Lasionycta silacea Crabo & Lafontaine

Crabo, Lars & Lafontaine, Donald, 2009, A Revision of Lasionycta Aurivillius (Lepidoptera: Noctuidae) for North America and notes on Eurasian species, with descriptions of 17 new species, 6 new subspecies, a new genus, and two new species of Tricholita Grote, ZooKeys 30 (30), pp. 1-156: 89-91

publication ID 10.3897/zookeys.30.308

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scientific name

Lasionycta silacea Crabo & Lafontaine

sp. n.

Lasionycta silacea Crabo & Lafontaine   , sp. n.

Figs 95–98, 181, 236. Map 19

Type material. Holotype ♁. Canada, British Columbia, Blowdown Pass near Gott Peak , [50° 21' N 122° 08' W], 7100’, 5–6 Aug. 1993, J. Troubridge. CNC GoogleMaps   . Paratypes 202 ♁, 78 ♀. Canada. British Columbia. Same data as holotype (3 ♁, 2 ♀) GoogleMaps   ; same locality as holotype, 5–6 Aug. 1993, L. Crabo and J. Troubridge (2 ♁, 1 ♀), 20 Aug. 1993, L. and A. Crabo and J. Troubridge (5 ♁, 3 ♀), 30 July 1994, L. Crabo and J. Troubridge (28 ♁, 3 ♀), 23 Aug. 1996, J. Troubridge (9 ♁, 2 ♀), 17 Aug. 2000, J. Troubridge (1 ♁), 6 Aug. 2005, L. G. Crabo (19 ♁, 7 ♀), 26 July 2006, L. G. Crabo (14 ♁, 1 ♀) GoogleMaps   ; Gott Peak near Duffy Lake , 30 July 1994, J. Troubridge (35 ♁, 9 ♀)   ; Mt. McLean , 6–7000’, 16 July 1994, J. Troubridge (4 ♁, 4 ♀)   ; Mission Ridge , 5800’, 50° 45' N 119° 37' W, 15–16 July 1994, L. Crabo and J. Troubridge (7 ♁, 2 ♀), 10 July 1998, J. Troubridge (6 ♁, 1 ♀) GoogleMaps   ; Coast Range, Perkins Peak , 51.82-[51.8] 3° N 125.02- [125.0] 3° W, 6230–7400’, 5 Aug. 2005, L. G. Crabo (1 ♁, 1 ♀) GoogleMaps   ; USA. Washington. Chelan County, Junior Point , 47° 59' N 120° 23' W, 6100’, 4 Aug. 1989, L. Crabo and C. Coughlin (1 ♁, 1 ♀), 27 Aug. 1998, J. Troubridge (10 ♁, 10 ♀) GoogleMaps   ; Kittitas County, Quartz Mtn. , [47.074° N 121.081° W] 6400’, 14 July 1990, L. G. and A. G. Crabo (2 ♀), 15 July 1996, J. Troubridge (4 ♁), 28 July 2003, L. G. and E. K. Crabo (1 ♁), 14 July 2005, C. Coughlin and L. Crabo (5 ♁, 6 ♀), 16 July 2007, L. G. Crabo (1 ♁, 3 ♀), 25 July 2009, L. G. and E. K. Crabo (1 ♁, 1 ♀) GoogleMaps   ; Okanogan-Whatcom County line, Slate Peak , 48.73-[48]. 74° N 120.66-[120]. 70° W, 7320’, 7 Aug. 1988, L. G. Crabo (2 ♀), 8 Aug. 1988, L. G Crabo (2 ♀), 13 Aug. 1993, J. and L. Troubridge (21 ♁, 4 ♀), 13 July 2005, L. G. Crabo (9 ♁) GoogleMaps   ; Yakima County, Bethel Ridge , [46.79° N 121.09° W], 6500’, 29 July 1989, L. G. Crabo and J. P. Pelham (5 ♁, 1 ♀), 18 July 1997, L. G. Crabo (1 ♁, 2 ♀), 4, 25 July 1996, 18 July 1997, and 22 Aug. 1997, J. Troubridge (7 ♁, 7 ♀), 27 July 2003, L. G. and E. K. Crabo (2 ♁, 1 ♀). AMNH, CDFC, CNC, GBC, JSC, LGC, OSU, TMC, UASM, USNM, WSU GoogleMaps   .

Etymology. Silacea is derived from the Latin silaceus meaning like yellow ocher. It refers to the yellow color on the forewing of the moth.

Diagnosis. Lasionycta silacea   has an olive-brown forewing with ochre patches and filling of lines and spots. It is found in the Pacific Northwest. Vivid specimens are unmistakable due to the olive and yellow color. Drab specimens are similar to L. promulsa  

with which it occurs in British Columbia, but can be recognized by the faint ocellus in the orbicular spot and yellower underside with a larger hindwing discal spot. The orbicular spot of L. promulsa   lacks an ocellus, its underside is gray brown, without a yellow cast, and the ventral hindwing discal spot is small and indistinct. Th e male and female genitalia of L. silacea   are similar to those of L. promulsa   but the appendix bursae is more pointed posteriorly.

