Sympistis acheron Troubridge, 2008

Troubridge, J. T., 2008, A generic realignment of the Oncocnemidini sensu Hodges (1983) (Lepidoptera: Noctuidae: Oncocnemidinae), with description of a new genus and 50 new species, Zootaxa 1903 (1), pp. 1-95 : 23-24

Sympistis acheron Troubridge sp. n.

(Figs. D-4, L-8, Q-4)

Diagnosis. Externally, S. glennyi , S. cocytus and S. acheron are very similar and difficult to separate. Significant geographic variation is found in each of these species; however, in general, the hindwing marginal band is more sharply defined in S. glennyi (Figs. B-17, B-18) and the forewing tends to be less hoary than in the other two species. The basal portion of the hindwing of S. acheron tends to be darker than that of S. cocytus or S. glennyi . The ampulla of the clasper of S. glennyi is long, tapers evenly to a point (Fig. L-7), and can usually be seen by brushing specimens. Those of S. acheron and S. cocytus are talon like (Figs. L-8, L-9). In S. cocytus , the distal margin of the ampulla curves evenly to the tip of the terminal spine (Fig. L-9), whereas the distal margin curves toward the base of the terminal spine in that of S. acheron (Fig. L-8). The vesica of S. cocytus bends gently downward (Fig. L-9) but that of S. acheron bends abruptly at almost 90° to the right (Fig. L-8). The appendix bursae of S. cocytus gradually narrows toward the ductus bursae with a small bulge on the right side (Fig. Q-5), but that of S. acheron is sausage shaped with the ductus bursae arising a little to the left of the right end of the sausage (Fig. Q-4).

Description. Holotype. Antennae filiform. Prothoracic collar beige with black basal and dark brown terminal lines. Head brown, thorax shades of gray, dark brown, and beige scales. Coremata with brushes, levers, and pockets present on base of male abdomen. Forewing length 16-19 mm. Dorsal forewing ground color grayish brown; ordinary lines and spots crisp and clear; black antemedial line edged basally with pale beige scales; black postmedial line edged distally with pale beige scales; basal line black; median line dark grayish brown; black terminal line a series of chevrons edged basally with scattered light beige scales; subterminal line a row of grayish brown chevrons, bordered distally with scattered light beige scales; orbicular, claviform and reniform spots distinctly bordered with black scales, filled with beige and light rust scales –reniform spot filled with grayish brown in lower half; fringe a series of dark cream, dark brown, then brown lines, checkered with darker shades between veins. Dorsal hindwing basal half heavily suffused with grayish brown, gradually blending to dark grayish brown marginal band; discal lunule dark grayish brown; fringe cream basally, a dark gray median line, cream distally. Male genitalia. (Fig. L-8) Valve with pointed, upturned apex; distal margin of ampulla of clasper curves toward base of terminal spine. Vesica bends abruptly at almost 90° to the right; a ribbon of sparse cornuti runs along dorsal and posterior sides to meet a dense ribbon of cornuti on ventral apical ½ of vesica and a dorsal patch of dense cornuti on apical ½ of vesica; a single, coarse apical cornutus and small bundle of cornuti projected from apex. Female genitalia. (Fig. Q-4) Ovipositor lobes rounded with scattered setae; a corona of short setae surrounds ovipositor lobes near tip, these setae produced at 90° to the abdomen; a ruff of longer, finer setae encircles ovipositor lobes at base; a sclerite occurs on ventral surface of ductus bursae at ostium bursae, ductus bursae narrow; sausage-like appendix bursae extends with ductus seminalis at anterior end and ductus bursae arising a short distance before posterior end; corpus bursae absent.

Type material. Holotype female: USA: Oregon, Jackson Co., Mt. Ashland , 42° 04' N, 122° 42' W, 6400', 2 viii 1998, J. Troubridge, in the CNC . Paratypes: 22♂ 2♀: British Columbia: Kirby Flats Rd. , 50° 32' N, 121° 43' W, 2000-3500’, 20 viii 1998, J. Troubridge , 1♀. Washington: Bethel Ridge , 46° 42' N, 121° 07' W, 5800', 27 viii 1998, J. Troubridge , 1♂; Bethel Ridge , Yakima Co., 19 viii 1995, J. Troubridge , 1♂; Junior Pt., Chelan Co., 47° 59' N, 120° 23' W, 6100', 5 viii 1999, J. Troubridge , 3♂; Junior Pt., Chelan Co., 6800', 9 viii 1997, J. Troubridge , 2♂. Oregon: Baker Co., Burnt R. Cyn. , 44° 34' N, 117° 34' W, 3031’, 19 ix 2001, J. Troubridge , 2♂; Lane Co., Frissel Pt., 1506 Rd. , 25 vii 1996, J. Troubridge , 1♂. California: Tioga Pass , 8500- 10000’, 31 vii-1 viii 1995, Troubridge and Crabo , 1♂; Happy Valley , Plumas Co., 39° 52' N, 120° 27' W, 5600’, 29 viii 2000, J. Troubridge , 1♂; Mt Shasta , 41° 21' N, 122° 12' W, 7600’, 27 viii 2000, J. Troubridge , 7♂ 1♀; Mt Shasta , 41° 21' N, 122° 12' W, 7600’, 15 ix 1998, J. Troubridge , 3♂.

Etymology. There are five rivers that separate Hades from the world of the living. The river Acheron is the river of woe. Separating S. acheron from S. glennyi and S. cocytus will be a woeful experience for taxonomists. It is a noun in apposition.

Distribution. This species occurs at or near treeline from south central British Columbia to the central Sierra Nevada, California.