Stenaspis castaneipennis Dupont, 1838

Eya, Bryan K., 2021, Recharacterization of Stenaspis Audinet-Serville, 1834 with a new species from Mexico (Coleoptera: Cerambycidae: Cerambycinae: Trachyderini), Insecta Mundi 2021 (851), pp. 1-36 : 14-16

Stenaspis castaneipennis Dupont, 1838

( Fig. 78–83 )

Stenaspis castaneipennis Dupont 1838: 52 ; White 1853: 78; Lacordaire 1869: 171; Gemminger and Harold 1872 (cat.): 2967; Bates 1880: 76 (dist.); Aurivillius 1912: 458 (cat.); Blackwelder 1946: 589 (cat.) (cat.); Chemsak et al. 1992: 86 (cat.); Monné 1994 (cat.): 34; Monné and Giesbert 1994: 152 (cat.); Noguera and Chemsak 1996: 403 (dist.); MacRae et al. 2012: 181 (dist.).

Redescription. Male: Length 21–32 mm. Form large, glabrate; integument yellowish-brown to reddish-black; head, pronotum and appendages variegated reddish-brown to black; sternum variegated yellowish-black to black, scutellum dark reddish-black to black; elytra yellowish to pale testaceous. Head with vertex and frons rugulose, irregularly punctate; genae irregularly punctate, sparsely covered with appressed pubescence; antennal tubercles prominent, apices acute; antennae exceeding elytral apices by about four segments, scape conical, coarsely separately to irregularly punctate with very short, depressed hair arising from each puncture; apices of antennomeres III–VII darker, slightly enlarged and expanded; antennomeres from apex of III laterally carinate with poriferous area on either side of carina; dorsum of antennomeres III–VI glabrate, nitid, finely, sparsely, irregularly punctate, apices densely punctate and densely clothed with short, black depressed hairs; antennomeres from VII densely clothed with short appressed pubescence; antennomere III longer than I, IV shorter than III, V longer than III, VI subequal to or longer than V, VII subequal to VI, VIII subequal to VII, IX subequal to VIII, X shorter than IX, XI longest, appendiculate at apical two-fifths. Pronotum 1.4–1.5 times as broad as long, rounded to broadly angulate at sides; anterior angles inflated, broadly rounded; disc with dorsal calli vague, two in anterior half on either side of middle, and three in basal half, one in middle and one each on either side; area between calli flattened, surface irregularly punctate, sparsely covered with long, erect, golden hairs; proepisternum inflated, finely, densely punctate, sparsely pubescent, and demarcated from prosternum and coarsely punctate elytral disc; prosternum transversely rugose with finely, densely punctate transverse subrectangular area on each side of middle; prosternal intercoxal process sparsely, irregularly punctate; mesosternum nitid, anterior half and on sides finely, densely, minutely punctate and densely pubescent with appressed, transparent hairs, posterior half irregularly punctate in middle; mesosternal intercoxal process sparsely pubescent on sides; metasternum nitid, sparsely punctate, and sparsely pubescent with long, depressed, golden hairs, metepisternum finely, densely pubescent with whitish, depressed hairs. Elytra about 2.3 times longer than broad, distinctly margined laterally; disc nitid, glabrous, separately, finely, shallowly punctate. Legs with femora slightly clavate, apical half rugulose, coarsely punctate, basal half sparsely, irregularly punctate, surface clothed with short, depressed, black hairs, outer margin with short, black, depressed bristles; tibiae slender, surface glabrate, sparsely punctate and sparsely covered with short, black, depressed hairs, inner margin with a row of short, depressed bristles in apical half. Abdomen glabrate, finely, shallowly and rather sparsely punctate in middle with suberect, golden pubescence, sides more finely, densely punctate, densely pubescent with appressed short hairs; fifth sternite truncate, slightly emarginate.

