Scolytus piceae (Swaine, 1910)

Smith, Sarah M. & Cognato, Anthony I., 2014, A taxonomic monograph of Nearctic Scolytus Geoffroy (Coleoptera, Curculionidae, Scolytinae), ZooKeys 450, pp. 1-182 : 41

Taxon classification Animalia Coleoptera Curculionidae

Scolytus piceae (Swaine, 1910) Figs 29, 43

Eccoptogaster piceae Swaine, 1910: 34.

Scolytus piceae (Swaine, 1910): Blatchley and Leng 1916: 589.

Diagnosis.

Both sexes are easily diagnosed by the large conical median spine on the surface of the second ventrite, the spine base never touches any margin, by the lack of lateral denticles on the apical margins of ventrites 2-4 and by the unicolorous elytra.

Description (male).

2.5-3.0 mm long (mean = 2.4 mm; n = 12); 2.3-2.7 times as long as wide. Color red-brown to dark red brown, antennae yellow-brown, legs dark red-brown to yellow brown apically. Pronotum typically darker than elytra.

Head. Epistoma weakly emarginate; epistomal process present, moderately developed, low; median area above mandibles bearing dense patch of long, yellow, hair-like setae. Frons appearing flattened when viewed laterally from epistoma to vertex, slightly transversely impressed just above epistoma to inner apices of eyes; moderately, coarsely longitudinally aciculate-punctate; aciculations converging at epistoma; punctures large, dense, coarse; moderately, uniformly covered by long, fine, yellow, erect, hair-like setae, these longer than width of midpoint of eye. Antennal scape short, elongate; club flattened, irregularly ovoid, setose with partial septum, two arcuate sutures visible.

Pronotum wider than long; apical margin broadly rounded, median area between eyes lined with scales; sides distinctly arcuate, strongly constricted near apex, forming a weak transverse impression near apical margin; surface smooth, shining, punctures on disc fine, shallow, moderately abundant, larger and more abundant laterally and on apical constriction; apical and anterolateral margins bearing sparse, erect, yellow, hair-like setae; base weakly bisinuate.

Elytra with sides sub-parallel on apical half, narrowing to subquadrate, smooth apex; apex weakly emarginated at suture. Margin of apical edge bearing large, coarse punctures. Disc glabrous, smooth, shining; interstriae weakly impressed, more than twice width of striae, punctures uniseriate, smaller than those of striae; striae weakly impressed. Declivity bearing sparse, short, erect, yellow setae. Metepimeron half-length of metanepisternum.

Venter. Apical margin of ventrite 1 rounded, marked by weak carina on ascendant part of venter, more strongly marked laterally. Ventrite 2 nearly perpendicular to ventrite 1; surface reticulate, shagreened, dull, finely punctate; punctures small, fine, shallow punctures; covered with sparse setae that are about twice size of a puncture; surface convex; armed with large conical median spine, apex rounded; lateral margins of ventrites 2-3 and ventrite 4 unarmed. Ventrite 5 carinate ridge closer to apical margin of segment; length of ventrite 5 less than combined lengths of ventrites 3 and 4; setal patch and median depression absent.

Female.

2.3-3.0 mm long (mean = 2.3 mm; n = 12); 2.3-2.7 times as long as wide. Similar to male except epistoma feebly emarginate, epistomal process weakly developed, frons convex when viewed laterally, weakly longitudinally aciculate, less coarsely punctate, setae sparser, shorter, less than width of eye; weakly transversely impressed just above epistoma. Second ventrite armed with smaller, rounded, median spine.

Specimens examined.

467.

Type material.

Lectotype: male, labeled "St. Anne’s, Que., July 21, 1907" (CUIC). Lectotype designated Bright 1967: 674. Paralectotype (here designated) Eccoptogaster piceae , female, CANADA:QUEBEC: St. Anne’s, 21.VII.1907 (CUIC-1). Paratypes: CANADA:QUEBEC: Hudson, 191[sic!] (CUIC-4).

Non-type material.

