Cyrtinus umbus Martins & Galileo, 2009

Bezark, Larry G. & Santos-Silva, Antonio, 2023, Expanding knowledge of American Cerambycidae (Coleoptera): new species, new records, and morphological variations, Papéis Avulsos de Zoologia 63, pp. 1-19 : 15-18

Cyrtinus umbus Martins & Galileo, 2009 ( Fig. 6 )

Cyrtinus umbus Martins & Galileo, 2009: 66 .

Redescription: Male (based on a dark specimen). Head capsule black dorsally and laterally, dark-brown on frons and ventrally; ventral mouthparts reddish brown, except yellowish-brown apex of last palpomeres; anteclypeus dark brown posteriorly, testaceous anteriorly; labrum dark reddish brown posteriorly, yellowish-brown anteriorly; scape reddish brown on basal ⅔, brown on apical third; pedicel and antennomeres III-VII orangish brown; antennomere VIII orangish brown on basal ⅔, brown on apical third;antennomere IX orangish brown basally,dark brown on remaining surface; antennomeres X-XI dark brown. Pronotum and sides of prothorax black; ventral surface of prothorax dark brown except black margins. Ventral surface of meso- and metathorax dark brown, with some areas blacker. Scutellum black. Elytra black, except transverse dark reddish-brown macula on anterior third, almost reaching suture and epipleural margin, gradually narrowed toward suture dorsally and distinctly narrowed laterally toward epipleural margin. Coxae reddish brown. Femoral peduncle orangish brown and femoral club dark brown. Tibiae reddish brown, more orangish brown depending on light intensity. Tarsi mostly brown, except dark brown tarsomere V. Abdominal ventrites blackish, except brown apex of ventrites 1-4.

Head: Frons ( Fig. 6D ) densely, very finely rugose-punctate;with sparse,bristly white pubescence;with one long, erect dark brown seta close to superior area of eyes. Area between antennal tubercles and upper eye lobes sparsely, finely punctate; with sparse white pubescence,absent centrally between antennal tubercles, and a few long, erect dark-brown setae interspersed laterally. Remaining surface of vertex with very sparse, minute punctures, except some coarser and deeper punctures centrally close to pronotum; glabrous.Area behind upper eye lobes with a few short, decumbent white setae close to eye, glabrous on remaining surface. Area between eye lobes and behind superior region of lower eye lobes glabrous; inferior region of lower eye lobes with a few long, erect white setae and one long, erect dark seta near eye, glabrous on remaining surface. Genae ( Fig. 6D ) about 1.5 times longer than lower eye lobe; finely, transversely striate, with a few fine punctures interspersed toward ventral surface, obliquely striate-punctate toward frons and clypeus, except smooth apex; with a few moderately short, erect white setae and one long, erect dark-brown seta about middle, except glabrous apex. Wide central area of postclypeus with sculpturing as on frons close to it, smooth close to anteclypeus; with sparse, erect, both long and dark brown and moderately short and white setae. Sides of postclypeus smooth, glabrous. Labrum coplanar with anteclypeus at posterior half, inclined at anterior half; densely, somewhat coarsely, shallowly punctate on posterior half, smooth on anterior half; with a few short, decumbent white setae and long, erect dark-brown setae on posterior third,erect setae forming transverse row, sparse, long whitish setae directed forward about middle and laterally, and fringe of short yellowish-white setae on anterior margin. Gulamentum smooth, glabrous. Distance between upper eye lobes 0.30 times distance between outer margins of eyes; in frontal view, distance between lower eye lobes 0.67 times distance between outer margins of eyes. Antennae 2.0 times elytral length ( Fig. 6A ), reaching elytral apex at middle of antennomere IX. Scape ( Fig. 6 A-B) arched, gradually widened toward apex, especially from middle; sparsely, finely punctate, almost smooth ventrally; with sparse, both white and yellowish pubescence dorsally, almost absent laterally, absent ventrally; with long, erect yellowish setae interspersed dorsally, and sparse, long, erect brown setae ventrally, longer than dorsal setae. Pedicel and antennomeres III-VIII with sparse white pubescence; with moderately, long, erect white setae interspersed dorsally; pedicel and antennomere III with sparse, long, erect brown setae ventrally; ventral apex with tuft of very long, both brown and yellowish-brown setae directed backward. Antennomeres IX-XI with abundant dark-brown pubescence, sparser ventrally on IX; with short, abundant, bristly white setae interspersed; with somewhat long, erect white setae interspersed, more abundant apically on XI; apex of IX-X with tuft of very long dark brown setae directed backward. Antennal formula (ratio) based on length of antennomere III: scape = 2.33; pedicel = 0.47; IV = 1.27;V = 1.13;VI = 1.13;VII = 1.07;VIII = 1.00; IX = 0.93; X = 0.93; XI = 1.00.