Lasionycta silacea   has the most divergent CO1 sequences in the L. promulsa   subgroup, differing from other species by over 1.3 %. Th e two haplotypes differ by 0.16 %.

Description. Head – Antenna of male strongly biserrate and fasciculate, 2.2– 2.6× as wide as central shaft, individual segments triangular with slightly concave distal side and acute apices. Antenna of female filiform and ciliate. Dorsal antenna segments dark olive gray proximally, slightly lighter olive gray distally. Scape light grayish yellow, tuft at base of dorsal antenna light gray. Eye normal size. Palpus light grayish yellow medially, similar scales mixed with gray scales laterally. Frons light grayish yellow centrally, light gray laterally. Top of head a mixture of entirely pale yellowish-gray hair-like scales and similar scales banded subapically with dark gray and tipped with white, appearing light olive gray. Thorax – Vestiture uniform, same as top of head. Legs with femora covered with olive-gray and yellow scales, tibiae with slate-gray and pale-luteous scales, tarsal segments mostly slate gray ringed distally with pale luteous. Wings – Forewing length: males 14–17 mm (expanse 32–37 mm); females 16–18 mm (expanse 36–38 mm). Forewing ground color a mixture of medium to dark olive-gray, ochre and tan to orange scales, appearing slightly mottled medium to dark olive gray with patches of light to medium grayish ochre. Basal, antemedial, and postmedial lines slightly darker olive gray, ill defined, weakly double with grayish-ochre filling. Basal and antemedial lines irregular. Medial line complete but faint. Postmedial line moderately scalloped between veins, evenly excurved from costa to lower cell then nearly straight to end perpendicular to posterior margin. Subterminal line gray ochre, slightly irregular, preceded by a uniform slightly darker gray-olive shade. Terminal line thin, gray olive. Spots similar color to lines. Orbicular spot round to oval, filled with ground color or slightly lighter scales and an ocellus of same color as spots and lines. Reniform spot kidney shaped, faint, filled with light gray ochre peripherally and same color as lines centrally. Claviform spot absent. Fringe darker gray basally and lighter gray ochre distally, faintly checkered with gray olive between veins. Ventral forewing light olive gray centrally and distal to expected position of the subterminal line, lighter gray ochre in anterior cell, distal to discal spot, and in subterminal area anterior to cubital vein. Discal spot slightly darker, bar like, evident due to lighter scales adjacent to anterior half of spot. Postmedial line similar gray to forewing margin, ill defined, darkest and widest near costa, faint elsewhere. Terminal line thin, evident between veins. Fringe gray ochre, checkered with olive gray between veins. Dorsal hindwing ground color pale gray yellow dusted with dark-gray scales, lighter at costa. Discal spot barely evident, chevron shaped. Postmedial line gray, ill defined, irregular and slightly scalloped in a few specimens. Marginal band fuscous gray, wide with indistinct inner margin, extending proximal- ly almost to postmedial line. Fringe light to medium ochre. Ventral hindwing pale grayish ochre to light gray brown, darker at costa, with dusting of light- to mediumgray scales. Veins slight darker gray, especially distal to postmedial line. Discal spot an ill defined triangle, darker gray than other hindwing markings. Postmedial line light gray, usually inconspicuous and incomplete but occasionally prominent and complete. Marginal band light to medium gray, with ill-defined inner margin. Fringe light to medium ochre. Abdomen – Covered with uniform yellow-gray scales. Male genitalia – (Fig. 181) Genital capsule and aedeagus as in L. leucocycla   species-group and L. promulsa   sub-group descriptions. Valve approximately 6–7× as long as wide, with costal lobe of sacculus extending above costal valve margin and moderate neck at base of cucullus. Corona single, partially double at apex. Digitus oriented 30° ventral to valve. Vesica with 1–2 (N = 5) slightly angled spike-like basal cornuti placed adjacent to each other on vesica coil. Female genitalia – (Fig. 236) Ovipositor lobe, segment VIII, and bursa copulatrix generally as in L. leucocycla   species-group and L. promulsa   sub-group descriptions. Th e corpus bursae relatively large. The distal appendix bursae is relatively slender and pointed.

Distribution and biology. Lasionycta silacea   occurs from the British Columbia Coast Range and Washington Cascades to extreme southwestern Alberta. It is common near treeline. Adults are nocturnal and fly from early July through August.


Canadian National Collection of Insects, Arachnids, and Nematodes


American Museum of Natural History


Oklahoma State University, Collection of Vertebrates


Trudeau Mycobacterial Culture Collection, Trudeau Institute


University of Alberta, E.H. Strickland Entomological Museum


Smithsonian Institution, National Museum of Natural History


Weber State University, Bird and Mammal Collection