USA: Colorado: Clear Creek County: Doolittle Ranch, Mt. Evans, 2987 m.

Holotype, male. USA: Colorado: [Clear Creek County]: Doolittle Ranch, Mt. Evans, 9,800’ [2987 m], 10 VIII 1961, E. W. Rockburne. / Specimen ID CNCLEP 00140423. CNC. Paratypes. 49 m, 5 f. USA: Arizona: Apache County: Alpine, 3–5 mi [4.8–8.0 km] SE, 16 VI 1967 (1 m); Greer, White Mts., 8500’ [2591 m], 6 VIII 1962, E. & I. Munroe, black light (1 m); same collection label / Genitalia slide # 11,732 male (1 m); [Greenlee County], Hannagan Meadow, 13 VI 1967, R. F. Sternitzky / Genitalia CNC slide # 17406 female (1 f); same collection label / [CNC] Slide No. 11,734 (1 m); Colorado: Archuleta County: [north of Pagosa Springs], 8[000]’ [2438 m.], 15 VI 2004, Vargo leg. / Specimen ID CNCLEP 00120092 (1 m); same collection label / Specimen ID CNCLEP 00120092 (1 f); [Boulder County]: Boulder, Silver Saddle Motel, 5500’ [1676 m], 5 VI 1961, M. R. MacKay (1 m); [Clear Creek County]: Doolittle Ranch, Mt. Evans, 9800’ [2987 m], 16 VII 1961, E. W. Rockburne / Genitalia CNC slide # 15894 male (1 m); same collection label, 30 VII 1961 (1 m); same collection label / [CNC] Slide No. 10,766 female (1 f); same locality & collector, 31 VII 1961 (4 m); same collection label / [CNC] Slide No. 10,764 male (1 m); same locality & collector, 1 VIII 1961 (8 m); same locality and collector, 2 VIII 1961 (6 m); same collection label / Genitalia CNC slide # 15893 male (1 m); same locality & collector, 3 VIII 1961 (1 m); same locality & collector, 5 VIII 1961 (1 m); same locality & collector, 6 VIII 1961 (1 m); same locality & collector, 6 VIII 1961 (1 m); same locality & collector, 8 VIII 1961 (1 m); Teller County: Florissant, 3.5 mi [5.6 km] SW, 38.904° -105.323°, 8–9 VII 2016, 2660 m, L. G. Crabo & G. Morrell leg. (4 m); Idaho: Bear Lake County: Georgetown Cyn., 42.524° -111.263°, 2100 m, 4 VII 2016, L. G. Crabo & G. Morrel leg. / Specimen ID CNCLEP00140350 / Barcode of Life Project, Leg removed, DNA extracted (1 m); New Mexico: Colfax County: Cimarron Canyon, Sangre de Cristo Mts., 7900’ [2408 m], 6 VII 1982, black light, E. & I. Munroe (1 m); same collection label / [CNC] slide No. 11733 male (1 m); same locality & collector, 8 VII 1962 (1 m); same locality & collector, 11 VII 1962 (1 m); Lincoln County: Capitan Mts., Capital Ridge, radio towers, summit, 10,000’ [3048 m], 3 VII 1982, RWH [Ronald H. Hodges] (2 m); same locality & collector, 10 VII 1982 / Genitalia slide # 17407 female (1 f); Otero County, High Rolls, Karr Cyn., 32.898° -105.813°, 2400 m, 9 VI 2016, L. G. Crabo leg. (1 f); Sandoval County: San Jose Ca[illegible]., 4 mi [6.4 km] E. Regina, Jemez Mts., NW slope, 8500’ [2591 m], 26 June, 1983, UV, RWH [Richard W. Holland] (1 m); Utah: [Iron County]: Cedar City, 11 mi [17.7 km] SE, 8300’ [2530 m], 29 VIII 1965, D. F. Hardwick (1 m); Sanpete County: Ephraim, 8 mi [12.9 km] E, 39.317°–[39.]337° -111.448°–[111.]470°, 10000’ [3048 m], 21 VII 2006, L. G. Crabo leg. / Specimen ID CNCLEP00140348/Barcode of Life Project, Leg removed, DNA extracted (1 m); same collection label / Specimen ID CNCLEP00140349 / Barcode of Life Project, Leg removed, DNA extracted (1m); Wyoming: Albany County: T13N R77W, Section 4, 1.5 mi (2.6 km) NW of Woods Landing, Fox Creek, el. 7,600 ft (2316 m), 21 VI 1997, black light trap, J. S. Nordin leg. (1 m): CNC, LGC, TM.

Figures 1–6. 

Rhabdorthodes adults 1 R. pattersoni, holotype male, USA, Colorado, Clear Creek County, Doolittle Ranch, Mt. Evans 2 R. pattersoni, paratype male, USA, Colorado, Teller County, Florissant, 5.6 km SW 3 R. pattersoni, paratype male, USA, Utah, Sanpete County, Ephraim, 12.9 km E 4 R. pattersoni, paratype female, USA, Colorado, Archuleta County, Pagosa Springs 5 R. durango, holotype male, Mexico, Durango, El Salto 6 R. petersoni, holotype male, Mexico, Nuevo Léon, Cerro Potosi.

