Nealcidion apunctatum, Vlasak & Santos-Silva, 2024

Vlasak, Josef & Santos-Silva, Antonio, 2024, Ecuadorian Acanthocinini: description of two new species and transference and notes on Sympagus cooperi Monné & Monné, Zootaxa 5397 (1), pp. 80-90 : 81-84

Nealcidion apunctatum sp. nov.

( Figs 1–8 )

Description. Holotype male ( Figs 1–5 ). Integument mostly dark brown; scape brown basally, gradually light brown toward apex; pedicel light brown on basal half, brown on apical half; antennomeres III–VI with reddish-brown ring basally and on base of apical third, dark brown apically, brown on remaining surface; antennomere VII with narrow reddish-brown ring basally, wide reddish-brown ring centrally, brown on remaining surface; antennomeres VIII–XI with narrow reddish-brown ring basally, light brown on apical region, this area shorter on X–XI, orangish on remaining surface; ventral mouthparts reddish brown, except palpomeres mostly dark brown with yellowish-brown apex; anteclypeus and apical half of labrum yellowish brown. Pronotum with light brown macula on center of anterior half. Elytra blackish on some areas. Tibiae with narrow reddish-brown ring basally, wide orangish ring about middle, brown on remaining surface. Protarsomeres I–III mostly dark brown; IV and basal 3/4 of V reddish brown and apex of V dark brown. Meso- and metatarsomeres reddish brown, except dark brown apex of I, II, and V. Ventral surface of abdominal ventrites light brown with irregular dark-brown areas.

Head. Frons abundantly, minutely punctate; with abundant pale-yellow pubescence not obscuring integument, pubescence slightly brownish to yellowish white on some areas, except glabrous median groove; with one long, erect dark-brown seta close to eyes. Vertex with abundant pale-yellow pubescence, denser and yellower close to eyes, except dark-brown pubescent macula on each side of middle close to prothorax, and glabrous median groove, glabrous area distinctly widened between antennal tubercles and upper eye lobes; with a few long, erect yellow setae close to eyes. Area behind upper eye lobes with dense yellow pubescence. Area behind lower eye lobes with dense yellow pubescence close to eyes, pubescent area widened centrally, glabrous close to prothorax. Genae finely, transversely, shallowly striate-punctate, except smooth apex; with sparse pale-yellow pubescence, slightly more abundant close to eyes, except glabrous smooth area; with a few long, erect brownish setae interspersed. Antennal tubercles with abundant pale-yellow pubescence not obscuring integument, yellower and denser apically. Wide central area of postclypeus with sparse, bristly pale-yellow setae; with one long, erect seta on each side, setae dark brown basally, yellowish white on their remaining surface. Labrum with abundant yellowish-white pubescence on posterior third, yellowish-brown centrally, glabrous on anterior third, except anterior margin with fringe of golden setae; central area with long, erect setae, setae dark brown basally, yellowish white on remaining surface. Gulamentum smooth, glabrous, except intermaxillary process with a few erect, both short and long brownish setae. Distance between upper eye lobes 0.21 times distance between outer margins of eyes; in frontal view, distance between lower eye lobes 0.54 times distance between outer margins of eyes. Antennae 2.6 times elytral length, reaching elytral apex at base of antennomere VI. Scape gradually widened from base to apical quarter, then more abruptly widened ventrally, and narrowed from this point toward apex; with abundant pale-yellow pubescence not obscuring integument; with long, erect pale-yellow setae ventrally. Pedicel with abundant pale-yellow pubescence on basal half and abundant brown pubescence on apical half; with one long, erect pale-yellow seta ventrally. Antennomeres III–VI with dense yellowish-white pubescence on light rings, abundant dark-brown pubescence apically, and abundant brown pubescence not obscuring integument on remaining surface; with sparse, short, erect yellowish setae throughout; III–V with long, erect yellowish-brown setae ventrally; VI with one long, erect yellowish-brown setae on ventral apex. Antennomeres VII–XI with dense yellowish-white pubescence on orangish area, pubescence almost absent basally, and sparse yellowish-white pubescence on apical brown area; with short, erect yellowish-white setae throughout; apex of XI distinctly widened on inner surface. Antennal formula (ratio) based on length of antennomere III: scape = 0.91; pedicel = 0.08; IV = 0.85; V = 0.68; VI = 0.65; VII = 0.60; VIII = 0.61; IX = 0.63; X = 0.58; XI = 0.57.

