Onalcidion maculatum, Vlasak & Santos-Silva, 2021

Vlasak, Josef & Santos-Silva, Antonio, 2021, Description of five new species of American Acanthocinini (Coleoptera, Cerambycidae, Lamiinae), Zootaxa 5061 (3), pp. 476-492 : 477-478

Onalcidion maculatum sp. nov.

( Figs 1–6 )

Description. Holotype male ( Figs 1–4 ). Head capsule dark brown, almost black, except ventral surface dark reddish brown; base of postclypeus and anteclypeus, and ventral mouthparts reddish brown; mandibles mostly reddish brown on basal half, black on apical half; scape brownish on basal third, dark brown on remaining surface; pedicel dark orangish brown basally, dark brown on remaining surface; antennomere III dark orangish brown on basal quarter, black on remaining surface; antennomere IV pale yellow about basal third, black on remaining surface; antennomere V dark orangish brown on basal fifth, black on remaining surface; antennomere VI orangish brown on basal quarter, black on remaining surface; remaining antennomeres dark brown, almost black. Pronotum dark brown, except blackish large macula on each side of anterior half. Sides of prothorax dark brown. Prosternum dark brown on anterior margin, reddish brown on remaining surface. Ventral surface of meso- and metathorax reddish brown, lighter on metaventrite. Scutellum and elytra dark brown, except black macula on area of centrobasal crest. Procoxae mostly yellow; mesocoxae yellowish with brownish areas interspersed; metacoxae brownish. Femoral peduncle pale yellow; femoral club dark brown, except dark orangish brown apex of dorsal surface. Protibiae dark brown, almost black, except central orangish brown band on dorsal and lateral surfaces; meso- and metatibiae dark brown, almost black on basal quarter and posterior half, pale yellow on remaining surface. Protarsomeres I–II dark brown, almost black; protarsomeres III brown basally and laterally, orangish brown on remaining surface; protarsomeres IV–V and claws orangish brown. Meso- and metatarsomeres I pale yellow on basal 2/3, almost black on distal third; meso- and metatarsomeres II almost black; meso- and metatarsomeres III dark orangish brown; meso-and metatarsomeres IV–V and claws orangish brown. Ventrite 1 orangish brown; ventrites 2-4 orangish brown with sides brown (dark area more distinct and darker toward ventrite 4); ventrite 5 dark brown.

Head. Frons minutely, abundantly punctate; with yellowish-brown pubescence partially obscuring integument, except dark brown pubescence with yellowish brown setae interspersed on central area close to antennal tubercles; with one long, erect dark seta on each side close to eyes. Area between antennal tubercles with brownish pubescence almost obscuring integument, and abundant yellowish-brown setae interspersed, except glabrous central area. Vertex and area behind upper eye lobes with dense yellow pubescence, except oblique brownish pubescent band on each side of central area between upper eye lobes, and sparser pubescence on vertex close to prothorax; with a few long, erect yellowish setae close to eyes. Area behind lower eye lobes with dense yellow pubescence close to eye, pubescence gradually paler toward ventral surface, mostly glabrous close to prothorax. Genae with pale yellow pubescence not obscuring integument, except glabrous apex, and a few long, erect yellowish setae interspersed. Wide central area of postclypeus with yellowish-brown pubescence not obscuring integument, and long, erect setae of same color interspersed. Sides of postclypeus glabrous. Labrum with yellowish pubescence not obscuring integument, almost absent toward anterior margin, and long, erect setae interspersed on posterior half (setae brown basally, gradually yellowish toward apex). Gulamentum smooth, glabrous, except anterocentral area depressed with yellowish pubescence not obscuring integument. Distance between upper eye lobes 0.24 times distance between outer margins of eyes; in frontal view, distance between lower eye lobes 0.51 times distance between outer margins of eyes. Antennae 2.8 times elytral length, reaching elytral apex at apex of antennomere V. Scape with abundant yellowish-brown pubescence on basal third, more brownish and less conspicuous on remaining surface; ventral surface with long, erect black setae on posterior quarter. Pedicel and antennomeres III–XI with yellowish-white pubescence not obscuring integument (pubescence appearing to be darker on dark area due to the integument color); ventral surface of pedicel and antennomere III with a few long, erect black setae; antennomeres IV–IX with a few long, black erect setae on ventral apex; antennomere III sinuous on basal third. Antennal formula based on length of antennomere III: scape = 1.20; pedicel = 0.11; IV = 0.96; V = 0.85; VI = 0.76; VII = 0.69; VIII = 0.76; IX = 0.77; X = 0.73; XI = 0.69.

