Nyssodrysternum angulatum, Santos-Silva & Bezark & Tavakilian & Audureau, 2025

Nyssodrysternum angulatum sp. nov.

( Figs 8–13 View FIGURES 8–13 )

Description. Female holotype ( Figs 8–12 View FIGURES 8–13 ). Head capsule dark brown, slightly lighter on vertex, except reddish-brown area of genae close to frons and clypeus; ventral mouthparts brown except yellowish-brown apex of distal palpomeres and ligula; anteclypeus and labrum mostly dark yellowish brown; scape dark orangish brown, more reddish brown depending on light intensity, except dark-brown apical quarter; pedicel brown; antennomeres III–VI orangish brown except dark-brown apex, dark-brown area gradually wider toward VI; antennomeres VII–X dark brown (missing antennomere XI). Prothorax and ventral area of meso- and metathorax dark brown, except reddish-brown apex of prosternal process and area of metaventrite close to metacoxal cavities. Elytra mostly dark brown on anterior half, gradually light brown toward apex on posterior half. Femoral peduncles dark orangish brown, more reddish brown depending on light intensity, and femoral clubs dark brown. Tibiae and tarsi dark brown. Abdominal ventrites mostly dark brown, almost black on some areas, with irregular reddish-brown areas on sides of ventrites 1–4, margins of abdominal process, apex of ventrites 1–4, and apex of ventrite 5.

Head. Frons abundantly, very finely punctate; with abundant white pubescence not obscuring integument, except dense pubescence close to superior 3/4 of eyes, this pubescence reaching frontal area of antennal tubercles, and brown pubescence close to base of antennal tubercles. Vertex with dense, moderately wide yellow pubescent band centrally, from area between antennal tubercles to anterior margin of prothorax, except glabrous area of median groove between antennal tubercles; remaining surface of vertex and superior area behind upper eye lobes with abundant brown pubescence not obscuring integument. Remaining area behind upper eye lobes and area behind lower eye lobes with dense yellow pubescence. Genae 0.61 times the length of lower eye lobe; with abundant white pubescence not obscuring integument, except glabrous apex and almost glabrous area close to frons and clypeus; with one long, erect dark-brown seta interspersed on white pubescent area. Wide central area of postclypeus with abundant white pubescence not obscuring integument; with a few long, erect setae interspersed, setae dark brown, paler on apical region. Sides of postclypeus glabrous. Labrum with abundant white pubescence not obscuring integument on posterior half, glabrous on anterior half, except anterior margin with fringe of yellow setae; with long, erect, both dark brown and yellowish-white setae interspersed on pubescent area. Antennal tubercles mostly with brown pubescence not obscuring integument, pubescence whitish on posterior region. Gulamentum glabrous, except intermaxillary process with abundant whitish pubescence not obscuring integument. Distance between upper eye lobes 0.20 times distance between outer margins of eyes; in frontal view, distance between lower eye lobes 0.55 times distance between outer margins of eyes. Antennae (from base of scape to apex of antennomere X) 3.0 times elytral length, reaching elytral apex at apical third of antennomere V. Scape with narrow, distinct cicatrix on dorsal apex ( Fig. 9 View FIGURES 8–13 ); light integumental area with abundant whitish pubescence partially obscuring integument ventrally and basal third of inner surface, and remaining surface with abundant, shorter yellowish pubescence not obscuring integument; dark apical area with abundant yellowish pubescence not obscuring integument, pubescence appearing to be darker due to the integument color; with a few long, erect dark-brown setae near apex of ventral surface. Pedicel with abundant yellowish pubescence not obscuring integument, pubescence denser and yellower basally; with a few long, erect, thick blackish setae ventrally. Antennomere III with dense white pubescence basally, this pubescent area gradually wider toward ventral surface; remaining surface with abundant yellowish-white pubescence not obscuring integument on light integumental area, and abundant dark-brown pubescence with short, decumbent whitish setae interspersed on dark apical area; with a few short, erect, thick black setae interspersed throughout, setae more abundant ventrally. Antennomeres IV–VI with abundant yellowish-white pubescence not obscuring integument on light integumental area, and abundant dark-brown pubescence not obscuring integument, with short, decumbent whitish setae interspersed on dark apical area; with a few short, erect, thick black setae interspersed throughout. Antennomeres VII–X with abundant, both dark brown and whitish pubescence not obscuring integument; with a few short, erect yellowish-white setae interspersed throughout, and a few short, erect, thick black setae interspersed throughout on VII–VIII and only apically on IX–X. Antennal formula based on length of antennomere III: scape = 1.05; pedicel = 0.14; IV = 1.00; V = 0.94; VI = 0.88; VII = 0.86; VIII = 0.90; IX = 0.86; X = 0.88.

