Protogygia pryorensis, Crabo & Kirst, 2023

Crabo, Lars G. & Kirst, Marian L., 2023, Protogygia pryorensis Crabo & Kirst (Insecta, Lepidoptera, Noctuidae, Noctuinae, Noctuini), a new moth species from Montana, United States of America, ZooKeys 1175, pp. 311-319 : 311

Protogygia pryorensis sp. nov.

Figs 1 , 2

Type locality.

USA: Montana: Carbon County: Pryor Mountains, Petroglyph Canyon Natural Area, 45.0167, -108.5022, 1520 m.

Type material.

Holotype, male. USA: Montana: Carbon County: 45.01671°N, 108.502244°W, Petroglyph C[an]y[o]n Natural Area, high desert sand dunes. Juniper, sage, pine, currant, skunk sumac. 6 May 2022, 4990' [1520 m], uv/mv trap, leg: M. L. Kirst/I. Sommerdorf. / [Crabo genitalia slide] 665 male. CNC. Paratypes. 15 m, 0 f. USA: Montana: Same collection data as holotype (5 m); [same locality as holotype] Petroglyph C[an]y[o]n B[ureau of] L[and] M[anagement], 45.016, -108.502, 8-9 May, 2023, 1470 m, L. Crabo, M. Kirst, C. Harp (10 m). CNC, CSUC, JVC, LGC, MKC, NMNH.

Diagnosis.

Protogygia pryorensis is a superficially distinctive moth (Fig. 1 ). It is the only Protogygia species with a combination of cream-filled oval orbicular and crescentic reniform spots, sharply dentate postmedial line, and gray hindwing with white fringe. Although not as streaked as many Protogygia species, the combination of light veins and strongly toothed postmedial line produces a somewhat streaky pattern on the distal forewing. Protogygia elevata (Smith) and Protogygia arena Troubridge & Lafontaine are the most similar Protogygia species to P. pryorensis in color and pattern. Both typically have darker central areas in the forewing spots, a more typical noctuid forewing pattern with lightly scalloped lines, and lighter hindwings. Neither of these two species is known to occur in Montana, but P. elevata has been found as far north as southwestern Wyoming suggesting that the distributions of it and P. pryorensis could potentially overlap.

Protogygia pryorensis is the only brownish Protogygia with a forewing pattern of complete transverse lines and distinct spots that has male genitalia with a cylindrical uncus ending in a hook and a teardrop-shaped clasper (Fig. 2a ). The unci of P. elevata and P. arena are blunt tipped and swollen basally, and their claspers are apically blunted. This is discussed further in regards to species groups in the last paragraph of this section. Both of these superficially-similar species have simple hairlike scales on the dorsal thorax, which are wider and either forked and spatulate in P. pryorensis .

Protogygia milleri (Grote) is structurally similar to P. pryorensis and has an unstreaked forewing with somewhat similar pattern elements ( Lafontaine 2004, pl. I figs 41, 42). They key out together in couplet 12 of the "Key to Species of Protogygia " in Lafontaine and Fauske (2004, pp. 183, 184). Nonetheless, P. milleri cannot be mistaken for P. pryorensis because it only occurs in California and Oregon and its forewing is powdery gray rather than olive gray as in P. pryorensis , with simple black lines and spot outlines.

The female of P. pryorensis is unknown but is likely to resemble the male based on the females of other species in the genus.

Lafontaine and Fauske (2004) organize Protogygia into three species groups. The wing pattern of P. pryorensis , with unfused orbicular and reniform spots and distinct transverse lines, resembles the three species of the Protogygia elevata -group (ibid., pl. I figs 24-28). However, P. pryorensis lacks the defining structural characters of this group: basal swelling and truncate apex of the uncus and truncate ampulla of the clasper (ibid., pl. 27 figs 1, 2). We assign P. pryorensis to the album -group based on its cylindrical apically hooked uncus and teardrop-shaped clasper, both typical of the other six species in this group (ibid., pl. 27 figs 3-8). All other species in the album -group except P. milleri are either nearly white or streaked longitudinally (ibid., pl. I figs 29-42).

Description.

