Poeciloxestia nitida, Haller & Santos-Silva, 2023

Haller, Pierre & Santos-Silva, Antonio, 2023, Description of a new species of Poeciloxestia Lane from Venezuela (Coleoptera, Cerambycidae), Zootaxa 5278 (2), pp. 363-368 : 363-367

Poeciloxestia nitida sp. nov.

( Figs 1–5 )

Description. Holotype female. Integument mostly blackish; ventral mouthparts brown, except some palpomeres partially dark brown; elytra brownish orange, except: wide, longitudinal blackish band close to suture, considering both elytra subtriangular-shaped, from base to before middle, distinctly narrow centrally but gradually widened toward posterior third, then gradually narrowed toward sutural angle; sides with wide, longitudinal blackish band on anterior quarter, this band fused with the dorsal band on frontal area of humerus; somewhat narrow, longitudinal blackish band close to epipleural margin, from anterior third to apex, this band fused with sutural and on apex; epipleural margin entirely blackish. Apex of ventrites 2–4 brownish, especially 3 and 4.

Head. Frons without frontal plate; frontolateral depression distinct, irregular, coarsely, sparsely punctate; widely, deeply longitudinal sulcate centrally, sulcus distinctly narrower and shallower close to postclypeus; sides of central sulcus coarsely, confluently punctate, except entirely smooth anterior region; area close to eyes finely punctate, except smooth area close to postclypeus; sides of area close to postclypeus transversely depressed, almost smooth; punctate areas with short, bristly yellowish-brown setae, slightly more abundant close to eyes. Antennal tubercles elevated, finely, sparsely punctate, except smooth apex; with sparse, short, bristly yellowish-white setae on punctate region. Area between antennal tubercles widely, moderately deeply depressed, glabrous, smooth centrally, with coarse, anastomosed punctures laterally. Remaining surface of vertex very coarsely, irregularly vermiculate-punctate, except anastomosed punctures close to eyes; with a few short, bristly yellowish-white setae, except somewhat long and abundant, erect brownish setae close to eyes. Area behind upper eye lobes coarsely, densely punctate, except anastomosed punctures close to eye toward vertex, and smooth area close to eye toward lower eye lobe; with a few short, bristly yellowish-white setae on punctate area, except somewhat abundant and long, erect brownish setae on punctate area close to eye. Area behind lower eye lobes smooth superiorly close to eye, finely punctate inferiorly close to eye, obliquely striate on remaining surface, striae somewhat rugose superiorly; punctate area close to eye with both, short and whitish, and long and brownish setae; striate area glabrous. Genae sparsely, somewhat finely punctate, with sparse, somewhat short yellowish-white setae; genal pit well marked, not close to eye. Wide central area of postclypeus coarsely, confluently punctate, punctures finer and more isolated close to anteclypeus; area close to frons with sparse, erect yellowish setae, almost absent centrally, and one long, erect yellowish-brown seta on each side; area close to anteclypeus with moderately sparse and long, erect yellowish setae. Sides of postclypeus smooth, not considering microsculpture, glabrous. Labrum subcoplanar with anteclypeus at posterior half, inclined at anterior half; somewhat finely punctate, except smooth sides, area close to anteclypeus, and entire central region of posterior half; punctate area on posterior half with long, erect yellowish-brown setae, setae longer laterally; anterior half with abundant, bristly yellowish-brown setae. Gulamentum semi-circularly vermiculate and glabrous posteriorly; area between eyes slightly depressed, coarsely, confluently punctate, with long, erect yellowish-brown setae, longer and more abundant on intermaxillary process, and a few short whitish setae interspersed. Distance between upper eye lobes 0.31 times distance between outer margins of eyes; in frontal view, distance between lower eye lobes 0.48 times distance between outer margins of eyes. Antennae 1.35 times elytral length, reaching elytral apex near apex of antennomere XI. Scape longitudinally, widely sulcate on outer surface; somewhat sparsely, finely punctate dorsally and on inner surface, except smooth apex of dorsal surface and apical half of inner surface; densely, somewhat rugose-punctate on outer surface, except smooth apex and sparsely, finely punctate sulcus; ventral surface somewhat abundantly, finely punctate, except smooth apex; nearly all punctures on dorsal and lateral surfaces with short white seta; ventral surface with moderately long, decumbent yellowish-brown setae. Pedicel somewhat abundantly, finely punctate, except smooth apex; dorsal and lateral punctures with short white setae; ventral surface with sparse, subdecumbent yellowish setae. Antennomere III sparsely, finely punctate, punctures more abundant on some areas, absent on others; nearly all punctures on dorsal and lateral surfaces with short white setae; ventral surface with somewhat abundant, erect yellowish-brown setae; dorsal surface with a few long, erect yellowish-brown setae close to smooth apical area. Antennomere IV abundantly, finely punctate except smooth apex and subsmooth base, punctures denser dorsally close to smooth area, sparser ventrally; dorsal and lateral surface with abundant white pubescence not obscuring integument; ventral surface with somewhat abundant, long, erect yellowish-brown setae; dorsal and lateral surfaces with a few long, erect yellowish-brown setae close to apical smooth area. Antennomeres V–XI densely, minutely punctate, except smooth apex of V–X; with abundant yellowish pubescence, pubescence partially obscuring integument from IX; ventral surface with long, erect yellowish-brown setae, gradually shorter and sparser toward XI; dorsal and lateral surface of V–X with a few long, erect yellowish-brown setae close to smooth apical area; dorsal surface of V longitudinally, widely, shallowly sulcate on posterior half, sulcus not reaching smooth apical area; dorsal surface of VI–X longitudinally, widely, shallowly sulcate from base to smooth apical area, sulcus gradually shallower toward X; XI slightly constricted on base of apical third, with rounded apex. Antennal formula based on length of antennomere III: scape = 0.67; pedicel = 0.20; IV = 0.69; V = 0.77; VI = 0.71; VII = 0.71; VIII = 0.65; IX = 0.69; X = 0.67; XI = 0.85.