Thorax: Prothorax distinctly longer than wide; posteri- or constrictions well marked; sides slightly, gradually narrowed and sinuous from anterolateral angles to posterior constriction. In lateral view ( Fig. 6C ), pronotum distinctly lower on posterior quarter; sides of anterior seventh microsculptured, these areas gradually narrowed toward center, where they are fused; with sparse, coarse punctures from anterior margin to posterior constriction, punctures slightly more abundant anteriorly; each coarse puncture with long, erect dark-brown seta; sides of the rugose anterior region with a few short, decumbent white setae; area of posterior constriction smooth, glabrous; posterior seventh transversely, finely striate, with sparse fine punctures interspersed, with somewhat long, bristly white setae, more abundant laterally, and a few long, erect dark-brown setae interspersed. Sides of prothorax obliquely striate-punctate anteriorly, subsmooth on wide central area, finely, sparsely punctate close to posterior margin; with a few somewhat short, bristly white setae anteriorly and posteriorly, absent on wide central area; with a few long, erect dark-brown setae on anterior half. Prosternum sparsely,somewhat finely punctate laterally, slightly rugose-punctate centrally on posterior half; with sparse, bristly, both white and yellowish setae laterally and anteriorly, setae somewhat abundant posterocentrally; anterior margin with sparse fringe of short whitish setae. Prosternal process slightly rugose-punctate; lateral margins slightly elevated on anterior ⅔; with somewhat abundant whitish pubescence not obscuring integument; with a few long, erect dark-brown setae interspersed; narrowest area 0.31 times procoxal width. Mesoventrite with sparse whitish pubescence centrally, glabrous laterally. Mesanepisternum with dense white pubescence; mesepimeron with abundant whitish pubescence not obscuring integument, pubescence almost absent close to elytron, whiter toward procoxal cavity. Mesoventral process gradually, slightly narrowed toward truncate apex; with somewhat sparse whitish pubescence; apex 0.55 times mesocoxal width. Metanepisternum mostly glabrous. Sides of metaventrite with somewhat abundant white pubescence posteriorly; remaining surface with sparse, decumbent white setae. Scutellum with dense white pubescence. Elytra: Anterior third, sparsely, coarsely punctate; posterior ⅔ very sparsely, finely punctate; in lateral view, slightly inclined on anterior third, distinctly convex on posteri- or ⅔; centrobasal crest ( Fig. 6E ) gibbosity-shaped; sides of dorsal surface of anterior seventh, with sparse tuft of white setae; anterior quarter of dorsal surface with transverse white pubescent band from middle to near suture; apex of anterior third with transverse, somewhat sinuous white pubescent band, from middle of dorsal surface to epipleural margin; posterior half with sparse white pubescence laterally and apically; with sparse, very long, erect dark-brown setae throughout. Legs: Dorsal surface of femoral club with somewhat dense white pubescence; remaining surface sparse, decumbent white setae.Protibiae with sparse,bristly white setae dorsally and laterally, almost absent on basal third of ventral surface, and dense,bristly yellowish-brown pubescence ventrally on apical ⅔. Meso- and metatibiae with abundant, somewhat bristly white pubescence ventrally, sparse on apical ⅔ of sides, almost absent on basal third of sides and ventral surface, and abundant, bristly yellowish pubescence on posterior ⅔ of ventral surface. Dorsal surface of tarsi with sparse white pubescence.

