Sympistis chons Troubridge

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: 32-33

publication ID 10.11646/zootaxa.1903.1.1


persistent identifier

treatment provided by


scientific name

Sympistis chons Troubridge

sp. n.

Sympistis chons Troubridge   sp. n.

(Figs. D-18, D-19, D-20, M-7, R-4)

Diagnosis. Sympistis chons   can be distinguished from S. amun   by the characters given above, except in the Peace River Valley, British Columbia and Alberta, where S. chons   is very dark and looks much like S. amun   . DNA analysis puts these northern specimens with S. chons   . This species becomes paler towards the south, where the forewing is light gray and the hindwing marginal band almost absent in some Arizona specimens. On the Great Plains, S. chons   occurs in badlands and dry river valleys and S. riparia   occurs on dunes. The subterminal line of S. riparia   is present as an undulating pale line or series of pale dots (Figs. E-2, E-3); that of S. chons   is more deeply jagged, particularly in the anal angle. In the south, S. chons   could be confused with S. deserticola   or S. major   . The orbicular and particularly the claviform spots of S. deserticola   (Fig. D-12) and S. major   (Figs. D-13, D-14) are highlighted with white scales; these spots are less contrasting and light gray rather than white in S. chons   .

Description. Antennae filiform, prothoracic collar hoary charcoal gray with wide, light gray median band diffuse charcoal median line within the median band; head and thorax a mix of black and light gray scales gives a hoary dark gray appearance; abdomen light grayish brown. Coremata with brushes, levers, and pockets present on base of male abdomen. Forewing length 15-17 mm. Dorsal forewing light gray and black scales give forewing powdery gray appearance; antemedial and postmedial lines usually obscure, absent, or present as black dots on veins; orbicular spot ellipsoidal; orbicular, reniform, and claviform spots dark gray, bordered with light gray or scattered white scales on the inner row and thin black outer row of scales; thin black basal dash extends into claviform spot; black lines extent through each cell in subterminal portion of wing, meeting black terminal line which is present as a series of small chevrons between veins; slightly obscure, white subterminal line deeply denticulate; fringe dark gray, lightly checkered with light gray at tips of veins. Dorsal hindwing very light grayish basal area blends to dark grayish brown terminal shade in male, slightly darker in female; veins and discal lunule highlighted with scattered grayish brown scales; fringe white with narrow gray median line. Male genitalia. (Fig. M-7) Valve shaped like the prow of a canoe with distinct corona; ampulla of clasper squat, bends posteriorly with terminal spine arcing upward from posterior margin. Vesica with two small basal diverticulae, bends slightly downward about ½ of the way from base; a ribbon of sparse cornuti extends dorsally from base of vesica to apex; a second ribbon of longer, stouter cornuti extends dorsolaterally on right of apical ½ of vesica; a single spine and a tuft of longer cornuti extend from apex. Female genitalia. (Fig. R-4) Ovipositor lobes rounded, apex with ring of long setae, corona of short setae mid way down -these setae produced at 90° to the abdomen; a ruff of longer, finer setae encircles ovipositor lobes at base; a small sclerite occurs on ventral surface of ductus bursae at ostium bursae, ductus bursae elongate, widening slightly in middle ½ and then narrowing at appendix bursae; appendix bursae elongate gradually narrows toward ductus bursae, rounded at anterior end with ductus seminalis arising from ventral side of anterior end; corpus bursae about ½ as large as appendix bursae arises from left side of appendix bursae near ductus bursae, elongate signae on dorsal and ventral sides.

Type material. Holotype male: Canada, British Columbia, Kirby Flats Rd. , 50° 32' N, 121° 43' W, 7 vii 2000, J. Troubridge, in the CNC GoogleMaps   . Paratypes: 99♂ 43♀: British Columbia: same data as holotype GoogleMaps   , 3♂ 2♀; E. end of Seton Lk., base of Mt. McLean , 21 vi 1996, J. Troubridge   , 17♂ 8♀; E. end of Seton Lk., base of Mt. McLean , 5 vii 1996, J. Troubridge   , 1♂; Hwy 99 at BC Hydro dam at Seton Lk. , 3 vi 1995, J. Troubridge   , 12♂ 4♀; Hwy 99 at BC Hydro dam at Seton Lk. , 23 vi 1995, J. Troubridge   , 1♂ 10♀; E. end of Seton Lk. , 13 vi 1996, J. Troubridge   , 12♂ 2♀; Kirby Flats Rd. , 50° 32' N, 121° 43' W, 10 vii 1999, J. Troubridge GoogleMaps   , 3♂ 2♀; Kirby Flats Rd. , 50° 32' N, 121° 43' W, 12 vii 1998, J. Troubridge GoogleMaps   , 3♂ 1♀; Kirby Flats Rd., S. of Lillooet , 29 viii 1997, J. Troubridge   , 3♂ 1♀; Kirby Flats Rd., S. of Lillooet , 6 vii 1999, J. Troubridge   , 1♂; Kirby Flats Rd., S. of Lillooet , 18 vii 2000, J. Troubridge   , 2♂ 1♀; Kirby Flats Rd., S. of Lillooet , 4 vii 1997, J. Troubridge   , 1♀; Kirby Flats Rd., S. of Lillooet , 21 vi 2001, J. Troubridge   , 1♂; Kirby Flats Rd., S. of Lillooet , 2 vii 1998, J. Troubridge   , 1♂; Peace River , 56° 07' N, 120° 03’ W, 11 vii 1999, J. Troubridge GoogleMaps   , 6♂ 1♀; White Lk. , NW of Oliver, 30 vi 1996, J. Troubridge   , 1♂. Alberta: Writing on Stone , 49° 05' N, 111° 37' W, 28 vi 2000, J. Troubridge GoogleMaps   , 15♂ 3♀; Lost River, Onefour , 49° 01' N, 110° 26' W, 26-27 vi 2000, J. Troubridge GoogleMaps   , 7♂ 1♀; Waterton Lks NP, Blakiston Valley Rd., Bellevue Hill , 39.100° N, 113.903° W, 7 vii 2005, B. C. Schmidt GoogleMaps   , 3♂ 2♀; Whistler Mtn. , 49.333°N, 114.331° W, 4800’, 11 viii 2004, B. C. Schmidt GoogleMaps   , 1♀ 15 km E. Trochu, Tolman Bridge , (east), 1 vii 2001, B. C. Schmidt and G. Anweiler   , 2♂; Dunvegan, Hwy 2 at Peace River , 7 vii 2002, B. C. Schmidt   , 1♂. Oregon: Baker Co., Brownlee , 44° 50' N, 116° 53' W, 12 vi 1999, J. Troubridge GoogleMaps   , 1♀. Nevada: Elko Co., Angel Lk. , 41° 01' N, 115° 04' W, 2550m., 23 vii 2001, Lafontaine and Troubridge GoogleMaps   , 3♂. Utah: San Juan Co., Ranger’s Residence , Canyonlands NP., 4 vi 1994, P. Opler   , 1♂.

Etymology. From Egyptian mythology, Chons is the moon-god. It is a noun in apposition.

Distribution. This species occurs from the Peace River in northern British Columbia, south to Arizona. The species occurs in xeric habitats, including prairie badlands and river valleys, ponderosa pine forests, and deserts.


Canadian National Collection of Insects, Arachnids, and Nematodes