Gnomidolon amazonicum, Carli & Monné & Santos-Silva & Rafael, 2025

Gnomidolon amazonicum sp. nov.

( Figs 24–27 View FIGURES 24–27 )

Description. Holotype male. Head capsule reddish brown, except antennal tubercles light reddish brown with dark-brown apex, dark-brown central area of frons, apex of sides of postclypeus, and most dark-brown apex of genae; ventral mouthparts reddish brown, except yellowish-brown apex of palpomeres; scape orangish brown, partially reddish brown apically; pedicel dark brown on basal half, reddish brown on apical half; antennomere III orangish brown, except dark-brown carinae and reddish-brown apex; antennomeres IV–VIII orange except brownish carinae and light reddish-brown apex; antennomeres IX–XI mostly reddish brown, slightly darker on XI. Prothorax orangish brown anteriorly, more reddish brown depending on light intensity, this area gradually widened from pronotum to prosternum, black on remaining surface, this area very short on prosternum; prosternal process orangish brown centrally, dark brown laterally. Central area of mesoventrite and superior region of mesanepisterna blackish, and remaining surface reddish brown; mesoventral process dark brown anteriorly, irregularly dark reddish brown posteriorly. Metanepisterna blackish anteriorly, gradually reddish brown toward apex. Metaventrite black anteriorly close to metanepisterna, reddish brown on remaining surface, more dark yellowish brown depending on light intensity, except blackish metathoracic discrimen and orange posterocentral region. Scutellum dark brown except orangish margins. Elytra with large black X-shaped macula on anterior half, not reaching anterior margin; remaining anterior quarter orangish brown, more reddish brown depending on light intensity; lateral area on anterior half, between anterior orangish brown region and black X-shaped macula light yellowish brown; area close to posterior margin of black X-shaped macula light yellowish brown; area between central light yellowish-brown band and posterior eight of dorsal surface and posterior sixth of sides orangish brown, gradually reddish brown toward its apex; remaining apical area black. Procoxae mostly dark brown; mesocoxae orangish brown anteriorly, reddish brown posteriorly; metacoxae mostly reddish brown; protrochanters mostly dark reddish brown; meso- and metatrochanters mostly reddish brown. Profemora dark brown basally, on basal 3/4 of dorsal and inner surfaces, orangish brown on remaining surface, more reddish brown depending on light intensity; mesofemora orangish brown, slightly darker apically; metafemora orangish brown, slightly darker than mesofemora, darkened apically. Tibiae mostly dark brown basally, reddish brown on remaining surface, except darkened carinae. Tarsi blackish. Abdominal ventrite 1 orangish brown except brownish apex; ventrite 2 orangish brown laterally and basally, brownish on remaining surface; ventrites 3–5 mostly dark brown.