Abdomen: Ventrites 1-4 ( Fig. 6B ) with sparse, somewhat long, suberect yellowish-white setae, except glabrous apex. Ventrite 5 with somewhat abundant white setae not obscuring integument, except yellowish-brown setae laterally and apically, and long, erect dark brown setae interspersed on posterior half; apex rounded.

Variation in dark specimens: Antennomere VIII orangish brown on basal half, dark brown on apical half; ventral surface of pro- and mesothorax orangish brown; light area of the elytra with variable shape and size, from reddish brown to orangish brown; basal area of the elytra dark brown; tibiae brown.

Dimensions in mm (3 males): Total length, 4.00/2.90/3.35/4.00; prothoracic length, 0.65/0.80/1.00; anterior prothoracic width, 0.60/0.65/0.85; posterior prothoracic width, 0.55/0.60/0.75; maximum prothoracic width, 0.65/0.70/0.90; humeral width, 0.80/0.95/1.20; elytral length, 1.80/1.90/2.45.

Material examined (only dark specimens listed): COSTA RICA, Puntarenas (new province record): 11-18 km N Pavones, 2 males, 14.I.1989, F. T. Hovore leg. ( LGBC). PANAMA (new country record), Panama: 12 km N El Llano, 1 male, 24.I.1993, F. T. Hovore leg. ( MZSP).

Remarks: Martins & Galileo (2009) described C. umbus based on two specimens (unknown sex) from Costa Rica. The two specimens have the prothorax and entire anterior third of the elytra orangish brown. The three specimens examined have the prothorax entirely dark in two specimens, black dorsally, dark brown ventrally, and black dorsally and laterally, and orangish brown in the third specimen. However, these specimens have the oth- er morphological features identical to that of the holotype and paratype.

Cyrtinus umbus is similar to C. howdeni Wappes, Santos-Silva & Nascimento, 2020 , but differs as follows: posterior third of antennomeres III-IV slightly widened; centrobasal crest of the elytra slightly elevated, gibbous; sides of the area of the centrobasal crest with white setae. In C. howdeni , the basal third of the antennomeres III-IV are distinctly widened, centrobasal crest of the elytra is elevated, subtriangular, and sides of the area of the centrobasal crest without white setae. The studied species differs from C. melzeri Martins & Galileo, 2009 by the shape of the centrobasal crest (conical in C. melzeri ); from C. mockfordi Howden, 1959 by the pronotum shiny, microsculptured only close to anterior margin (opaque, almost entirely microsculptured in C. mockfordi ), almost without decumbent setae on basal half (with somewhat abundant whitish setae in C. mockfordi ), and elytra subparallel-sided on anterior ⅔ (rounded from humerus to apex in C. mockfordi ); from C. opacicollis (Bates, 1885) by pronotum mostly smooth and shiny (opaque and entirely microsculptured in C. opacicollis ), and shape of the centrobasal crest of the elytra (elevated and conical in C. opacicollis ); from C. hispidus Martins & Galileo, 2009 and C. penicillatus (Bates, 1885) by the shape of the centrobasal crest of the elytra (elevated, with dense tuft of long and erect setae apically in C. hispidus and C. penicillatus ); from C. bordoni Joly & Rosales, 1990 and C. fisheri Wappes, Santos-Silva & Nascimento, 2020 by the shape of the centrobasal crest of the elytra (conical and elevated in C. bordoni and C. fisheri ); from C. farri Howden, 1960 , by the elytra not pubescent basally (pubescent in C. farri ), and with transverse white pubescent band close to suture (absent in C. farri ); from C. meridialis Martins & Galileo, 2010 , C. peruviensis Audureau, 2017 , and C. mussoi Joly & Rosales, 1990 by the elytra with three white pubescent areas on the anterior third (only one transverse pubescent band in C. meridialis , C. peruviensis , and C. mussoi ).

Figures

Figure 6. Cyrtinus umbus Martins & Galileo,2009,male from Costa Rica:(A) Dorsal habitus;(B)Ventral habitus;(C) Lateral habitus;(D) Head,frontalview;(E) Elytral base,lateral view.