Pygmodeon incertum, Vlasak & Santos-Silva, 2025

Pygmodeon incertum sp. nov.

( Figs 36–39 View FIGURES 36–41 )

Description. Male holotype. Head capsule dark-brown behind upper eye lobes; light brown between antennal tubercles and anterior margin of upper eye lobes, darker centrally; brown behind lower eye lobes close to eye, dark-brown on remaining surface; brown on vertex from eyes to prothorax, darker centrally; reddish brown on frons, with irregular narrow dark-brown areas on inferior half, gradually orangish brown laterally toward vertex; orangish-brown on antennal tubercles; reddish-brown on genae, with irregular blackish area interspersed apically; reddish-brown on clypeus and labrum, darker on margins; dark orangish-brown ventrally, with irregular, both reddish-brown and dark-brown areas interspersed. Mentum dark orangish brown, except brownish anterior region; remaining surface of ventral mouth parts orangish brown, except palpi mostly yellowish brown. Mandibles reddish brown on basal 3/4, except blackish margins, mostly black on apical quarter. Scape orangish brown with irregular brownish areas apically; pedicel dark orangish brown with irregular dark-brown areas; antennomere III dark reddish brown basally, orangish brown on remaining basal half, reddish brown on apical half; antennomeres IV–X orangish brown basally, reddish brown on remaining surface, reddish-brown areas darker from VI; antennomere XI mostly orangish brown. Pronotum dark brown on wide central area, slightly darker laterally, orangish brown on anterior eighth, except brown anterior margin, dark orangish brown on posterior eighth, except brown posterior margin. Sides of prothorax dark reddish brown on wide central area, darker depending on light intensity, mostly orangish brown anteriorly and posteriorly. Prosternum brown on posterior 3/4, slightly lighter on anterior region of this area, except dark orangish-brown area close to procoxal cavities and prosternal process and dark-brown margins of procoxal cavities; orangish brown on anterior quarter, except brown anterior margin. Prosternal process dark orangish brown, more brownish on margins. Ventral surface of mesothorax brown, darker on some areas, except dark orangish-brown area of mesoventrite close to procoxal cavities and mesoventral process, both with dark margins. Ventral surface of metathorax mostly reddish brown, more orangish centrally, except dark-brown margins. Scutellum mostly dark orangish brown. Elytra yellowish-brown about anterior half, except brownish macula on anterior quarter close to suture and scutellum, light-brown on remaining area close to suture, and ascending oblique brown band dorsally, from near suture to near humerus, strongly, abruptly widened on sides of anterior third, then covering almost entire anterior quarter of epipleural region; remaining surface brown, except oblique yellowish-brown macula dorsally on posterior third and yellowish-brown lateral apex. Coxae, trochanters and femoral clubs mostly dark orangish brown; remaining surface of femora mostly light brown. Tibiae mostly light brown with irregular darker areas. Tarsi orangish brown. Abdominal ventrites mostly dark orangish brown with irregular brown areas centrally, larger on ventrites 1–3.

