Scolytus fagi Walsh, 1867

Smith, Sarah M. & Cognato, Anthony I., 2014, A taxonomic monograph of Nearctic Scolytus Geoffroy (Coleoptera, Curculionidae, Scolytinae), ZooKeys 450, pp. 1-182 : 26-27

Taxon classification Animalia Coleoptera Curculionidae

Scolytus fagi Walsh, 1867 Fig. 18

Scolytus fagi Walsh, 1867: 58.

Diagnosis.

Both sexes of Scolytus fagi are distinguished from Scolytus mali and Scolytus muticus by the rugose-reticulate frons that is covered by uniformly distributed setae.

Description (male).

3.3-5.5 mm long (mean = 4.45 mm; n = 20); 1.96-2.75 times as long as wide. Color dark red-brown to black, antenna light brown. Pronotum typically same color as elytra.

Head. Epistoma weakly, broadly emarginated; epistomal process absent; median area above mandibles bearing dense patch of long, yellow, hair-like setae. Frons appearing flattened when viewed laterally, slightly transversely impressed just above epistoma and along median line; rugose-reticulate, strongly punctate; punctures small, 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, thinner on apical half, 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, punctulate, punctures moderately abundant, larger, coarse 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 weakly rounded, smooth apex; apex weakly emarginated at suture. Margin of apical edge bearing small, fine punctures. Disc smooth, shining; interstriae not impressed, more than twice width of striae, punctures uniseriate, smaller than those of striae, punctures bearing short recumbent yellow setae slightly longer than size of a puncture (may be abraded); striae moderately impressed. Declivity bearing sparse, short, erect yellow setae. Metepimeron half-length of metanepisternum.

Venter. Apical margin of ventrite 1 weakly elevated above base of ventrite 2. Ventrite 2 nearly perpendicular to ventrite 1; surface smooth, shining, finely punctate; punctures large, fine, shallow; surface flattened; setae semi-recumbent, short, about half length of segment 3 or less; apical margin unarmed; lateral margins of ventrites 2-3 and ventrite 4 unarmed. Ventrite 5 unarmed; length of ventrite 5 greater than combined lengths of ventrites 3 and 4; setal patch absent, median depression present.

Female.

3.9-5.6 mm long (mean = 4.65 mm; n = 20); 1.9-2.8 times as long as wide. Similar to male except epistoma feebly emarginated, epistomal process absent, frons convex when viewed laterally, weakly longitudinally strigate-punctate, setae shorter, less than width of eye and sparse; weakly transversely impressed just above epistoma and between inner apices of eyes. Second ventrite unarmed.

Specimens examined.

74.

Type material.

Neotype Scolytus fagi Walsh: male, labeled "Galesburg, Illinois, Liebeck Collection" (MCZC). Neotype designated Smith and Cognato 2010b: 36.

Non-type material.

CANADA:ONTARIO: Point Pelee National Park, 27.IX.1989, K. Dunster, ex. Celtis tenuifolia (CNCI-9). UNITED STATES:MISSISSIPPI: [Sharkey Co.]: Rolling Fork, VIII.1976, J.D. Solomon, ex. Nuttall oak [= Quercus sp.] (USNM-1). PENNSYLVANIA:Cumberland Co.: Roadway Dr @ Schneider Dr, 40.229030°N, 77.111580°W, 26.VI.2009, L.R. Donovall, (MSUC-25), 29.V.2009, ex. Lindgren-alpha pinene/EtOH (MSUC-4), 29.V.2009, ex. Lindgren-EtOH (MSUC-1). Dauphin Co.: Wildwood on Industrial Rd, 40.316325°N, 76.888783°W, 6.VIII.2009, S.-E. Spichiger, ex. Lindgren-EtoH (MSUC-2). Lancaster Co.: 7031 Elizabethtown Rd, 40.182583°N, 76.498783°W, 23.VII.2009, ex. Lindgren-BEBB/EtOH (MSUC-1). York Co.: 400 Mundis Rd, 40.030170°N, 76.705330°W, 10.VI.2009, S. Rebert, ex. Lindgren-alpha/EtOH (MSUC-4). TEXAS: [Colorado Co.]: Columbus, [18]88 (MSUC-4, USNM-15). [Unspecified county]: (USNM-3). Fort Worth, 31.VII.[19]12, ex. bred from hackberry [= Celtis sp.] (USNM-4).

Distribution.

CANADA: Ontario. UNITED STATES: Illinois, Kansas, Mississippi, Ohio, Pennsylvania, Texas (Fig. 19).

Hosts.

Celtis occidentalis L. (common hackberry), Celtis tenuifolia Nutt. (dwarf hackberry), Celtis laevigata Willd. var. texana Sarg. (Texan sugarberry), Fagus grandifolia Ehrh. (American beech), and Quercus spp. (oak).

Biology.

The gallery has been reported as very confused and undecipherable. Larvae were reported boring in the wood. In addition, the species did not appear to colonize healthy trees ( Packard 1890). Smith and Cognato (2010a) summarized all information known about this species.

Remarks.

This species is very rarely encountered. Most museum collections occurred in the early 1900's and most recent collections have been from Lindgren funnel traps. There are many gaps in the known distribution of Scolytus fagi but the species likely occurs throughout the eastern US associated with its host trees.