Thorax. Prothorax wider than long; anterior constriction well marked; sides rounded, gradually widened from anterior constriction to posterior sixth, then slightly divergent toward posterolateral angles. Pronotum with elongated gibbosity on each side of center, from anterior sixth to posterior quarter, and another, less elevated gibbosity centrally from about middle to posterior fifth; sparsely, coarsely punctate near anterior margin; with arched row of coarse puncture near posterior margin, punctures distinctly coarser than anterior punctures, and sparser, coarse punctures on posterior third; remaining surface smooth; with dense blackish pubescence on lateral gibbosities, with pale-yellow pubescence centrally, this area wide on anterior third with pubescence abundant, not obscuring integument, narrow, forming dense pubescent band on posterior fifth, sparse, surrounding central gibbosity on remaining surface; central gibbosity and remaining central region on posterior third with sparse brown pubescence; sides with dense pale-yellow pubescence, slightly yellower, forming oblique band close to outer margin of lateral gibbosities, except large, longitudinal dark-brown pubescent band close to pale-yellow band, irregular dark-brown pubescent macula on each side of middle, rounded dark-brown pubescent spots on sides of anterior third, and glabrous spot on sides of posterior third; glabrous spots with one long, erect brown seta; remaining posterior third with a few long, erect brown setae. Sides of prothorax with dense pale-yellow pubescence with brown pubescent maculae interspersed. Prosternum with abundant yellowish-brown pubescence partially obscuring integument, except glabrous narrow area close to anterior margin. Prosternal process with sides convergent from base to posterior third, then distinctly widened; with abundant yellowish-brown pubescence partially obscuring integument except almost glabrous apex; narrowest area 0.28 times procoxal width. Ventral surface of meso- and metathorax with yellow pubescence, dense laterally, sparser centrally, especially on posterocentral 2/3 of metaventrite; mesoventral process longitudinally carinate centrally, not widened apically; apex slightly sinuous, 0.59 times mesocoxal width. Scutellum with yellowish-brown pubescence centrally, pubescence more abundant on anterior half, and blackish pubescence not obscuring integument laterally. Elytra. Sides convergent from humerus to near apex, then subparallel-sided; apex triangularly projected on outer angle, concave to slightly projected on sutural angle; centrobasal crest moderately elevated, with short, bristly black setae dorsally; with two distinct longitudinal carinae dorsally, innermost from centrobasal crest to apex of elytra, outermost from near humerus to near apex, almost fused apically with innermost; with another slightly distinct carina dorsally, from humerus to posterior quarter; humeral carina slightly distinct disappearing near apex; abundantly, coarsely punctate on anterior quarter and sides, lateral punctures gradually finer, sparser, not reaching apex; remaining surface very finely punctate, punctures mostly covered by pubescence; anterior quarter and sides with abundant, both pale-yellow and yellowish-brown pubescence, partially obscuring integument, not reaching apex, with dark-brown pubescent spots interspersed; posterior 3/4 of dorsal surface with dense pale-yellow pubescent band close to suture, obliquely projected forward on sides of its anterior region, slightly projected sideward on posterior third, and widened apically, covering entire apex, except oblique yellowish-brown pubescent band interspersed on its anterior quarter, somewhat brownish depending on light intensity, V-shaped considering both elytra, and yellow pubescent band close to suture, from V-shaped band to posterior third, with dark-brown pubescent spots interspersed; area between projections of pale-yellow pubescent band with longitudinal blackish pubescent band, anterior one larger; area between posterior blackish pubescent band and pale-yellow pubescent band with yellowish-brown pubescent macula. Legs. Femora with abundant yellowish pubescence partially obscuring integument, except transverse, brownish pubescent band dorsally and laterally after middle of femoral club. Protibiae slightly projected ventrally about middle, and distinctly widened apically on ventral surface; all tibiae with dense pale-yellow pubescent ring basally and about middle, and brownish pubescence not obscuring integument between pale-yellow pubescent rings; protibiae with brownish pubescence not obscuring integument dorsally and laterally close to central pale-yellow pubescent ring, abundant yellowish pubescence on apex of dorsal and lateral surfaces, and dense, bristly yellowish-brown pubescence on apical half of ventral surface; apical half of dorsal surface of mesotibiae with abundant, short, thick yellowish-brown setae, sides with yellowish pubescence not obscuring integument, with yellowish-brown setae interspersed, and ventral surface with bristly yellowish-brown pubescence; apical half of metatibiae with brownish pubescence close to dense pale-yellow pubescent ring and yellowish pubescence not obscuring integument apically, with suberect yellowish-brown setae interspersed. Dorsal surface of tarsomeres with abundant yellowish-white pubescence, except sparser and dark-brown pubescence on apex of tarsomeres I, II, and V; metatarsomere V about 1.5 times longer than II–III together.