Adult male. Head - Antenna biserrate and bifasciculate, width 2 × central shaft; dorsal scales yellow gray; scape white. Labial palpus scales cream and scattered gray, additional long dark gray hairlike scales on sides; haustellum well developed. Frons bulging; scales of frons and vertex hairlike, long, cream, with scattered medium gray scales near eyes and between antennae. Eye normal size, hairless, with long dark posterior lashes. Thorax - Dorsal vestiture long, narrow, forked, or weakly spatulate serrate, cream, ochre, and black scales, appearing hoary light gray with faint dark pattern, a diffuse darker gray line across prothoracic collar and dark tufts in some specimens; tegula with diffuse black V and gray-tan or tan medial margin; short loose dorsal tufts on meso- and metathorax. Legs: Prothoracic tibia with ~ 5 spinelike setae along sides, apical pair slightly longer and ~ 2 × as stout as the others; mesothoracic and metathoracic tarsi with three rows of setae. Wings: Forewing length 12.5-15.0 mm (N =16); distal wing elongated to bluntly pointed apex with smooth convex outer margin; scales straplike, serrate, mixed orange tan, cream, and black; wing base proximal to antemedial line, postmedial area, and veins olivaceous pale gray; veins bordered by thin black lines in medial and terminal areas; medial and subterminal areas medium dark olive gray, posterior half of medial area frosted with light gray; transverse lines dark gray, single, diffuse except as noted; basal and medial lines absent; antemedial line indistinct, convex laterally thrice, strongest on mid-wing, distal side variably shaded dark gray to black; postmedial line strongly dentate, diffuse except for long thin teeth on veins, proximal shade similar to distal shade of antemedial line; subterminal line jagged, diffuse dark brown with intervenal smudgy dark wedges; terminal line thin, black; fringe mostly cream with light tan base and thin medial line; spot outlines thin, black; claviform spot complete or incomplete, thicker than other spots, filled with adjacent ground; orbicular spot ovoid, size variable, filling light cream; reniform spot strongly kidney-shaped to crescentic, filling darker cream, rarely with light gray center. Hindwing medium gray with slightly darker veins, diffuse discal spot, and diffuse postmedial line; fringe white with cream base and thin light gray medial line. Abdomen - Lacking structural modifications such as hair pencils or pockets; vestiture uniform grayish cream. Male genitalia: (Fig. 2 ) Uncus cylindrical, width nearly uniform, tapering to slight apical downward hook. Juxta shield shaped, height 1 × width. Clavus knoblike with apical short setae. Valve straplike, length ~ 4 × width, widest at mid-sacculus due to broad ventral bulge, ventral process absent, tapering slightly distally to unmodified blunt apex bearing small corona of loose clawlike setae; sacculus length ½ × valve length, nearly reaching dorsal valve near base; clasper ampulla on mid-valve, teardrop shaped with broad base tapering to acute apex. Phallus tubular, length 4 × width; vesica base bent 90° rightward, then coiled 360°, widest near apex; relatively short fingerlike subbasal diverticulum with apical short acute cornutus. Female genitalia: Unknown.

Etymology.

The species epithet pays homage to the ecologically rich Pryor Mountains in south-central Montana, where MLK as a child spent many happy hours exploring. The Pryor Mountains are named for Nathaniel Hale Pryor, a Sergeant with the Lewis and Clark Expedition that traveled through Montana in 1805.

Distribution and ecology.