Thorax. Prothorax wider than long; anterior constriction well marked; sides rounded from anterior constriction to near posterior seventh, with four large, rounded protuberances, anterior one smaller, then divergent to posterolateral angles. Pronotum ( Fig 5 ) with one slightly elevated gibbosity on each side of anterior third; central region with somewhat cross-shaped smooth area, from anterior sixth to posterior quarter, with a few coarse punctures medially; anterocentral region with sparse, somewhat coarse punctures; posterior seventh with both coarse and fine punctures, except sides with abundant, somewhat fine punctures; area close to smooth central area, from middle to posterior seventh, sparsely, coarsely punctate; sides densely, coarsely scabrous-punctate; some punctures on wide central region with short white seta and some on posterior half with long, erect yellowish-white seta; rugose-punctate region with somewhat abundant, long, erect yellowish-white setae between anterior third and posterior seventh. Sides of prothorax coarsely scabrous-punctate; anterior region abruptly inclined toward anterior constriction; with sparse, long, erect light yellowish-brown setae. Prosternum abundantly rugose-punctate laterally, somewhat finely rugose-punctate centrally close to anterior constriction, rugose on transverse anterior sulcus, coarsely rugose on remaining central region; with a few, both short and somewhat long, yellowish setae, except abundant pale yellow pubescence close to procoxal cavities, pubescence gradually denser toward prosternal process. Prosternal process centrally carinate on basal half; sides slightly elevated, especially close to base of inclined posterior region; basal half with dense pale-yellow pubescence between carina and margins, with a few long, erect yellowish setae interspersed, glabrous on remaining surface; inclined area with abundant yellowish pubescence not obscuring integument; narrowest area 0.28 times procoxal width. Mesoventrite with slightly elevated, triangular shaped protuberance anterocentrally; with abundant yellowish pubescence not obscuring integument, except glabrous central region and apex of sides. Mesanepisternum and mesepimeron with abundant yellowish pubescence not obscuring integument. Mesoventral process longitudinally depressed centrally; sides of posterior half rounded widened; apex distinctly emarginate centrally; with abundant white pubescence not obscuring integument on sides of anterior 4/5, white pubescence not reaching margins posteriorly, and abundant pale-yellow pubescence not obscuring integument centrally, except glabrous anterocentral region; remaining apical region glabrous; narrowest area 0.6 times mesocoxal width. Metanepisternum with abundant yellowish-white pubescence not obscuring integument. Sides of metaventrite with dense yellowish-white pubescence anteriorly, pubescence gradually denser and yellower toward apex; remaining surface with sparse, short, decumbent white setae, with long, erect yellowish-brown setae interspersed, except glabrous posterior 2/3 of central region, and glabrous posterior third close to dense lateral pubescence. Scutellum with abundant pale-yellow pubescence not obscuring integument, except glabrous anterocentral region. Elytra. Somewhat abundantly, finely punctate on anterior 2/3, punctures sparser and finer on posterior third; dark dorsal surface somewhat finely rugose; sutural angle with short spiniform projection; sutural region with sparse, minute yellowish-white setae; epipleural margin with sparse, short yellowish setae on posterior half. Legs. Coxae with abundant pale-yellow pubescence not obscuring integument. Trochanters without modifications; with abundant white pubescence and long, erect yellowish-brown setae interspersed on surface coplanar with ventral surface of femora, almost glabrous on remaining surface. Femora sparsely, finely punctate, punctures absent on some regions; with sparse, short, decumbent whitish setae, absent on posterior half of ventral surface, except middle of dorsal surface of metafemora with dense, bristly yellowish-brown pubescence; basal half of ventral surface with long, erect yellowish-brown setae interspersed. Tibiae with somewhat abundant, both erect and suberect yellowish setae dorsally and laterally, long setae almost absent dorsally on meso- and metatibiae; posterior half of ventral surface with dense, bristly yellowish-brown setae, denser on protibiae. Dorsal surface of tarsi with abundant yellowish pubescence.