Head. Frons densely, coarsely rugose-punctate, except longitudinally striate area close to median groove; with a few short, bristly, whitish setae and one long, erect yellowish-brown setae, on each side near eye and antennal tubercle. Area between antennal tubercles somewhat finely rugose-punctate, except smooth median groove; with a few short, decumbent yellowish-white setae. Area between antennal tubercles and upper eye lobes densely, minutely sculptured, with a few coarse, shallow punctures interspersed; with a few short, decumbent yellowish-white setae and a few long, erect yellowish-brown setae laterally. Remaining surface of vertex shiny, sparsely, coarsely punctate; with a few short, decumbent yellowish-white setae, except opaque, abundantly punctate, punctures mostly transverse, glabrous area close to prothorax. Area behind upper eye lobes densely, minutely sculptured superiorly close to eye, shiny, sparsely, coarsely punctate on remaining surface; with a few short, decumbent yellowish-white setae superiorly, glabrous on remaining surface. Area behind lower eye lobes abundantly, somewhat finely punctate close to eye, less so close to upper eye lobe, mostly smooth on remaining surface; with sparse, short, decumbent whitish setae close to eye, and with a few long, erect yellowish-brown setae interspersed, almost glabrous on remaining surface. Genae abundantly, moderately coarsely punctate, except smooth apex; with sparse yellowish-white pubescence not obscuring integument, except glabrous smooth area; with a few long, erect yellowish-brown setae interspersed. Wide central area of postclypeus abundantly, very finely striate-punctate close to frons, except one coarse puncture on each side, abundantly, finely punctate close to anteclypeus; with a few short, decumbent white setae, a few short, erect yellowish-brown setae, and one long, erect, thick yellowish-brown seta on each side. Sides of postclypeus subsmooth, glabrous. Labrum with short, suberect yellowish setae posteriorly, and dense, short yellowish-brown setae anteriorly. Antennal tubercles densely, obliquely striate frontally, very sparsely, finely punctate on remaining surface; with a few short, decumbent yellowish-white setae dorsally and posteriorly. Gulamentum smooth, glabrous on posterior half; anterior half, rugose-punctate; with sparse, short, bristly whitish setae, and a few long, erect yellowish-brown setae interspersed. Basal 2/3 of outer surface of mandibles coarsely striate-punctate; with sparse, short, decumbent, both white and yellowish setae, and a few long, erect, thick yellowish-brown setae. Central area of upper eye lobes with three rows of ommatidia; distance between upper eye lobes 0.28 times distance between outer margins of eyes; in frontal view, distance between lower eye lobes 0.4 times distance between outer margins of eyes. Antennae 2.45 times elytral length, reaching elytral apex at basal third of antennomere VIII. Scape not projected apically; somewhat coarsely rugose-punctate on basal third, sparsely, finely punctate on remaining surface, except smooth dorsal apex; with a few short, decumbent white setae; with a few long, erect yellowish-brown setae on basal half of dorsal surface and apical quarter of ventral surface; with short, erect yellowish-brown setae dorsally. Pedicel with a few short, decumbent white setae, a few short, decumbent yellowish-brown setae, longer than white setae, and a few long, erect yellowish-brown setae ventrally. Antennomeres III–XI with abundant yellowish-white pubescence not obscuring integument, except glabrous longitudinal carinae on III–X; ventral surface of III–V with long yellowish-brown setae ventrally, erect setae with two different sizes, and a few long, erect yellowish-brown setae on apex of dorsal surface; VI–X with a few long, erect yellowish-brown setae apically; VI–XI whith abundant, short, erect yellowish-white setae throughout. Antennal formula based on length of antennomere III: scape = 0.67; pedicel = 0.14; IV = 0.61; V = 0.64; VI = 0.64; VII = 0.63; VIII = 0.59; IX = 0.56; X = 0.54; XI = 0.75.

Thorax. Pronotum sparsely, minutely punctate on posterior half, with a few coarse punctures interspersed; with very sparse, minute whitish setae, absent on some areas; with a few long, erect yellowish-brown setae. Sides of prothorax almost entirely smooth, with a few short, decumbent yellowish-white setae and a few long, erect yellowish-brown setae. Prosternum sparsely, minutely, shallowly punctate; with a few minute whitish setae on posterior half, distinctly more abundant close to procoxal cavities; anterior half transversely rugose except subsmooth area close to anterior margin; with a few minute whitish setae. Prosternum with abundant yellowish-white pubescence not obscuring integument, except glabrous apical sides; narrowest area 0.23 times procoxal width. Ventral surface of mesothorax with abundant yellowish-white pubescence not obscuring integument on center of mesoventrite, pubescence distinctly denser on remaining surface, except glabrous apex of mesoventral process; apex of mesoventral process distinctly notched centrally; narrowest area of mesoventral process 0.42 times mesocoxal width. Metanepisterna with abundant yellowish-white pubescence partially obscuring integument. Metaventrite with abundant yellowish-white pubescence anteriorly and apically close to metanepisterna, and mesocoxal and metacoxal cavities; remaining surface with a few short, decumbent whitish setae, and a few long, erect yellowish-brown setae. Scutellum with dense yellowish-white pubescence. Elytra. Somewhat sparsely, coarsely punctate on basal half, punctures gradually sparser and finer toward apex on posterior half; apex truncate with moderately long spiniform projection on outer angle; with very sparse, minute whitish setae and a few long, erect yellowish-brown setae. Legs. Inner apex of profemora with short triangular projection and outer apex unarmed; inner and outer apex of mesofemora with triangular projection; inner apex of metafemora with short triangular projection and outer apex with long spine; all femora with a few long, erect yellowish-brown setae. Pro- and mesotibiae with dense, bristly dull yellow pubescence on apical 3/4 of ventral surface and apical half of inner surface; remaining surface with a few short, decumbent yellowish setae; with sparse, long, erect yellowish-brown setae, especially dorsally. Metatibiae with a few, both short and minute yellowish setae dorsally, laterally, and basal quarter of ventral surface; remaining ventral surface with dense, bristly yellowish-brown pubescence; with long, erect yellowish-brown setae throughout, erect setae longer dorsally. Dorsal surface of tarsomeres with abundant yellowish-white pubescence not obscuring integument, and long, erect yellowish-brown setae interspersed.