Head. Frons densely, coarsely punctate, punctures anastomosed on inferior half, confluent on superior half; with sparse yellowish pubescence, slightly more abundant on superior half. Antennal tubercles abundantly, coarsely punctate, except smooth apex; with moderately sparse yellowish pubescence, except glabrous apex. Vertex abundantly, coarsely, confluently punctate; with sparse yellowish pubescence, sparser close to prothorax, except abundant yellowish pubescence behind eyes; with a few long, erect yellowish-brown setae close to eyes. Area between antennal base and eyes with abundant yellowish-brown pubescence. Area behind upper eye lobes with sculpturing as on frons; with abundant yellowish pubescence close to eye, distinctly sparser toward prothorax. Area behind lower eye lobes sparsely, coarsely punctate close to eye, transversely striate-punctate close to prothorax; with sparse yellowish pubescence close to eye, glabrous on remaining surface; with a few long, erect yellowish-brown setae close to eye. Genae abundantly, coarsely punctate laterally, punctures sparser frontally; with abundant yellowish pubescence laterally, pubescence sparser frontally, except glabrous apex. Wide central area of postclypeus rugose close to frons, transversely carinate close to anteclypeus and sulcate close to carina; with sparse yellowish pubescence laterally, glabrous on remaining surface. Sides of postclypeus smooth, glabrous. Labrum mostly smooth and glabrous, with one tuft of long, erect yellowish-brown setae on each side. Gulamentum smooth, glabrous on posterior half; anterior half transversely striate-punctate with sparse, long, erect yellowish setae. Basal 2/3 of outer surface of mandibles abundantly, coarsely, confluently punctate, with sparser yellowish pubescence and long, erect yellowish-brown setae interspersed, apical third smooth, glabrous. Distance between upper eye lobes 0.33 times distance between outer margins of eyes; in frontal view, distance between lower eye lobes 0.45 times distance between outer margins of eyes. Antennae 1.8 times elytral length, reaching elytral apex near apex of antennomere IX. Antennomeres not carinate dorsally; III–VI distinctly tumid, VII–XI filiform; with abundant yellowish pubescence not obscuring integument, except glabrous dorsal apex of scape; scape, pedicel, and antennomeres III–IV with sparse, long, erect yellowish-brown setae throughout, setae more abundant ventrally; antennomeres V–VI with a few long, erect yellowish-brown setae ventrally and entire apex, and short, erect yellowish-brown setae interspersed throughout; antennomeres VII–X with short, erect yellowish setae interspersed throughout, and long, erect yellowish-brown setae on apex; antennomere XI with short, erect yellowish setae interspersed throughout. Antennal formula (ratio) based on length of antennomere III: scape = 0.74; pedicel = 0.18; IV = 0.78; V = 0.85; VI = 0.89; VII = 0.89; VIII = 0.85; IX = 0.81; X = 0.74; XI = 1.00.

Thorax. Prothorax longer than wide; anterior and posterior constrictions distinct; sides rounded between constrictions. Pronotum tumid between anterior third and posterior quarter, slightly gibbous centrally, from middle to posterior third; sparsely, coarsely punctate; with abundant yellowish-white pubescence not obscuring integument, except glabrous central gibbosity and anterior and posterior margins and sparse pubescence close to anterior margin; with a few long, erect yellowish-brown setae interspersed. Sides of prothorax sparsely, coarsely punctate, except sparsely, finely punctate anterior third and smooth area close to posterior margin; with abundant yellowish-white pubescence not obscuring integument, forming dense longitudinal band centrally close to prosternum, pubescence absent on anterior third and close to posterior margin, and long, erect yellowish-brown setae interspersed. Prosternum sparsely, coarsely punctate on posterior half, punctures slightly more abundant close to coxal cavities; anterior half transversely, finely, shallowly striate; posterior half with sparse yellowish-white pubescence and a few long, erect yellowish-brown setae interspersed; anterior half mostly glabrous. Prosternal process with moderately abundant yellowish-white pubescence,except glabrous margins;narrowest area0.1times procoxal width.Procoxal cavities open posteriorly. Mesoventrite with very sparse yellowish pubescence anterocentrally, pubescence moderately abundant, not obscuring integument on remaining surface. Mesanepisterna and mesepimera with abundant yellowish-white pubescence. Mesoventral process with abundant yellowish pubescence not obscuring integument; sides concave, distinctly widened apically; apex notched centrally; narrowest area 0.51 times mesocoxal width; apex 0.77 times mesocoxal width. Ventral surface of metathorax with abundant yellowish pubescence not obscuring integument, slightly sparser centrally on metaventrite. Scutellum with dense whitish pubescence. Elytra. Parallel-sided on anterior 3/4, then rounded toward apex; moderately sparsely, coarsely punctate; apex truncate, slightly projected on outer and sutural angles; most punctures with long, erect yellowish-brown setae. Legs. Coxae, trochanters, and femora with abundant yellowish-white pubescence not obscuring integument; trochanters and femora with long, erect yellowish-brown setae interspersed. Protibiae with abundant yellowish pubescence not obscuring integument, pubescence more yellowish white depending on light intensity, except denser, bristly yellowish-brown pubescence on apical half of inner and ventral surface of protibiae, pubescence lighter depending on light intensity, and abundant, bristly yellowish-brown pubescence on apical third of ventral surface of meso- and metatibiae; all tibiae with long, erect yellowish-brown setae interspersed. Dorsal surface of tarsomeres with moderately abundant light yellowish-brown pubescence, and long, erect setae of same color interspersed; metatarsomere V slightly longer than II–III together.