CANADA:ALBERTA: Banff (CNCI-2); IX.1916 (CNCI-1); 7.IX.1967, D.E. Bright, ex. Picea glauca (CNCI-1). Cypress Hills, 16.VII.[19]32 (CNCI-3). Edmonton, 16.I.1916, Carr (CNCI-1), 27.VIII.1916 (CNCI-1), 28.VIII.1916 (CNCI-1), 5.VII.1924, (CUIC-1); 6.XII.1916 (CASC-2); 15.VII.[19]24 (CASC-2); 29.VI.[19]16, J.W. Green (CASC-3), 2.IX.[19]16 (CASC-1). [Jasper National Park], Athabasca Falls, 9.VIII.1919, J.M. Swaine (CNCI-5). Medicine Hat, 2.IX.[19]26 (CNCI-2). Seebe, 7.VII.1966, D.F.J. Hilton, ex. Picea glauca (CNCI-8). BRITISH COLUMBIA: Hixon, 9.VII.1972, D.E. Bright, ex. Picea sp. (CNCI-2). [Big Creek Provincial Park], Lorna [Lake], 6.VII.1924, G. Hopping, ex. Picea engelmannii (CASC-1), 10.VIII.1924 (CASC-1), 22.VII.1925 (CASC-1), 14.VII.1926, ex. Pinus contorta (CASC-1), 9.VII.1926 (CASC-1); 10.VII.1926, H. Richmond ex. Picea engelmannii (CNCI-1), 14.VII.1926 (CNCI-1). Pine Pass, 11.VII.1972, D.E. Bright, ex. Picea sp. (CNCI-6). Trinity Valley, 21.VII.[19]30 (CNCI-1), 29.VII.[19]30 (CNCI-1), 13.VII.1928, J.R. Howell, ex. Pinus monticolae (CASC-1); 23.VII.[19]28, H. Richmond, ex. Picea engelmannii (CASC-1). MANITOBA: Aweme, 20.IX.[19]06, E. Criddle (CNCI-1); 1.VII.1916, N. Criddle, (CNCI-2) ex. bred from spruce [= Picea sp.], 2.VII.1916 (CNCI-4); 10.VII.[19]16 (CNCI-10) ex. spruce [= Picea sp.], 27.VII.[19]10 (CNCI-20), 14.VI.1918 (CNCI-2), 15.VI.1918 (CNCI-3); 5.VII.1916 (CNCI-3); 8.VII.1916 (CNCI-6), 9.VII.1916 (CNCI-1); 31.VII.1916 (CNCI-1); 9.VIII.1916 (CNCI-1); 10.IX.1917 (CNCI-10); 11.IX.1917 (CNCI-6); 9.VI.19[18] (CNCI-1). Brandon, 28.V.1940, L. Peterson, ex. Picea canadensis (CNCI-2). Gillam, 21.VII.950, W.J. Brown (CNCI-1). Glen Souris, 5.VI.[19]23, N. Criddle (CNCI-1). Grass River Provincial Park, 27.VII.1972, D.E. Bright, ex. Pinus murrayana [= Pinus contorta murrayana] (CNCI-7). Onah, 11.VII.1924, R.M. White (CNCI-3); N. Criddle, 25.VIII.[19]72 (CNCI-1). Telford, 24.VII.1963, ex. life table plot (CNCI-1), 2.VIII.1963 (CNCI-1). Winnipeg, Hanham (USNM-1). NEW BRUNSWICK: Kouchibouguac National Park, VIII.1977, D.E. Bright, Code-6224J (CNCI-1). McGraw Brook, 10 mi W., 7.VII.[19]70, D.E. Bright, ex. Picea glauca (CNCI-1). NEWFOUNDLAND: Deer Lake, 12 mi N.E., 23.VII.[19]70, D.E. Bright, ex. Picea mariana (CNCI-11). NOVA SCOTIA: Cape Breton Highlands National Park, MacIntosh Brook, PG703866, 21.VII.1983, D.E. & J.E. Bright, ex. Picea glauca (CNCI-7); 29.VII.1983, McKenzie, ex. Picea sp. (CNCI-10). Kejimkujik National Park, 16-17.VII.1967, D.E. Bright, ex. Picea glauca (CNCI-14). ONTARIO: Carp, 5.VIII.[19]66, D.E. Bright, ex. Picea mariana (CNCI-2). Lake of the Woods, 1.VIII.1972, D.E. Bright, ex. Picea sp. (CNCI-7). Ottawa, 24.VI.1913, J.M. Swaine, ex. crawling on dying Larix sp. (CNCI-1). Rainy River District, 3.VIII.[19]24, J.F. Brimley (CNCI-1). QUEBEC: Aylmer, 12.VII.1924, B.B. Watson, ex. Picea glauca (CNCI-1); 30.VII.1924, A.R. Graham (CNCI-1). Hudson, 191[sic!] (CNCI-52). Limbor/Touranine, 27.VI.1974, R. Sexton (CNCI-1). [ Gaspésie National Park], Mount Albert, 28.VII.1954, W.J. Brown, ex. north base 650 ft (CNCI-1). St. Anne’s [ Sainte-Anne-de-Beaupré], 19.VI.