Abdomen. Ventrites with abundant yellow pubescence not obscuring integument laterally, with irregular glabrous maculae interspersed, and sparser yellowish-white pubescence centrally, except glabrous apex of ventrites 2–4; apex of ventrite 5 strongly concave centrally, making sides spiniform ( Fig. 5 ).

Female ( Figs 6–8 ). Similar to males, differing by the shorter antennae, 2.1 times elytral length, reaching elytral apex at apical quarter of antennomere VI, abdominal ventrite 5 longer with apex truncate ( Fig. 6 ), and last tergite projected triangularly, distinctly surpassing ventrite 5.

Dimensions in mm (Holotype male/ paratype females). Total length, 9.65/9.15–10.50; prothoracic length, 1.60/1.45–1.65; anterior prothoracic width, 1.90/1.80–2.10; posterior prothoracic width, 2.30/2.15–2.50; maximum prothoracic width, 2.60/2.35–2.85; humeral width, 3.70/3.50–4.10; elytral length, 7.10/7.00–7.95.

Type material. Holotype male from ECUADOR, Napo: Cosanga , 2100 m, at light, 25.XI.2022, J. Vlasak leg. ( MZSP) . Paratypes – 3 females, same data as holotype ( JVCO) .

Etymology. The name “apunctatum ,” from Latin “punctatus” (punctated), with a prefix “a” (indicating a “lack of,” “absence of,” “not”) refers to the lack of coarse punctures along suture on posterior 3/4 of the elytra.

Remarks. Nealcidion apunctatum sp. nov. belongs to the group of species with distinct dorsal carina. It is similar to N. ghiae Santos-Silva, Nascimento, Botero & McClarin, 2021 (see photographs on Bezark 2023 a and Santos-Silva et al. 2021) but differs as follows: upper eye lobes wider than basal diameter of the scape; centrobasal crest of the elytra distinctly less elevated; and pubescence close to suture obscuring punctures on posterior 3/4 of the elytra. In N. ghiae , the upper eye lobes are about as wide as the basal diameter of the scape, centrobasal crest of the elytra is strongly elevated, and elytral pubescence is not obscuring punctures close to suture. Nealcidion apunctatum sp. nov. differs from N. lineatum (Bates, 1863) (see photographs on Bezark 2023 a and Santos-Silva et al. 2021) by the prosternal process distinct narrower (narrowest area about 0.5 times procoxal width in N. lineatum ), and pubescence close to suture obscuring punctures on posterior 3/4 of the elytra (not obscuring in N. lineatum ). Nealcidion apunctatum sp. nov. differs from N. sublineatum Vlasak & Santos-Silva, 2022 especially by the elytral apex not truncate and by the outer angle distinctly spiniform (elytral apex truncate and outer angle not spiniform in N. sublineatum ).

Figures

FIGURES 1–8. Nealcidion apunctatum sp. nov. 1–5) Holotype male: 1) Dorsal habitus; 2) Ventral habitus; 3) Lateral habitus; 4) Head, frontal view; 5) Abdominal ventrite 5. 6–8) Paratype female: 6) Abdominal ventrite 5; 7) Dorsal habitus; 8) Ventral habitus.