Rhabdorthodes petersoni, 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 : 193-195

Rhabdorthodes petersoni sp. n. Figs 6, 9, 12, 15, 16

Type locality.

Mexico: Nuevo Léon: Cerro Potosi, 3139 m.

Type material.

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.

Diagnosis.

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).

Description.

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.

Etymology.

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.

Distribution and ecology.

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.

Remarks.

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.