Abdomen. Ventrites with abundant yellowish pubescence not obscuring integument, except glabrous apex of ventrites 1–4; with long, erect yellowish-brown setae interspersed. Apex of ventrite 5 subtruncate.

Dimensions (mm). Total length, 8.50; prothoracic length, 1.55; anterior prothoracic width, 1.10; posterior prothoracic width, 1.15; maximum prothoracic width, 1.30; humeral width, 1.60; elytral length, 5.45.

Type specimen. Male holotype from ECUADOR, Loja: vicinity of Macará , 700 m, collected in the pupal stage, 20–24 Feb 2024, J. Vlasak leg. ( MZSP, formerly JVCO) .

Etymology. The name “ incertum ” (Latin, meaning uncertain) alludes to the difficulty of the generic placement of this species.

Remarks. The allocation of Pygmodeon incertum sp. nov. is problematic. Following the key to the tribes of Tropidini in Martins & Galileo (2007), it should be placed in Neoibidionina , since it has the procoxal cavities open posteriorly, a cylindrical scape that is slightly and gradually thickened toward the apex, antennomere IV shorter than III and V, and in males often thickened. In this tribe, the key to the genera in Martins & Galileo (2007) leads the new species to the genus Compsibidion Thomson, 1864 . However, the new species resembles some species of Pygmodeon Martins, 1970 , and Heterachthes Newman, 1840 . According to Martins (2009) on Pygmodeon (translated): “Strictly speaking, this genus should belong to Ibidionina [currently Neoibidionina ] because it has narrowly open procoxal cavities. Its placement in Compsina is justified by the flagellomeres and tibiae lacking carinae, and the lateral parts of the prothorax having a narrow band of pubescence at the boundary with the prosternum. These features are found only in Heterachthes , with which Pygmodeon is very similar.” These two genera were separated in the key to the genera of Compsina in Martins (2009) by the shape of the procoxal cavities: open posteriorly in Pygmodeon and closed in Heterachthes . Consequently, since the new species has the procoxal cavities open posteriorly, we rule out the possibility of including it in Heterachthes . Among the features mentioned to define Pygmodeon, Martins (2009) stated that the basal flagellomeres are imperceptibly thickened in males. However, they are distinctly thickened in the males of P. boreale Martins, 1971 ( Figs 40–41 View FIGURES 36–41 ). Furthermore, the opening of the procoxal cavities in the species currently included in Compsibidion is variable, being either narrow or wide, and there are species in this genus with a longitudinal band of pubescence on the sides of the prothorax along the prosternum. For example, C. paulista (Martins, 1962) and C. reichardti (Martins, 1962) have this pubescent band, less distinct in the latter and therefore, they should be transferred to Pygmodeon . However, both Pygmodeon and Compsibidion include species with very distinct features, which suggests they are polyphyletic. Therefore, we were unable to find a reliable feature that would allow the separation of Pygmodeon and Compsibidion , based on the features used by Martins & Galileo (2007) and Martins (2009). For now, we are using the presence of a pubescent band on the sides of the prothorax, close to the prosternum, as a provisional feature to distinguish these two genera.

Pygmodeon incertum differs from Pygmodeon boreale ( Figs 40–41 View FIGURES 36–41 ) as follows: frons not distinctly vermiculate; in frontal view, lower eye lobes about 3.0 times genal length; ommatidia coarser; prothorax distinctly longer than wide; pronotum sparsely punctate; different elytral color pattern; and elytra mostly parallel-sided. In P. boreale , the frons is distinctly vermiculate, in frontal view, lower eye lobes about 1.5 times the genal length, the ommatidia are slender, more distinctly when comparing the ommatidia of upper eye lobes, the prothorax is slightly longer than wide, the pronotum is abundantly punctate, and the elytra are not parallel-sided. The elytral color pattern distinguishes this species from all others in Pygmodeon . It differs from P. mutabile (Melzer, 1935) , especially by the upper eye lobes with four rows of ommatidia (three in the two males of P. mutabilis examined, four in the five females, a paratype of each sex) and by the elytral color pattern (although variable in P. mutabilis , the circum-scutellar area is always distinctly brown).

LAMIINAE Latreille, 1825

ACANTHOCININI Blanchard, 1845