Thorax. Prothorax wider than long; anterior constriction well marked; sides divergent from anterior constriction to lateral tubercles, convergent from this point to posterolateral angles; lateral tubercles small, located on beginning of posterior fifth. Pronotum densely, minutely punctate, with transverse row of coarse punctures near posterior margin, punctures not following toward sides of prothorax, and a few coarse punctures interspersed laterally; with narrow, longitudinal white pubescent band centrally from anterior to posterior margin, partially absent on part of posterior third; with wide, longitudinal yellow pubescent band on sides, from anterior constriction to posterior sixth, pubescent bands widened from anterior to posterior region; sides of posterior sixth with dense, transverse yellowish-white pubescent band on each side; remaining surface with abundant brownish pubescence not obscuring integument, pubescence more dark yellowish-brown depending on light intensity, except glabrous anterior sulcus; with a few long, erect dark brown setae on sides of posterior fifth. Sides of prothorax with abundant brownish pubescence not obscuring integument close to pronotum, and abundant white pubescence not obscuring integument on remaining surface, except glabrous anterior sulcus. Ventral surface of thorax with abundant white pubescence not obscuring integument, pubescence distinctly denser laterally (we do not know if the pubescence was lost or partially lost in most of the central part of the metaventrite during the process of removing the specimen from the card to which it was glued, due to the fact that the glue used was not soluble in water or alcohol). Narrowest area of prosternal process 0.35 times procoxal width. Narrowest area of mesoventral process 0.92 times mesocoxal width; apex of mesoventral process 1.05 times mesocoxal width. Scutellum with narrow, longitudinal whitish pubescent band centrally and abundant yellowish pubescence not obscuring integument on remaining surface. Elytra. Moderately sparsely coarsely punctate on anterior third, coarse punctures absent on remaining surface; dorsal surface with longitudinal, oblique, wide yellow pubescent band, pubescence pale yellow from its basal third, arched on its basal region, with abundant white pubescence interspersed from its basal third to posterior quarter, margined with narrow white pubescent band on outer side of its anterior third and inner side of its posterior 2/3, widened on its central region and distinctly narrowed toward its apex; base with abundant whitish pubescence not obscuring integument between scutellum and longitudinal yellow pubescent band; with longitudinal white pubescent band laterally, from base to before middle of elytra, this pubescent area covering entire basal sixth, arched basally toward dorsal yellow pubescent band but not covering humerus; with wide, slightly oblique pale-yellow pubescent band with abundant white pubescence interspersed fusing apex of lateral white pubescent band to area near apex of dorsal yellow pubescent band; epipleural margin with abundant white pubescence partially obscuring integument; with triangular white pubescent macula laterally about middle, fusing epipleural and oblique yellow pubescent band on middle of dorsal surface; with narrow, longitudinal white pubescent band close to suture, from scutellum to about middle; posterior with dense pale-yellow pubescence, white close to suture, apex, and epipleural margin, except inclined, inverted V-shaped brownish pubescent macula dorsally, together forming M-shaped macula; remaining surface with abundant brownish pubescence not obscuring integument, pubescence more dark yellowish brown depending on light intensity. Legs. Femora with abundant grayish-white pubescence not obscuring integument. Tibiae with dense white pubescence, except: inner basal half of protibiae with sparser white pubescence; most of apical quarter of dorsal and lateral surfaces of protibiae with moderately abundant dark pubescence not obscuring integument; apical 2/3 of ventral surface of protibiae with dense, bristly dark yellowish-brown pubescence, appearing to be darker depending on light source; ventral surface of mesotibiae with abundant dark yellowish-brown pubescence not obscuring integument on basal 2/3, denser, bristly on apical third; apical third of dorsal and lateral surfaces of mesotibiae mostly with dark-brown pubescence, bristly ventrally; ventral surface, outer surface, and apical half of dorsal and inner surfaces of metatibiae with abundant dark pubescence not obscuring integument, pubescence more yellowish-brown depending on light source, bristly on apical fifth of ventral surface; mesotibiae with abundant, thick, erect dark setae on apical third of dorsal surface, and sparse, moderately thick, erect dark setae on apical 2/3 of ventral surface; metatibiae with sparse, short, erect dark setae on apical 2/3 of ventral surface and apical half of dorsal and lateral surfaces. Dorsal surface of tarsi mostly with dark pubescence not obscuring integument; metatarsomere I distinctly longer than II–III together.