[19]19 (CASC-2, CNCI-42). South March, 19.VI.1958, S.D. Hicks (CNCI-1). SASKATCHEWAN: Big River, 23.VII.1972, D.E. Bright, ex. Picea glauca (CNCI-1). Big River, 40 mi N.W., 22.VII.[19]72, D.E. Bright, ex. Picea glauca (CNCI-1). Canoe Lake, 21.VII.1972, D.E. Bright, ex. Picea glauca (CNCI-2). Christopher Lake, 5.VIII.1959, A. & J. Brooks (CNCI-1). Cypress Hills, 3.IX.1967, D.E. Bright, ex. Picea glauca (CNCI-9); 24.IX.1964 (CNCI-2). YUKON: Old Crow, 28.VI.[19]81, D.E. Bright (CNCI-5). UNITED STATES:ALASKA: [North Slope Borough]: Prudhoe Bay Rd, 8 mi N., South Fork Koyukuk River, 67°13'N, 150°07'W, 1000 ft [sic!], 8.VII.1978, Smetana, Campbell (CNCI-1). Fairbanks North Star Borough: Fairbanks, 2.VIII.[19]55, W.F. McCambridge, ex. Picea glauca (DEBC-7). CALIFORNIA:Siskiyou Co: Callahan, 7 mi N.W., 16.VI.[19]63, D.E. Bright, ex. Picea engelmannii (DEBC-9, EMEC-6). Happy Camp, 18 mi N., 31.VII.[19]63, D.E. Bright, ex. Picea engelmannii (DEBC-4, EMEC-7). COLORADO:Denver Co.: Denver, Union Pacific, 14.IX.2000, USDA APHIS, ex. Lindgren funnel APEtOH Lure (CSUC-1). Larimer Co.: Livermore, 10.IX.2009, K. Smith, USDA APHIS, ex. Lindgren funnel APEtOH Lure, (CSUC-1). Roosevelt National Forest, Chambers Lake, 11.VIII.[19]68, 9200ft, L.A. Kelton (CNCI-1). MAINE: [Oxford Co.]: Wilsons Mills, 9.VIII.[19]70, D.E. Bright, ex. Picea sp. (CNCI-1). MASSACHUSETTS: [Norfolk Co.]: Dover, 8.VII.1933, C.W. Collins, ex. reared from blue spruce [= Picea pungens ] (USNM-11). MINNESOTA:Cook Co.: Superior National Forest, Hwy 12 nr. Seagull Guard Station, 48°6'29"N, 90°50'12"W, 23. VI– 9.VII.2003, K.J.K. Gandhi, ex. Lindgren funnel trap in Pinus banksiana , wind-disturbed-salvaged-logged, site D (CASC-1). Mille Lacs Co.: 2.VII.[19]36, H.R. Dodge, ex. under bark of tamarack tree [= Larix sp.] (CASC-2). MONTANA: Glacier National Park, 15.VII.[19]29 (CUIC-1). NEW MEXICO: [Taos Co.]: Red River, 3 mi W., C.C. Hoff (AMNH-1). NORTH DAKOTA:Bottineau Co.: S30 T162 R75, Hopk. U.S. 56561-A, 27.V.1973, A.D. Tagestad, ex. collected from Picea glauca densata (USNM-3). Rolette Co.: S15 T162 R69, Hopk. U.S. 56446, 19.V.[19]72, A.D. Tagestad, ex. collected from Picea pungens (USNM-2). OREGON: [Jefferson Co.]: Suttle Lake, 4 mi W., 3.IX.[19]39, Schuh, Gray, ex. Picea engelmannii (AMNH-12, FMNH-3). [Unspecified County]: Blue Mountains, 13.VII.[19]14, W.J. Chamberlain, ex. Picea engelmannii (CNCI-2). SOUTH DAKOTA:Lawrence Co.: near Leads, Brownsville Rd, N44.2922°, W103.7828°, 5650 ft, 27.VII.2004, K.P. Dole, ex. Picea glauca (MSUC-14). [Unspecified County]: Black Hills, 7.VII.[19]75, D.E. Bright, ex. Picea glauca (CNCI-5). UTAH: [Daggett Co.]: Mckee Draw, Ashley National Forest, 16.VI.1960, ex. Picea pungens (USNM-1). [Unspecified County]: Logan Canyon, S27 T13 NR4, 6.VII.1948, S.L. Wood, ex. Picea engelmannii (USNM-8). WYOMING:Carbon Co.: [Medicine Bow National Forest], Mirror Lake, 4 mi W., 6.IX.2010, D.E. Bright, B.A. Barr, ex. Picea engelmannii branches (DEBC-1); [Medicine Bow National Forest] Snowy Mountains, WY130, Lake Marie, N41°19.965', W106°19.516', 3208 m, 26.VII.2011, S.M. Smith, D.E. Bright, B.A. Barr, ex. emerged 1-5.IX.2011, ex. Picea engelmannii (MSUC-36). Johnson Co.: Buffalo, 16 km SW, 20.VI.1968, S.L. W[ood], ex. Picea engelmannii (USNM-1).

