Gortonia sumideroensis Wappes and Santos-Silva, 2020

Wappes, James E. & Santos-Silva, Antonio, 2020, New species of Trachyderini from Mexico and Central America (Coleoptera: Cerambycidae: Cerambycinae), Insecta Mundi 2020 (822), pp. 1-11 : 5-8

Gortonia sumideroensis Wappes and Santos-Silva , new species

( Fig. 10–16 )

Description. Holotype male. Head, prothorax, and ventral surface of meso- and metathorax dark brown, almost black, with slightly violaceous reflections on some areas; parts of mouthparts dark reddish-brown; basal antennal segments dark brown, with slightly bluish reflections, and remaining segments gradually brown toward antennal apex; elytra dark blue metallic; profemora yellowish-brown with irregular dark reddish areas interspersed; meso- and metafemora almost black on basal half and apex, dark reddish-brown on remaining surface; distal half of tibiae brown, except black apex; tarsi dark brown; central area of abdominal ventrite II brown, central area of abdominal ventrite III dark reddish-brown centrally, and abdominal ventrite V dark brown with irregular dark reddish-brown areas interspersed.

Head. Frons finely, abundantly rugose-punctate, except smooth triangular plate close to clypeus; with grayish-white pubescence not obscuring integument (whiter depending on light intensity), with triangular plate glabrous. Area between antennal tubercles and beginning of upper eye lobes finely, abundantly punctate; with short, sparse, bristly grayish-white setae (whiter depending on light intensity), sparser toward upper eye lobes; remaining surface of vertex and superior area behind upper eye lobes finely, densely punctate (punctures partially confluent behind eyes), except almost smooth narrow central area of vertex, widely, triangularly expanded close to prothorax; with a few minute grayish-white setae between upper eye lobes, glabrous on remaining surface. Remaining surface of area behind upper eye lobes smooth and glabrous; smooth behind lower eye lobes close to superior 2/3 of eye, finely sparsely punctate on inferior third close to eye, coarse, densely punctate on entire area close to prothorax; with a few short yellowish-brown setae close to eye on inferior third, remaining surface glabrous. Genae finely, somewhat abundantly punctate close to eye, apex smooth (this area widened toward clypeus); with short, sparse grayish-white setae on punctate area (whiter depending on light intensity). Median groove distinct from clypeus to area between antennal tubercles. Antennal tubercles finely, abundantly punctate with apex smooth; with short, decumbent, sparse yellowish-brown setae, impunctate area glabrous. Postclypeus finely, somewhat sparsely punctate on wide central area, smooth laterally; with short, bristly grayish-white setae (whiter depending on light intensity), and a few long, erect setae of same color interspersed on wide central area, impunctate area glabrous. Labrum smooth, glabrous, coplanar with anteclypeus on posterior third, oblique, with long, erect yellowish-white setae directed forward on anterior 2/3, and short fringe of golden setae on anterior margin. Gulamentum smooth, glabrous on center of posterior 2/3, striate-punctate, glabrous on sides of posterior 2/3; depressed, opaque, minutely, abundantly punctate, with grayish-white pubescence, and long erect setae of same color interspersed on anterior third. Distance between upper eye lobes 0.54 times length of scape (0.30 times distance between outer margins of eyes); in frontal view, distance between lower eye lobes 0.94 times length of scape (0.52 times distance between outer margins of eyes). Antennae 2.1 times elytral length, reaching elytral apex about middle of antennomere VIII. Scape finely, abundantly punctate dorsally and laterally, apex of dorsal surface smooth, sides of apical area sparsely punctate, ventrally sparsely punctate; with short, abundant, brownish setae on punctate area of dorsal and lateral surfaces, with a few short, erect grayish-white setae interspersed dorsally, sparse brownish setae throughout and a few long, erect grayish-white setae near apex ventrally. Pedicel with sparse brownish pubescence. Antennomeres finely, abundantly punctate with apex smooth; with brownish pubescence not obscuring integument, with a few short erect yellowish setae dorsally, and long, erect, abundant dark setae ventrally. Antennomere IV finely, abundantly punctate except smooth apex (punctures shallower than on III), with sparse yellowish-white pubescence, and long, erect dark setae ventrally (dark setae distinctly sparser than on III). Remaining antennomeres with yellowish-white pubescence, somewhat denser toward XI, and short, erect, sparse yellowish setae throughout (erect setae longer on V–VI). Antennal formula (ratio) based on length of antennomere III: scape = 0.56; pedicel = 0.10; IV = 0.98; V = 0.97; VI = 1.06; VII = 1.10; VIII = 1.04; IX = 0.95; X = 0.85; XI = 1.01.