Rhabdorthodes pattersoni is the most drab and poorly patterned of the three Rhabdorthodes species, appearing dull dark brown with faint markings. The forewing subterminal line of R. pattersoni is faint pale gray, whereas those of the Mexican species are more prominent, luteous preceded by dark wedge-shaped spots. Rhabdorthodes pattersoni is the only species in the genus that is known to occur in the United States.

Structurally, males of R. pattersoni are distinguished from the Mexican species by the smaller ventral process of the distal clasper (Figure 7), relatively short and triangular. In both other species this process is longer and curves toward the apex of the valve.

The shape of sternite A7 is shallowly concave with a quadrate lateral margin (Fig. 13). Those of the two Mexican species are more complex, with distinct lateral flanges, deeper pits, and more strongly concave edges (Figs 14, 15).

The Barcode Index Number (BIN) of R. pattersoni from Colorado and Utah (n = 5) is BOLD:ADH0770.

This moth resembles several nondescript brown species of Eriopygini – such as species of Homorthodes McDunnough and Protorthodes – but is probably most similar superficially to “Orthosia” noverca (Grote), a common widespread western North American moth that lacks a satisfactory generic placement. Most “O.” noverca have thicker and more prominent black forewing pattern elements than those of R. pattersoni. Rhabdorthodes can be identified without dissection by observing the ends of the valves for the chunky claspers in males and the sculpted seventh sternite in females. In addition, males of Rhabdorthodes have biserrate antennae, simple in look-alikes other than Protorthodes.

Figures 7–9. 

Rhabdorthodes male genitalia, valves and phalluses with everted vesicas 7 R. pattersoni 8 R. durango 9 R. petersoni.

Adults.Head. Male antenna total width 3 × shaft; dorsal scales dark gray-brown, scattered off-white on proximal ⅓. Labial palpus scales gray-brown, scattered off-white on second and third segments, increasing toward tip. Frons scales gray brown; dorsal head scales white tipped gray-brown.

Thorax. Dorsal scales long, white tipped gray-brown; appearing uniform dull gray-brown to dark brown. Wings: Forewing length 13.0–13.5 mm (males); 13.5 mm (females); scales gray-brown, scattered white tipped gray-brown, appearing uniform gray-brown to dark brown; costa spots luteous gray; basal, antemedial, and postmedial lines double, black and dark gray-brown, filling ground and slightly lighter gray; basal line uneven, indistinct; antemedial line slightly irregular, pointed basad on veins; medial line slightly darker than ground, angled distad from mid costa to reniform stigma, thence basad to posterior margin; postmedial line indistinct, evident mostly as black inner part and pale gray filling, scalloped; subterminal line irregular off-white patches between veins, preceding shade faint, brown; terminal line thin, dark gray; fringe striped dark gray, base thin, pale; orbicular stigma round, often incomplete, black, lined with few pale-gray scales, center ground color; claviform stigma small, black, filled with ground color, or reduced to a spot; reniform stigma moderate size, weakly figure-8 shaped, open at posterior end, black, with adjacent luteous and pale-gray lining strongest at medial and lateral sides, center ground color. Hindwing: Dorsum gray, basal ½ paler; veins and faint discal spot dark; terminal line thin, black; fringe gray with copper luster, base thin, pale.

Abdomen. Male genitalia: (Figure 7) Uncus length 0.9 × juxta. Juxta height 2 × width, rod length 1.2 × height. Valve length 5 × width, part distal to clasper curved slightly dorsad; cucullus weak, paddle shaped; sacculus length 0.5 × and width 0.75 × valve; distal clasper 1 × valve width, left slightly larger than right, thick, mesial surface with molar like ridges, dorsal distal margin expanded to broad rounded projection, ventral distal margin triangular with slight curve distad; ampulla directed 45° basad, scythe shaped with 120–180° curve distad; digitus small, thin. Phallus and vesica as in genus description. Female genitalia (Figs 10, 13): Sternite A7 lateral concavity shallow with quadrate raised lateral margin; posterior margin weakly concave. Papilla analis, segment A8, and bursa copulatrix as in genus description.

Figures 10–12. 

Rhabdorthodes female genitalia 10 R. pattersoni 11 R. durango 12 R. petersoni.

I am pleased to name this moth after Robert (Bob) Patterson of Bowie, Maryland in recognition of his contribution to the study and enjoyment of North American moths through his work on the Moth Photographers Group website (http://mothphotographersgroup.msstate.edu).

Rhabdorthodes pattersoni occurs in the mountains of the American West (Figure 16). It has been collected from southeastern Idaho and south-central Wyoming in the north to southwestern Utah, eastern Arizona and south-central New Mexico in the south. Most records are from Colorado and New Mexico. It flies in mid- to high-elevation forest at elevations from 1600 to 3050 meters. Collection dates range from early June to early August. The early stages are unknown.

This species is moderately common in collections. Specimens are often mixed in with other brown species in the tribe Eriopygini, often “Orthodes” noverca and “Orthodes” obscura (Smith).

Figures 13–15. 