The only known locality for P. pryorensis near the north mouth of Petroglyph Canyon is located in the Petroglyph Canyon Natural Area, a 97-ha system of high-desert bluffs and drainages in the southern foothills of Big Pryor Mountain in southern Carbon County, Montana. This area is in the most northern portion of the Wyoming Basin Ecoregion, a region centered in western Wyoming that barely extends into southern Montana ( United States Environmental Protection Agency 2000). The Pryor Mountains are unglaciated, unique for a Montana range, and are instead the erosional product of uplifted and tilted sedimentary blocks: a western block (Big Pryor Mountain) and an eastern block (East Pryor Mountain). The range rises abruptly from the surrounding prairie to an elevation of more than 2400 m, resulting in essentially a sky island that is unique within Montana ( Anonymous 2023). These mountains are notable for their unique geology, animal diversity, and globally rare plant communities that include regionally-endemic plant species such as Shoshonea [ Shoshonea pulvinata , Evert & Constance ( Apiaceae )] and thick-leaf bladderpod [ Physaria pachyphylla O’Kane & Grady ( Brassicaceae )] ( Lyman et al. 2015). The foothills southwest of Big Pryor Mountain contains Montana’s only true red desert and receive less than 13 cm of annual rainfall due to the double rain shadow of the Beartooth Mountains to the west and the Pryor Mountains to the north ( Anonymous 2023). Petroglyph Canyon runs northwest to southeast for 1.5 km. ( Anonymous 2015). Its northern trailhead is at a contact between the Kootenai (Cretaceous), Fall River, and Thermopolis Formations. These formations are characterized by sedimentary deposits of varying hardness, including thick shale beds, bentonitic mudstones, fine-grained and course-grained sandstones, and conglomerates ( Lopez 2000).

The P. pryorensis type locality (Figs 3 , 4 ) lies fully within the Kootenai (Cretaceous) formation. It is a relatively small patch of active sands and coppice dunes surrounding spirelike hoodoos composed of cross-bedded fluvial sandstone (M. Smith pers. comm. January, 2023). It is sparsely vegetated with trees, shrubs, and herbaceous plants. The predominant trees are limber pine [ Pinus flexilis James ( Pinaceae )] and Utah juniper [ Juniperus osteosperma (Torr.) Little ( Cupressaceae )], with shrubs consisting primarily of big sage [ Artemisia tridentata Nutt. ( Asteraceae )], green rabbitbrush [ Chrysothamnos viscidiflorus Hook. (Nutt.) ( Asteraceae )], currant [ Ribes spp. ( Grossulariaceae )], and skunkbush sumac [ Rhus trilobata Nutt. ( Anacardiaceae )]. Dominant forbs include phlox [ Phlox spp. ( Polemoniaceae )], Cryptantha spp. ( Boraginaceae ), desert dandelion [ Malacothrix spp. ( Asteraceae )], and Streptanthella longirostrus S. Watson, Rydb. ( Brassicaceae ) ( Lesica et al. 2012). Extensive low mats of prickly pear cactus [ Opuntia polyacantha Haw. ( Cactaceae )] are present on the sand and fine-grained soils.

All P. pryorensis were collected within a 200 m radius (approximately 3.2 ha) centered on 45.016, -108.502, where most of the traps were placed. This area includes areas of confluent sand as well as areas of mixed sand, bedrock, and fine-grained soil. The sand habitat with which P. pryorensis appears to be most closely associated extends farther to the north as well as into the canyon, but these areas were sampled only with one trap placed on the canyon floor on May 8, 2023 and one placed between the canyon floor and upper sand habitat on May 19, so the local distribution of this species is probably underestimated. All specimens were collected in traps and none at sheets, suggesting either that the flight is after midnight or that P. pryorensis is not attracted to bright mercury vapor light. All specimens were found from May 6 to May 9, with none collected May 19 or June 1, indicating a brief flight period. All six specimens from May 6, 2022 are fresh, while a few of the specimens from May 8 and 9, 2023 demonstrate slight wear. No females have been found.

The early stages of P. pryorensis are unknown. It is possible that the larvae burrow in sand, a habit of known larvae from the closely-related genus Copablepharon Harvey ( Lafontaine and Fauske 2004).

Figures

Figure 1. Protogygia pryorensis, paratype male, USA, Montana, Carbon County, Pryor Mountains, Petroglyph Canyon Natural Area.

Figure 2. Protogygia pryorensis, male genitalia a valves b phallus with everted vesica.

Figures 3, 4. Protogygia pryorensis habitat at Petroglyph Canyon Natural Area, Carbon County, Montana, USA 3 shows active sands and sandstone hoodoos at a canyon entry, while 4 is a nearby area of mixed soils and interspersed bedrock above the canyon rim. Sparse woody vegetation of Juniperus osteosperma, Pinus flexilis, Chrysothamnos viscidiflorus and Artemisia tridentata and mats of Opuntia polyacantha are depicted.