Female: 18–33 mm. Form similar to male, head, pronotum and appendages similar in coloration to male; antennae one segment shorter than elytral apex or attaining apices, scape conical, coarsely, separately punctate to finely punctate; apices of antennomeres III–V slightly enlarged, VI–XI gradually flattened, apices expanded and angulate; antennomere III longer than I, IV shorter than III, V shorter than III, VI subequal to V, antennomeres from VII–X progressively shorter, XI longer than X and subequal to IX, appendiculate at apical third. Pronotum laterally tuberculate in middle; anterior angles with obtuse callus on each side; proepisternum coarsely, densely, contiguously punctate and not clearly demarcated from prosternum and coarsely punctate pronotal disc as in male; prosternum finely to coarsely striate-punctate (without finely punctate transverse subrectangular area found in males). Legs similar to males with inner margin of femora frequently sparsely covered with long, golden, suberect hairs. Abdomen similar to male, fifth sternite rounded, vaguely indented at apex.

Materials examined. MEXICO: Oaxaca: 6 km S.E. Santiago Matatlán, HWY 190, R.M.O. Ocotepec, 16 Oct. 2005, B.K. Eya (10 males, 5 females, BKEC), 21 Oct. 2005, B.K. Eya (2 males, 7 females, BKEC); 1.7 km W Hwy. 190 on Microondas Rd. N. of Ocotepec, 6800 ft., 16°49′32″N, 96°21′42″W, on flower Viguiera dentata (Cabanilles) Sprengel (Asteraceae) T.C. MacRae (1 male, DJHC); road to Microondas Ocotepec, 6 km S. Matatlán, 16°49′32″N, 96°21′42″W, 10 Oct. 2003, 2000–2100 m. N.M. Schiff (1 male, 1 female, LGBC), 14 Oct. 2006, 6800′ flowers/foliage, C.L. Bellamy (3 males, LGBC); Sola de Vega, 1500 m 25/ 30 Sept. 2005, D.J. Curoe (1 male, 1 female, BKEC).

Discussion. According to Dupont (1838: 52), the head and thorax are variegated black and reddish; elytra smooth pale castaneous; antennae reddish with black articulation; legs reddish with apices of tarsi and femora black. The thorax is roughly similar in shape to that of S. verticalis , reddish with two lateral black bands, and anterior and posterior margin dark black; the elytra are very light reddish, longer and more parallel than in S. verticalis , less strongly punctate and more shiny. Other than the overall coloration of S. castaneipennis , this species can be differentiated by the black vittae on either side of the head and pronotal disc, much coarser, deeper punctures on the vertex, scape and pronotum ( Fig. 46 , 53 ), and the elytral discs nitid, glabrous, and separately, finely, shallowly punctate. The dark area on the pronotum of S. verticalis , if present, is mostly in the anterior half of the disc, and the punctures on the vertex, scape and pronotum are comparatively shallower and finer ( Fig. 51 ). The elytra are more coarsely, closely and deeply punctate in S. verticalis compared to S. castaneipennis . The prosternal intercoxal process of S. castaneipennis is gradually sloping and then abruptly acuminate at apex in all of specimens examined ( Fig. 46–47 ) whereas in S. verticalis the lateral profiles of the prosternal intercoxal process are variable, ranging from uniformly sloping to the apex ( Fig. 42–43 ) to concave and abruptly acuminate at the apex ( Fig. 44–45 ). The overall consistency in characteristics of S. castaneipennis can be attributed to the distribution limited to Oaxaca whereas S. verticalis is more polymorphic and widely distributed with regional variation in characters.

The females of S. castaneipennis can be differentiated from the males by the length of the antennae, shape of the antennomeres, and shape of the pronotum with more distinct lateral tubercles and broadly callused anterior angles ( Fig. 30 ). The proepisternums of females are coarsely, densely, contiguously punctate and not clearly demarcated from the prosternum and coarse punctures on the dorsum ( Fig. 31 ). The prosternum is without the finely punctate transverse subrectangular area found in males ( Fig. 32 ). Some females have more finely punctate scape, and inner margins of the femora are frequently sparsely covered with long golden hairs. Also, the apex of the fifth abdominal sternite in males is truncate and slightly emarginate, whereas females have a rounded fifth sternite which is vaguely indented at apex.

