Leptocometes brevicornis, Vlasak & Santos-Silva & Nascimento, 2020

Vlasak, Josef, Santos-Silva, Antonio & Nascimento, Francisco Eriberto De L., 2020, Two new species, transference, notes, and new record in South American Acanthocinini (Coleoptera, Cerambycidae, Lamiinae), Zootaxa 4779 (3), pp. 355-366 : 361-364

Leptocometes brevicornis sp. nov.

( Figs. 18–21 )

Description. Male. Integument mostly dark brown, almost black; scape dark reddish brown on basal third, darker toward apex; pedicel reddish brown basally, gradually darker posteriorly; antennomere III reddish basally, dark reddish brown on remaining anterior 4/5; antennomere IV reddish basally, gradually reddish brown toward apex of anterior 3/4; antennomere V reddish basally, reddish brown on remaining anterior third; antennomeres VI–XI reddish basally; mouthparts reddish brown, except black palpi (apex of last palpomeres somewhat reddish). Elytra with wide, irregular dark reddish-brown band dorsally, starting basally between humeri and scutellum, following obliquely toward suture, distinctly, widely notched just after middle, narrowed on its posterior area; some areas of elytra distinctly black; femoral peduncle pale yellow; tibiae with wide pale-yellow ring before middle; basal area of protarsomere I reddish brown; about basal half of mesotarsomere I and basal 2/3 of metatarsomere I pale yellow (more reddish depending on light intensity).

Head. Frons microscopically, abundantly punctate; with yellowish-white pubescence partially obscuring integument (yellower depending on light intensity), with brownish pubescence interspersed; with a few long, erect brown setae close to eyes. Area between antennal tubercles with yellowish-white pubescence centrally (yellower depending on light intensity), gradually brown toward antennal tubercles. Remaining surface of vertex with yellowish and yellowish-brown pubescence centrally between eyes, yellowish close to eyes, brown on remaining surface. Area behind upper eye lobes glabrous close to eye, with narrow yellowish-white pubescent band close to glabrous area, and brown pubescence close to prothorax. Area behind lower eye lobes with yellowish-brown pubescence partially obscuring integument, denser more pale yellow toward upper eye lobe; with long, erect brown setae close to eye. Genae slightly shorter than lower eye lobe; with golden pubescent band close to eye (more pale yellow depending on light intensity), and pale yellow, sparser pubescence on remaining surface, except glabrous, longitudinal band close to frons. Antennal tubercles mostly with brown pubescence obscuring integument, paleyellow pubescence frontally over lower eye lobe, and yellowish pubescence on apex. Postclypeus with sparse yellowish pubescence on wide central area, glabrous laterally; with long, erect black setae on wide central area. Area of anteclypeus close to postclypeus with long, erect yellowish setae centrally, more golden and abundant laterally. Labrum with long yellowish-white setae posteriorly, yellower anteriorly; with long, erect brown setae on transverse middle area. Median groove distinct from clypeus to near prothoracic margin. Distance between upper eye lobes 0.36 times length of scape (0.38 times distance between outer margins of eyes); in frontal view, distance between lower eye lobes 0.62 times length of scape (0.60 times distance between outer margins of eyes). Antennae 2.05 times elytral length, reaching elytral apex at basal third of antennomere VII. Scape with yellowish-white pubescence not obscuring integument on sides of basal 2/3 and basal half of ventral surface; remaining surface with minute, slightly distinct pubescence of same color; with a few long, erect black setae on apex of ventral surface. Pedicel with yellowish-white pubescence basally, more brownish on remaining surface; with long, erect black seta ventrally. Base of antennomeres III–XI with dense yellowish-white pubescence (whiter depending on light intensity), and minute, somewhat sparse yellowish-white pubescence on remaining surface; ventral surface of antennomeres III–IV with long, erect black setae (more abundant on III); ventral apex of antennomere V with long, erect black seta; ventral apex of antennomeres VI–VIII with short, erect black seta. Antennal formula (ratio) based on length of antennomere III: scape = 1.00; pedicel = 0.16; IV = 0.82; V = 0.65; VI = 0.57; VII = 0.52; VIII = 0.47; IX = 0.47; X = 0.46; XI = 0.41.