Thorax. Prothorax wider than long; sides gradually divergent from anterolateral angles to apex of lateral tubercle, convergent behind lateral tubercles, parallel-sided close to posterolateral angles; lateral tubercle placed about posterior quarter. Pronotum somewhat coarsely and sparsely punctate on anterior 3/4, coarsely, deeply punctate on posterior quarter; with arched, large yellow pubescent band centrally on basal half, brownish pubescence centrally between yellow band and anterior margin, Ψ(psi)-shaped yellowish pubescent band on center of posterior half, anteriorly fused with apex of yellow pubescent band, inverted yellowish pubescent band on center of lateral areas, fused with apex of yellow pubescent band, transverse yellowish-white pubescent band close to posterior margin, and oblique, irregular yellowish pubescent band from posterolateral angles to near Ψ-shaped band; central area between yellow pubescent band and Ψ-shaped band with dark brown pubescence (less conspicuous centrally); sides of anterior third with light yellowish-brown pubescence; area between arms of inverted V-shaped band with brownish, slightly conspicuous pubescence; sides of inferior arm of Ψ-shaped band with brownish pubescence. Sides of prothorax with abundant pale yellowish-brown pubescence partially obscuring integument. Prosternum with abundant yellowish pubescence not obscuring integument, except glabrous narrow area close to anterior margin. Prosternal process strongly narrowed centrally. Mesoventrite with yellowish pubescence not obscuring integument, denser laterally. Mesanepisternum, mesepimeron, metanepisternum with dense yellowish pubescence. Sides of metaventrite with dense yellowish pubescence and remaining surface with abundant yellowish pubescence partially obscuring integument. Scutellum with yellow pubescent band on sides of anterior half, dense yellowish pubescent band on close to remaining margin, and slightly conspicuous brownish pubescence on remaining surface. Elytra. Centrobasal crest well-marked, with thick, abundant, erect setae; apex strongly obliquely truncate; about basal third with yellowish-white pubescence and irregular, abundant areas with brownish, slightly conspicuous pubescence interspersed; remaining surface with wide whitish pubescence surrounding two areas with brownish, slightly conspicuous pubescence (whitish pubescent band with rounded brownish pubescent maculae interspersed), anterior one distinctly larger, reaching sides, posterior one smaller, placed dorsally; apical area with longitudinal whitish pubescent band dorsally toward outer apical angle; with long, erect, sparse black setae throughout. Legs. Femora with abundant yellowish pubescence not obscuring integument, except brownish pubescence on dorsal surface of meso- and metafemoral clubs. Protibiae with yellowish pubescence not obscuring integument, less conspicuous, appearing to be dark on dorsal surface of posterior half due to the integument color, except posterior half of ventral half with bristly, dark yellowish-brown pubescence. Basal half of meso- and metatibiae with yellowish pubescence not obscuring integument, and posterior half with thick, short, erect, somewhat abundant black setae, except ventral apical area with dark yellowish-brown setae. Metatarsomeres I slightly longer than II–V together.

Abdomen. Ventrites with abundant yellowish pubescence not obscuring integument. Apex of ventrite 5 distinctly concave.

Female ( Figs 5–6 ). Similar to male. Differs by the antennae slightly shorter (2.6 times elytral length, reaching elytral apex at basal quarter of antennomere VI), antennomere III not sinuous basally, and apex of ventrite 5 truncate. Slightly more robust, elytra widest at middle, while in male elytra widest at humeri.

Chromatic variation. Ventral surface of thorax mostly brown; dark areas on ventrites 1–4 distinctly larger.

Dimensions (mm) (holotype male/ paratype males/ paratype females). Total length, 7.50/8.00–8.45/8.05– 9.25; prothoracic length, 1.45/1.65–1.75/1.50–1.55; anterior prothoracic width, 1.30/1.40–1.45/1.40–1.55; posterior prothoracic width, 1.55/1.60–1.75/1.60–1.85; maximum prothoracic width, 1.95/2.10–2.20/2.10–2.40; humeral width, 2.30/2.50–2.70/2.50–3.00; elytral length, 5.40/5.35–5.75/5.75–6.70.

Type material. Holotype male/ paratype female from COSTA RICA, Puntarenas: Santa Elena, Monteverde area , 29.VI.2017, J. Vlasak leg. ( MZSP). Additional paratypes (2 males, 2 females), same data as holotype ( JVCO).

Etymology. Latin, “maculatus” (stained, spotted); refers to the maculae on posterior half of the elytra.

Remarks. Onalcidion maculatum sp. nov. is similar to O. pictulum (White, 1855) ( Fig. 7 ), but differs as follows: body stouter; arched pubescent band of the pronotum reaching about middle; elytral pubescent pattern ( Figs 1, 5 ) different, especially on posterior 2/3, with well-defined maculae.

In O. pictulum , the body is slender, arched pubescent band of the pronotum almost reaching posterior margin, and the elytral pubescent pattern ( Fig. 7 ) is different, particularly in lacking the well-defined large macula on posterior half. The new species is also slightly similar to O. obscurum Gilmour, 1957 ( Fig. 8 ), but differs especially by the pronotal and elytral pubescent pattern. In O. obscurum , the pronotum lacks the contrasting areas of yellow and brown pubescence and the elytra does not contain the clearly delineated large macula on posterior half.

Monné & Martins (1976) reported O. pictulum from Costa Rica. Unfortunately, they did not provide a list of specimens examined. Monné (1990, 1995) reported only Colombia and Venezuela. Therefore, it is not possible to know if O. pictulum really occurs in Costa Rica, or if it was a misidentification of O. maculatum .

Figures

FIGURES 1–8. 1–4) Onalcidion maculatum sp. nov., holotype male: 1) Dorsal habitus; 2) Ventral habitus; 3) Lateral habitus; 4) Head, frontal view. 5–6) Onalcidion maculatum sp. nov., paratype female: 5) Dorsal habitus; 6) Ventral habitus. 7) Onalcidion pictulum (White, 1855), syntype, dorsal habitus (by Jesus Santiago Moure). 8) Onalcidion obscurum Gilmour, 1957, holotype male, dorsal habitus (by Jesus Santiago Moure).