of lines and stigmata on the forewing than R. pattersoni . In practice, location provides a convenient diagnostic character since it is likely that all three species are allopatric. Rhabdorthodes durango sp. n. is the only species that is known from the Sierra Madre Occidental, Mexico.

Structurally, males of R. durango have the largest and most complex distal clasper in the genus, with a blunt curved ventral process that extends ventral to the valve and a molar like mesial process that projects over the distal valve. By comparison, the distal clasper of other species is much smaller ( R. pattersoni ) or lacks the broad mesial process ( R. petersoni ).

Females of R. durango can be identified by the shape of the concave ventrolateral sternite A7 (Figure 14). The concavity is similar to that of R. pattersoni in that it lacks a transverse sulcus, but the lateral edge of R. durango is rounded rather than quadrate. The lateral edge is shaped like the pinna of a human ear.

Description.

Adults.Head. Male antenna total width 3 × shaft; dorsal scales dark gray-brown, occasional off-white on basal third. Labial palpus scales dark gray-brown, occasional off-white. Frons brown; dorsal head scales long, thin, mostly forked, dark gray-brown with pale bases and tips.

Thorax. Dorsum scales similar to dorsal head, appearing uniform dark gray-brown; venter darker. Legs: Scales dark gray brown, few off-white; tarsal segments darker brown ringed distally off-white. Wings: Forewing: Length 14 mm (male); 15.5 mm (female); dorsal scales nearly uniform dark gray-brown, costa black-brown; costa spots dark ochre-gray; short white veins segments: A1+A2 in proximal medial area, several in subterminal area; basal, antemedial, and postmedial lines double, black and dark-gray brown, filling paler brown-gray; basal line near wing base, indistinct; antemedial line slightly irregular, perpendicular to wing; medial line very faint, evident on anterior ⅓; postmedial line indistinct, scalloped weakly, evident on costa and posterior to reniform stigma; subterminal line ochreous off-white, irregular, patchy, strongest between branches of medial vein, preceded where strongest by ill-defined triangular black spots; terminal line thin, black, small pale spots on tips of veins; fringe ground color, edge slightly paler; claviform stigma small, black, pale filling like adjacent antemedial line; orbicular stigma nearly round, black, pale brown gray peripherally, ocellus black; reniform stigma moderately large, figure-8 shaped, black, lacking anterior and posterior outline in HT, posterior in PT, filling similar to orbicular medially, luteous laterally, ground color centrally. Hindwing: Dorsum dull medium fuscous, slightly paler on basal ½; veins and indistinct discal spot darker, faint; terminal line thin, black; fringe base dark gray, distal lighter ruddy gray.

Abdomen. Male genitalia (Figure 8): Uncus length 0.5 × juxta height. Juxta length 2.2 × width, rod length 1.5 × juxta. Valve length 4.3 × width, segment distal to clasper diminutive, curved slightly ventrad; cucullus very weak, rounded; sacculus length 0.6 × and width 0.8 × valve; distal clasper 1.2 × valve width, right slightly larger than left, thick, mesial surface with molar like ridges, dorsal margin expanded slightly at ampulla base, mesial lobe broadly triangular, oriented distad along valve axis, ventral process horn shaped, curved 90° distad; ampulla of clasper stout, directed 30° basad, distal ampulla hook shaped with 120-180° curve distad; digitus small, thin. Phallus and vesica as in genus description. Female genitalia (Figs 11, 14): Ventrolateral sternite A7 concave, deeper than in R. pattersoni , lateral margin rounded with raised flange similar to the dorsal helix of a human external ear; posterior margin thicker and more strongly convex than in R. pattersoni , less than in R. petersoni . Papilla analis, segment A8, and bursa copulatrix as in genus description; ostium bursae sclerotized with median cleft.

Etymology.

The species name refers to the type locality in the state of Durango, Mexico. It is a noun in the nominative singular in apposition to the generic name.

Distribution and ecology.

Rhabdorthodes durango is known only from the type locality near El Salto in the Sierra Madre Occidental (Figure 16). The area is reported to be open pine-oak forest (D. Lafontaine, pers. Comm.). All three specimens were collected on consecutive days in early August. The early stages are unknown.

Remarks.

This species was found by J. Donald Lafontaine amongst unsorted Mexican material at the CNC. Although the type locality is nearly 950 km south of Arizona, it is conceivable that R. durango could occur on higher mountains in the Madrean Archipelago ecoprovince of south-eastern Arizona, the northernmost extension of the Sierra Madre Occidental. Many of the species collected in this CNC survey near El Salto occur in the mountains of southeastern Arizona (D. Lafontaine, pers. Comm.).