Distribution.

CANADA: Alberta, British Columbia, Manitoba, New Brunswick, Newfoundland, Northwest Territories, Nova Scotia, Ontario, Prince Edward island, Quebec, Saskatchewan, Yukon. UNITED STATES: Alaska, California, Colorado, Idaho, Maine, Massachusetts, Michigan, Minnesota, Montana, New Mexico, New York, North Dakota, Oregon, South Dakota, Utah, Washington, Wisconsin, Wyoming (Fig. 44).

Hosts.

Most spruce species including Picea breweriana S. Watson (Brewer spruce), Picea engelmannii Parry ex Engelm. (Engelmann spruce), Picea glauca (Moench) Voss (white spruce), Picea mariana (Mill.) B.S.P. (black spruce), Picea pungens Engelm. (blue spruce), and Picea rubens Sarg. (red spruce). This species rarely attacks Larix spp. (larch) and Abies balsamea (L.) Mill (balsam fir).

Biology.

Scolytus piceae infests dead and dying limbs ( Chamberlin 1939; Bright and Stark 1973) and is commonly found in branches of fallen spruce and suppressed limbs of standing hosts (Smith, pers. obs.).

The adult gallery is parallel to the grain of the wood and bayonet shaped (Fig. 24). From the central nuptial chamber, one egg gallery extends to the grain of the wood and the other egg gallery is slightly transversely extended and then extends parallel to the grain. The nuptial chamber is oblique to the egg galleries. The adult gallery equally scores the sapwood and cambium but in some instances may only lightly score the sapwood. Adult galleries average 5.0-8.0 cm in length. Ten to 30 egg niches are widely spaced and deeply score the sapwood. Larvae extend their mines perpendicular to the egg gallery before diverging in a fan shaped pattern. Pupation may occur under the bark or in the sapwood ( Edson 1967; Bright and Stark 1973). There is likely one generation per year ( Bright and Stark 1973; Furniss and Johnson 2002).

Remarks.

The female paralectotype has been returned to CUIC from the CNCI following the repositories listed in Swaine (1910).