Abdomen. Distinctly surpassing elytral apex; ventrites 1–4 with dense white pubescence laterally, abundant, not obscuring integument centrally, and sparse between these two areas, except glabrous central apex (we do not know if the pubescence was lost or partially lost in most of the central part of the metaventrite during the process of removing the specimen from the card to which it was glued, due to the fact that the glue used was not soluble in water or alcohol); ventrite 5 with dense white pubescence on sides of basal third, pubescence slightly sparser on remaining surface, especially centrally from middle; apex of ventrite 5 slightly concave, with long dark setae directed forward; last tergite triangular.

Male ( Fig. 13 View FIGURES 8–13 ). Similar to females, differing especially by femoral clubs distinctly stouter, especially in meso- and metafemora, and by the abdomen not surpassing elytral apex.

Variation. Head capsule, prothorax, ventral surface of meso- and metathorax, and elytra entirely dark brown; basal area of antennomeres III–VI dark reddish brown; yellow pubescent band on dorsal surface of anterior half sinuous; transverse and oblique yellow pubescent band about middle of elytra strongly widened; elytral suture with whitish pubescence from base to apex.

Dimensions (mm) (female holotype). Total length, 6.70; prothoracic length, 1.10; anterior prothoracic width, 1.25; posterior prothoracic width, 1.40; maximum prothoracic width, 1.65; humeral width, 1.95; elytral length, 4.30.

Type specimens. Female holotype from FRENCH GUIANA: Crique Blanche, ex larva, 12.VI.2011, J.L. Giuglaris leg. ( CASC, formerly LGBC). Paratypes . 04/ IV/2007, 1 male, piste Bélizon ex larva, J.L. Giuglaris collector ( LGBC) , 14 /III/2007, 2 males Route de Kaw ( JLGC) , 04/ IV/2007, 1 male, piste Bélizon ex larva ( JLGC) , 12/IV/2007, 1 female, piste Bélizon ex larva ( JLGC) , 01/VI/2009, 1 female, RN2 pk 125 ex larva ( JLGC) , 12/ VI/2011, 1 male Crique Blanche ex larva ( JLGC) ( Fig 23 View FIGURES 19–24 ) , 06/VII/2011, 1 male, 1 female, Crique Blanche ex larva ( JLGC) .

Note: There was also another specimen that had been sent for identification by the late Miguel A. Monné. That specimen was destroyed during the fire that devastated the “Palácio de São Cristóvão ” ( MNRJ). The data of this specimen were: Sinnamary ( Carbet Tava), 87 m, 05°01’04”N 53°01’53”W, by beating vegetation, 03.XI.93, 1 specimen, F. T. Hovore leg. ( MNHN). This specimen is not part of the type series GoogleMaps .

Etymology. The species name “ angulatum ” (Latin, meaning angular), refers to the angulate M-shaped dark macula on the elytra.

Remarks. According to Gilmour (1960) Nyssodrysternum has “a distinct, narrow apical cicatrix.” However, currently, Nyssodrysternum includes species with ( e.g. N. fasciatum Gilmour, 1960 ), sometimes very narrow, almost absent ( e.g. N. serpentinum (Erichson, 1847)) , or without ( e.g. N. amparense (Melzer, 1934)) an apical cicatrix on the scape. This suggests that it includes species belonging to at least two genera, or that the feature is extremely variable in the genus.

Nyssodrysternum angulatum sp. nov. is similar to N. freyorum (Gilmour, 1963) (see photograph on Bezark (2025) and in Gilmour (1963a)) but differs as follows: light elytral pubescence on basal half forming a subrectangular macula with its inner apex projected backward; and elytra with M-shaped dark macula dorsally on posterior third. In N. freyorum , the light elytral pubescence on the basal half does not form a subrectangular macula and posterior third of elytra without M-shaped dark macula dorsally.