Rhabdorthodes females. Distal abdomen (scales removed), left ventrolateral aspect showing sculpted sternite A7. 13 R. pattersoni 14 R. durango 15 R. petersoni.

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

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.

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.

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.

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.

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.

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.).

Mexico: Nuevo Léon: Cerro Potosi, 3139 m.

Holotype, male. Mexico: N.[uevo] L.[éon], Cerro Potosi, 10,300’ [3139 m], 15–16 VII 1963, H. & A. Howden. / Genitalia CNC slide No. 16495 / Specimen ID CNCLEP 00140417. CNC. Paratype. Female. Same data as holotype / Genitalia CNC slide 17438 female. CNC.

This moth is nearly identical to the other Mexican species, R. durango. Both Mexican species are more strongly patterned on the forewing than R. pattersoni, with stronger black markings and more vivid yellow filling of lines and stigmata. This yellow color is slightly more orange in R. petersoni than in R. durango. Definitive diagnosis requires examination of the genitalia, although the moths can most easily be identified by locality. Rhabdorthodes petersoni flies in the Sierra Madre Oriental and R. durango occurs in the Sierra Madre Occidental.

The base of the ampulla of the clasper of R. petersoni is oriented perpendicular to the dorsal valve, whereas those of the other two species are directed basad. The ventral process of the clasper is thinner and less strongly curved than in R. durango, and there is no significant dorsal process between the ampulla and ventral process. Together, the ampulla and ventral clasper process give the impression of an open lobster claw in R. petersoni.

The R. petersoni female is the only species in the genus that has a deep transverse sulcus across the ventrolateral part of sternite A7 (Figure 15).

Adults.Head. Male antenna width 4 × shaft; dorsal scales dark gray brown, scattered off-white on basal ⅓. Labial palpus proximal segments scales gray brown, scattered off-white; distal segment pale tipped gray brown. Frons gray brown; dorsal head scales hair like gray brown, pale tipped forked gray brown.

Thorax. Scales similar to head, slightly paler posteriorly; appearing uniform gray-brown, weak pale collar edge. Wings: Forewing length: 13.0 mm (male), 13.5 mm (female). Dorsum purplish dark gray-brown, costa black-brown, costa spots dark ochre; basal, antemedial, and postmedial lines double, black and dark gray, filling paler brown-gray; basal line scalloped, incomplete; antemedial line irregular, pointed basad on veins, perpendicular to wing; medial line faint, dark, evident costa to medial reniform stigma; postmedial line indistinct, scalloped, black inner component and pale filling most evident; subterminal line sinuous, pale ochre, strongest between veins, preceded by dark shade forming black wedges opposite cell and in fold; terminal line intervenal dark gray triangles; fringe ground color, base pale, thin; claviform stigma small, black, filling pale, brassy; orbicular stigma nearly round, moderately large (fused to claviform stigma in PT), black, filling slightly paler than line filling, central ocellus weak; reniform stigma moderately large, weakly kidney shaped, black, filling orange ochre peripherally, gray brown centrally. Hindwing: Dorsum dull medium fuscous, slightly paler on basal ½; veins and indistinct discal spot barely darker; terminal line thin, black; fringe gray, base luteous, edge light gray.

Male genitalia (Figure 9): Uncus length 1 × juxta height. Juxta height 3.3 × width, rod 1.2 × height. Valve length 6 × width, base widest in genus, segment distal to clasper thin, straight; cucullus, very weak, rounded; sacculus length 0.5 × and width 0.8 × valve; clasper thick, expanded distal part 1 × valve width, right larger than left, mesial surface spinulose, dorsum lacking process other than ampulla, ventral process long, curved slightly dorsad, claw shaped; ampulla base at dorsal valve ⅔ from base to apex, base broad, perpendicular to valve, curved 180° distad; digitus weak. Phallus and vesica as in genus description; vesica diverticulum slightly smaller than in the other species.

Female genitalia (Figs 12, 15): Posterolateral sternite A7 bisected by transverse sulcus, deepest laterally; posterior margin strongly concave, nearly semicircular. Papilla analis, segment A8, and bursa copulatrix as in genus description; ostium bursae leathery without median cleft.

I am pleased to name this moth for Merrill Peterson of Bellingham, Washington in recognition of his work on the Pacific Northwest Moths website (http://pnwmoths.biol.wwu.edu). This site is a well-illustrated interactive guide to the moths of the northwestern United States and British Columbia, Canada.

Rhabdorthodes petersoni is known only from the type locality at 3150 meters on Cerro Potosi, the highest peak in the Sierra Madre Oriental, Mexico (Figure 16). The habitat is unknown, although it is most likely forest. Both known specimens were collected in mid-July. The early stages are unknown.

This species was found by J. Donald Lafontaine amongst unsorted Mexican material at the CNC. Although this moth is only known from Mexico it could conceivably occur in western Texas, particularly in the Davis and Chisos mountains. These ranges are the northernmost extension of the Sierra Madre Oriental.

Figure 16. 

Distribution of examined material of Rhabdorthodes in North America. R. pattersoni (yellow), R. durango (red), R. petersoni (blue).