Thorax. Prothorax as long as wide; sides uniformly rounded. Pronotum finely, sparsely punctate ( Fig. 14 ), except smooth central area; glabrous, except a few short yellowish setae on sides of posterior area. Sides of prothorax finely, sparsely punctate, with short, sparse grayish-white setae close to pronotum, coarser, abundantly punctate, with abundant, bristly grayish-white setae toward prosternum (setae gradually denser and longer toward prosternum), except subsmooth area close to anterior margin (this area gradually widened toward prosternum). Prosternum finely, sparsely punctate on posterior half, minutely, transversely striate on anterior half; with both short and long, grayish-white setae, denser laterally. Prosternal process with short, sparse grayishwhite setae anteriorly, denser posteriorly; narrowest area 0.4 times width of procoxal cavity. Mesoventrite with short, sparse grayish-white pubescence centrally, denser, longer laterally. Mesanepisternum, mesepimeron, and metanepisternum with abundant, bristly grayish-white setae. Mesoventral process abruptly elevated basally; with sparse grayish-white pubescence basally which is denser and longer posteriorly; narrowest area 0.7 times width of mesocoxal cavity. Metaventrite with both short and long, abundant grayish-white setae, sparser toward glabrous central area. Scutellum minutely, sparsely punctate basally, smooth on remaining surface; with a few minute grayish-white setae basally, glabrous on smooth area. Elytra. Coarsely, densely punctate throughout, punctures sparser anteriorly ( Fig. 15 ) than on remaining surface ( Fig. 16 ); with long, suberect, abundant yellowish-brown setae throughout (appearing to be darker due to integument color), except posterior area with thicker, longer black setae; apices individually rounded. Legs. Profemora subfusiform, finely, very sparsely punctate, with short, decumbent, very sparse grayish-white setae dorsally and laterally, setae longer and bristly ventrally. Mesofemora subpedunculate, arched on basal third; finely, sparsely punctate; with sparse, grayish-white setae dorsally and laterally, slightly longer and more abundant ventrally (setae yellower toward apex). Metafemora slightly arched on anterior quarter; finely, abundantly punctate throughout; setae as on mesofemora, but yellower just after base. Protibiae with a few short yellowish-white setae dorsally and laterally, and dense, bristly yellowish-brown setae ventrally; meso- and metatibiae with sparse yellowish-white setae dorsally and laterally, dense, yellowish-brown ventrally on apex of mesofemora, dense, dark brown on apex of metafemora; meso- and metafemora with long, erect, thick black setae ventrally. Metatarsomere I 1.4 times longer than II+III, about 0.38 times length of metatibiae; metatarsomere II 0.46 times length of I; metatarsomere V 0.56 times length of I.

Abdomen. Ventrites with both short and long grayish-white setae, more abundant laterally, except glabrous apex of I–IV. Ratio of ventrites, based on V: I (including abdominal process), 1.95; II = 1.00; III = 0.86; IV = 0.86.

Dimensions in mm (holotype male). Total length, 9.80; prothoracic length, 1.80; anterior prothoracic width, 1.40; posterior prothoracic width, 1.75; maximum prothoracic width, 1.85; humeral width, 2.00; elytral length, 6.80.

Type material. Holotype male from MEXICO, Chiapas: Sumidero Canyon, near Tuxtla Gutiérrez , 4,000 ft., 6–8.II.1986, J.E. Wappes col. ( FSCA, formerly ACMT).

Etymology. Named for El Sumidero Canyon, Chiapas, Mexico where the holotype was collected.

Remarks. According to Hovore (1987): “The elongate, cylindrical form, long posterior legs, long, slender antennae, smooth, unarmed prothorax, and metallic elytra distinguish Gortonia from all other purpuricenine genera.” In fact, only the smooth prothorax allows separating Gortonia from Ischnocnemis Thomson, 1864 . Among the species currently included in Ischnocnemis , there are species with metallic elytra, and the length of the metatarsomere I is variable. Thus, the separation and hence the validity of these two genera is questionable. Even so, without a revisionary study of Ischnocnemis (which is beyond the scope of this descriptive paper), to be sure about the eventual synonymy, we prefer to leave them here as separate genera. The separation between Gortonia and Parabatyle Casey, 1912 is also problematic, because all or nearly all features defining the former are also present in the latter. The only reliable difference found is the elytral apex truncate in Parabatyle and rounded in Gortonia .

Gortonia sumideroensis differs from G. linsleyi Hovore, 1987 by the elytral sculpturing and pubescence less dense. In male of G. linsleyi , the elytral sculpturing and pubescence are denser (see photograph on Bezark 2020). Additionally, all known specimens of G. linsleyi have the prothorax primarily reddish-orange versus entirely dark in G. sumideroensis . According to the original description, the distance between upper eye lobes in the male of G. linsleyi is equal to “about the diameter of antennal scape.” In G. sumideroensis , the distance is greater (about 1.2 times maximum diameter of the scape).

Figures

Figures 10–16. Gortonia sumideroensis, holotype male. 10) Dorsal habitus. 11) Ventral habitus. 12) Lateral habitus. 13) Head, frontal view. 14) Pronotal sculpturing. 15) Elytral sculpturing in anterior quarter. 16) Elytral sculpturing in middle area.