Figures

Figures 78–83. Dorsal and lateral images of Stenaspis castaneipennis Oaxaca, MEX. 78–79) Male, 32 mm. 80–81) Male, 27 mm. 82–83) Female, 28 mm.

Figures 42–50. Prosternal and mesosternal intercoxal process of Stenaspis compared to Crioprosopus and Callistochroma. 42–43) S. verticalis, male, Jalisco, MEX with uniformly sloping prosternal intercoxal process to apex that is abruptly declivous behind. 42) Lateral profile. 43) lateral-tilted profile showing gradual sloping of intercoxal process to apex. 44–45) S. verticalis, male, Puebla, MEX with prosternal intercoxal process concaved and abruptly acuminate apex. 44) Lateral profile. 45) Lateral-tilted profile showing inverted “U-shaped” sloping of intercoxal process to apex. 46–47 S. castaneipennis, male, Oaxaca, MEX with prosternal intercoxal process gradually sloping and then abruptly acuminate at apex. 46) Lateral profile. 47) Lateral-tilted profile showing gradual sloping and abrupt acumination at apex. 42–47 Mesosternal intercoxal process not protuberant, about level with coxae, and abruptly declivous in front. 48) Crioprosopus servillei Audinet-Serville, female, Tegucigalpa, HND. 48: 48a) Prosternal intercoxal process arcuate at apex. 48: 48b) Mesosternal intercoxal process without obvious projection below coxal cavity. 49) Crioprosopus wappesi Eya, male, Baja Verapaz, GTM. 49: 49a) Prosternal intercoxal process arcuate at apex. 49: 49b) Mesosternal intercoxal process level with coxae. 50) Callistochroma lampros (Bates), male, Panama Prov., PAN. 50: 50a) Prosternal intercoxal process arcuate at apex. 50: 50b) Mesosternal intercoxal process protuberant, obtusely tuberculate and extending well below plane of prosternal intercoxal process.

Figures 51–56. Scape of Stenaspis compared to Crioprosopus and Callistochroma. 51) Stenaspis verticalis, male, Puebla, MEX. 52) S. solitaria, male, Cochise Co., AZ, USA. 53) S. castaneipennis, male, Oaxaca, MEX. 54) Crioprosopus servillei, female, Tegucigalpa, HND. 55) Crioprosopus baldwini, female, Chiriquí Prov., PAN. 56) Callistochroma lampros, male, Panama Prov., PAN. 51–53) Scape of Stenaspis without excavated area in basal half. 51–52) Scape glabrate, sparsely punctate. 53) Scape coarsely, separately punctate. 54–56) Scapes of Crioprosopus and Callistochroma with excavated area in basal half.

Figures 24–32. Pronotal and prosternal characteristic of Stenaspis castaneipennis. 24–26) S. castaneipennis, male, Oaxaca, MEX with sides of pronotum rounded, disc coarsely punctate with 5 vague calli. 25) Proepisternum inflated and finely punctate (dark reddish area) clearly demarcated from coarsely punctate dorsum (black area). 27–29) S. castaneipennis, male, Oaxaca, MEX with sides of pronotum with distinct lateral tubercles. 28) Proepisternum inflated and finely punctate (reddish area) clearly demarcated from dorsum (black area). 29: 29a) Subrectangular finely punctate area of prosternum. 29: 29b) Demarcation line dividing proepisternum from finely punctate subrectangular area of prosternum. 30–32) S. castaneipennis, female, Oaxaca, MEX with side of pronotum distinctly tuberculate. 30: 30a) Anterior angles obtusely tuberculate. 31–32) Pronotal disc, proepisternum and prosternum coarsely punctate; proepisternun not demarcated from dorsum and prosternum.