Abdomen. Ventrites with dense yellowish pubescence laterally; remaining surface with sparse, minute, decumbent whitish setae, except glabrous apex of 1–4; posterior third with long, erect yellowish-brown setae interspersed, absent centrally. Apex of ventrite 5 rounded.

Male ( Figs 6–7 ). Similar to female, differing mainly by the antennae 2.2 times longer than elytra, reaching elytral apex at posterior quarter of antennomere VIII.

Variation. Scutellum with dense grayish-white pubescence; sutural black macula weakly ( Fig. 8 ) or distinctly dentate ( Fig. 9 ) on apex of anterior triangular region.

Dimensions (mm) (Holotype female/ allotype male/ paratypes female). Total length, 24.30/22.00/29.00–26.30; prothoracic length, 3.50/3.80/4.70–4.00; anterior prothoracic width, 3.30/3.50/4.10–3.80; posterior prothoracic width, 3.90/4.10/5.50–4.60; maximum prothoracic width, 4.70/4.90/6.25–5.40; humeral width, 6.25/6.10/8.50– 7.00; elytral length, 16.80/16.00/21.80–18.10.

Type material. Holotype female from VENEZUELA, Carabobo: Pata Nemo , 100 m, V.2022, local collector ( MZSP, formerly PHCO) . Allotype male, 2 paratypes female, same data as holotype ( PHCO).

Etymology. Latin, “nitidus” (polished); allusive to the predominantly smooth central area of the pronotum.

Remarks. In the key provided by Fragoso (1978), the feature used in the alternative of couplet “5” (prothoracic profile bulged or not behind anterior constriction) is difficult to interpret because some species do not fit perfectly into any of the options. Therefore, in order to ascertain the placement of Poeciloxestia nitida sp. nov. in the key, we followed the two options. Considering the prothoracic profile bulged behind the anterior constriction, the key leads to the alternative of couplet “8,” with P. bivittata (Buquet, 1852) and P. suturalis (Perty, 1832) . Poeciloxestia nitida sp. nov. differs from P. bivittata especially by the dorsal black band on the elytra distinctly narrowed centrally (slightly sinuous form base to near apex in P. bivittata ), elytra without continuous, wide dark band close to epipleural margin, from base to apex (present in P. bivittata ). The new species differs from P. suturalis by the pronotum with the central area smooth with a few coarse punctures (densely and coarsely rugose-punctate in P. suturalis ), and the dorsal and lateral dark bands of the elytra as pointed above (in P. suturalis , the dark bands are as in P. bivittata ). Considering the prothoracic profile not bulged behind the anterior constriction, the key leads to alternative of couplet “13” and then, to alternative of couplet “14,” with P. melzeri Lane, 1965 and P. carlyslei Fragoso, 1978 , although the dark area on the base of the elytra does not completely surround the humerus. Poeciloxestia nitida sp. nov. differs from both P. melzeri and P. carlyslei by the pronotum with broad smooth central area (entirely rugose-punctate in P. melzeri and P. carlyslei , except a small smooth central area in P. melzeri ), posterior region of the sutural dark band on the elytra not abruptly widened or dentate (abruptly widened or dentate in P. melzeri and P. carlyslei ), and lateral dark band on the elytra interrupted before middle, except for the epipleural margin (lateral dark band entirely from humerus to apex in P. melzeri and P. carlyslei ).

Using the key provided by Martins & Monné (2005), P. nitida sp. nov. fits into the alternative of couplet “11” with P. paraensis Lane, 1965 and P. coriacea Martins & Monné, 2005 . The new species differs from both species mainly by the sculpturing of the pronotum (rugose-punctate in P. paraensis and P. coriacea ), and the dark central band on the elytra reaching humerus dorsally (not reaching in P. paraensis and P. coriacea ).

Figures

FIGURES 1–5. Poeciloxestia nitida sp. nov., holotype female: 1) Dorsal habitus; 2) Ventral habitus; 3) Lateral habitus; 4) Head, frontal view; 5) Pronotum.

FIGURES 6–9. Poeciloxestia nitida sp. nov. 6–7) Allotype male: 6) Dorsal habitus; 7) Lateral habitus. 8–9) Paratypes female, dorsal habitus: 8) Specimen 1; 9) Specimen 2.