Abdomen. Sides of ventrites with abundant whitish pubescence not obscuring integument, pubescence gradually, slightly sparser toward ventrite 5; remaining surface with a few short, decumbent yellowish-white setae, slightly more abundant on ventrite 5; with long, erect yellowish-brown setae close to area with abundant pubescence; apex of ventrite 5 slightly rounded.

Dimensions in mm. Total length, 9.5; prothoracic length, 2.75; anterior prothoracic width, 1.4; posterior prothoracic width, 1.35; maximum prothoracic width, 1.4; humeral width, 1.9; elytral length, 5.85.

Type material. Holotype male ( INPA-COL 002853 ) from BRAZIL, Amazonas: Manaus, ZF-2 , km 14 , 2°35’21”S 60°06’55”W, “ Malaise Grande, lado poente,” 8 m, 04–23.X.2017, J.A. Rafael leg. ( INPA). GoogleMaps

Etymology. The specific epithet refers to the type locality, Brazil, Amazonas.

Remarks. Gnomidolon amazonicum sp. nov. is similar to Gnomidolon insigne Martins, 1967 , but differs as follows: central area of upper eye lobes with three rows of ommatidia; antennae mostly orangish; pronotum bicolorous; posterior half of elytra not entirely dark; and anterior half of elytra with black X-shaped macula. In G. insigne , the central area of the upper eye lobes has two rows of ommatidia, the antennae are brown or dark brown, the pronotum is entirely dark, the posterior half of elytra is entirely dark, and the anterior half of elytra has dark longitudinal area, reaching suture, scutellum, and the anterior margin. The new species is also similar to Gnomidolon biarcuatum (White, 1855) (see photographs on Bezark (2025) and in Martins (1962)), Gnomidolon bellus Martins & Galileo, 2002 (see photographs on Bezark (2025) and in Martins & Galileo (2002)), Gnomidolon humerale Bates, 1870 (see photographs on Bezark 2025), Gnomidolon peruvianum Martins, 1960 (see photographs on Bezark (2025) and in Martins (1967)), and Gnomidolon ubirajarai Joly, 1990 (see photographs on Bezark (2025) and in Joly (1990)) but differs especially by the elytral apex black (whitish in these five species).

Gnomidolon amazonicum can be included in the alternative of couplet “62” from Martins (2006) (translated, modified):

62(61). Posterior third of elytra tricolorous, orangish brown, reddish brown, and black apically. Brazil (Amazonas)................................................................................................ G. amazonicum sp. nov.

– Posterior third of elytra entirely light or dark, or light apically and preceded by a transverse brown band...............62’

62’(62) Apical yellowish macula obliquely prolonged forward close to the suture. Peru, Bolivia, Brazil (Acre, Maranhão, Mato Grosso, Mato Grosso do Sul, Goiás, Minas Gerais, São Paulo, Paraná, and Santa Catarina), and Paraguay.................................................................................................. G. pallidicauda Gounelle, 1909

– Apical yellowish macula restricted to the posterior quarter. Bolivia, Brazil (Paraíba, Bahia, Mato Grosso, Goiás, Mato Grosso do Sul, Minas Gerais, Espírito Santo, Rio de Janeiro, São Paulo, Paraná, Santa Catarina, and Rio Grande do Sul), Paraguay, Argentina, and Uruguay............................................................ G. varians Gounelle, 1909

Note: According to the alternative of couplet “5” from Martins (2006) (translated):

“5(2). Eytral apex with light area perpendicular to the suture; species that only have whitish apical spines or an apical spot whose anterior edge is oblique in relation to the suture are not considered here.......................................... 6 – Elytral apex concolorous with the apical half, without light band.............................................. 32”

As the new species has the elytral apex not concolorous with the apical half and some species has concolorous area shorter than the posterior half of elytra, it is needed to change the second option as follows: Elytral apex concolorous with the apical third or half, without light band, or dark and not concolorous with remaining apical half 32