Scolytus hermosus Wood, 1968

Smith, Sarah M. & Cognato, Anthony I., 2014, A taxonomic monograph of Nearctic Scolytus Geoffroy (Coleoptera, Curculionidae, Scolytinae), ZooKeys 450, pp. 1-182 : 34-35

Taxon classification Animalia Coleoptera Curculionidae

Scolytus hermosus Wood, 1968 Fig. 33

Scolytus hermosus Wood, 1968: 12.

Diagnosis.

Both sexes resemble the Scolytus silvaticus female. The female is distinguished by having a weakly developed epistomal process and the male is distinguished by having the apical margin of ventrite 1 produced, forming a carinate lip along the basal margin of ventrite 2 that is twice as produced as thick and by the host genus, Abies .

Description (male).

3.0 mm long (n = 1); 1.5 times as long as wide. Head, antennae, pronotum, and abdominal venter dark red-brown, elytra and legs yellow-brown to light brown. Pronotum typically darker than elytra.

Head. Epistoma weakly emarginated; epistomal process weakly developed, low; median area above mandibles bearing dense patch of long, yellow, hair-like setae. Frons appearing convex when viewed laterally, slightly transversely impressed just above epistoma and between inner apices of eyes; moderately, finely, longitudinally aciculate-punctate; aciculations converging at epistoma; 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, elongate, almost subquadrate, 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 moderately emarginated at suture. Margin of apical edge bearing large, coarse punctures. Disc smooth, shining; interstriae not impressed, more than twice width of striae, punctures uniseriate, smaller than those of striae, punctures bearing sparse, long, erect, yellow hair-like setae (may be abraded); striae weakly impressed. Declivity bearing sparse, short, erect yellow setae. Metepimeron half-length of metanepisternum.

Venter. Apical margin of ventrite 1 produced, forming carinate lip along basal margin of ventrite 2 that is twice as produced as thick, basal margin of ventrite 2 appearing impressed. Ventrite 2 nearly perpendicular to ventrite 1; surface shagreened, dull, finely punctate; punctures small, fine, shallow; setae moderately abundant, recumbent, short, about four times length of a puncture; surface weakly concave; apical margin armed with broad median denticle, occasionally absent; lateral margins of ventrites 2-3 and ventrite 4 unarmed. Ventrite 5 carinate ridge closer to apical margin of segment; length of ventrite 5 greater than combined lengths of ventrites 3 and 4; setal patch and median depression absent.

Female.

2.5-3.5 mm long (mean = 3.27 mm; n = 6); 2.1-2.3 times as long as wide. Similar to male except epistoma feebly emarginated, epistomal process absent, frons more strongly convex when viewed laterally, weakly longitudinally aciculate, setae sparser, shorter, less than width of eye; weakly transversely impressed just above epistoma. Apical margin of ventrite 1 weakly elevated above base of ventrite 2. Second ventrite unarmed.

Specimens examined.

27.

Type material.

Holotype Scolytus hermosus Wood: male, labeled "Tlaxco 11 mi N., 8900 ft, 9.VII.1967, S.L. W[ood], ex. Abies religiosa " (USNM). Paratypes: MEXICO: [Puebla]: Tlaxco, 11 mi N., 8900 ft, 9.VII.1967, S.L. W[ood], ex. Abies religiosa (USNM-21).

Non-type material.

MEXICO:CHIHUAHUA: La Magdalena, Hopk. U.S. 62081-B, 27.IV.1981, M.M. Furniss, ex. Abies durangensis (USNM-1). Nuevo León: Cerro Potosi, Hopk. U.S. 58615-C, 21.III.[19]74, M.M. Furniss, ex. Abies sp. (USNM-2, WFBM-1).

Distribution.

MEXICO: Chihuahua, Nuevo León, Puebla (Fig. 34).

Hosts.

Abies religiosa (Kunth) Schltdl. & Cham (sacred fir), Abies durangensis Martínez (Durango fir) and Pseudotsuga menziesii (Mirb.) Franco (Douglas fir). Abies species are likely the preferred hosts.

Biology.

There is a paucity of information regarding the biology of this uncommon species. Scolytus hermosus has been collected feeding in the cambium of large Abies slash greater than 10.0 cm in diameter ( Wood 1967) and weakened and dying large Pseudotsuga menziesii ( Cibrián Tovar et al. 1995). The adult galleries are transverse and perpendicular to the grain of the wood ( Wood 1967). This species has been reported to colonize the same material as Scolytus mundus ( Wood 1968).