Thorax. Prothorax transverse; with large, conical tubercle placed slightly after middle. Pronotum with large, elevated tubercle with rounded apex on each side of anterior third, and slightly marked central gibbosity centrally on posterior half; with yellowish-white pubescence, denser laterally, sparser centrally, absent on top of central gibbosity, with white pubescent spots interspersed, except mostly blackish pubescence on anterior tubercles; with long, erect dark setae laterally on posterior third. Sides of prothorax with yellowish-white pubescence not obscuring integument (slightly yellower depending on light intensity). Prosternum with yellowish-white pubescence, denser laterally, sparser centrally, absent close to anterior margin and anterocentral area. Narrowest area of prosternal process 0.15 times width of procoxal cavity. Apex of mesoventral process 0.34 times width of mesocoxal cavity. Wide central area of mesoventrite with sparse yellowish-white pubescence, and sides with denser pubescence of same color. Mesanepisternum, mesepimeron, and metanepisternum with dense yellowish-brown pubescence. Metaventrite with yellowish-white pubescence partially obscuring integument. Scutellum with blackish pubescence on sides of anterior 2/3, dense yellowish-white pubescence on center of anterior 2/3, and yellowish-brown pubescence on posterior third. Elytra. Coarsely, abundantly punctate on anterior half, punctures gradually finer, sparser on posterior half. Dark reddish-brown area of elytra with yellowish-white pubescence, with white pubescent maculae interspersed (white pubescence occupying nearly all posterior area); circum-scutellar area with yellowish-white pubescence not obscuring integument, with white pubescence interspersed; sides and black dorsal areas with dark, nearly inconspicuous pubescence, with white pubescent spots interspersed (white spots absent on blackish dorsal areas projected toward suture on posterior half); posterior half with small, circular spots with inconspicuous pubescence (spots more distinct near suture); entire surface with long, erect, sparse dark setae. Centrobasal crest elevated, small, with dark erect setae on top; distal margin of elytra concave. Sutural margins dehiscent in posterior third.

Legs. Femora distinctly pedunculate-clavate; with yellowish-white pubescence, denser on some areas, sparser on other (whiter depending on light intensity). Protibiae slightly arched inward in posterior half; posterior third of ventral surface widely notched; with brown pubescence on dark areas, yellowish white on light central ring; posterior half with dark, short, erect setae, denser ventrally. Mesotibiae with yellowish-white pubescence basally, brown, slightly conspicuous pubescence on remaining anterior area, yellowish-white pubescence on light central ring, and dark, bristly, thick pubescence on posterior dark area. Metatibiae sinuous; pubescence as on mesotibiae, with sparse, long, erect dark setae interspersed on anterior half. Tarsi with sparse yellowish-white pubescence on lighter area, dark brown on darker areas.

Abdomen. Ventrites with yellowish-white pubescence not obscuring integument; apex of ventrite V widely notched.

Dimensions in mm. Total length, 6.35; prothoracic length, 1.25; anterior prothoracic width, 1.50; posterior prothoracic width, 1.45; widest prothoracic width (between apices of lateral tubercles), 1.90; humeral width, 2.25; elytral length, 4.50.

Type material. Holotype male from ECUADOR, Pichincha: Quito (around Cotopaxi Pungo Finca Hotel ) (pupa; imago emerged in captivity), 21.VI.2019, J. Vlasak col. ( MZSP).

Etymology. The name refers to the relatively short antennae compared to other species in the genus.

Remarks. In the key to genera of Neotropical Acanthocinini with erect setae and centrobasal crest on elytra proposed by Monné (1990), Leptocometes comes together with Onalcidion in the couplet 14. They share the follow- ing characters: elytra without longitudinal carina, mesoventral process about a half the width of a mesocoxal cavity. Leptocometes differs by the central or only post-median lateral tubercles of the prothorax while Onalcidion , have lateral tubercles slightly elevated and near the posterior lateral margin. However, there are species allocated in both genera with variations of these characteristics (for example: different shapes of prothorax; different shape of the lateral tubercles of the prothorax; different metafemoral shape; different shapes of elytral centrobasal crest (glabrous or with erect setae), indicating the need for a detailed taxonomic revision.

In the same way, some species currently placed in Onalcidion Thomson, 1864 , apparently need to be transferred to Leptocometes . The new species describe here agrees well with the type species of Leptocometes : body shape; prothoracic shape; shape of the lateral tubercles of the prothorax; centrobasal elytral crest; presence of erect elytra setae; length of metatarsomere I, etc. Accordingly, we think that the inclusion in the genus is well supported.

Leptocometes brevicornis sp. nov. is similar to L. hispidus Bates, 1881 ( Fig. 22 ), but differs as follows: antennae in male much shorter, reaching elytral apex on anterior third of antennomere VII; pronotum without blackish circular spot on each side of posterior third; long and erect elytral setae sparser, not distinctly visible laterally in dorsal view; upper eye lobes narrower, and distance between then slightly larger than three times the width of one lobe. In L. hispidus male, the antennae are much longer (see photographs at Bezark 2020), reaching elytral apex about apex of antennomere V, pronotum has blackish circular spot on each side of posterior third, long and erect elytral setae more abundant, distinctly visible laterally in dorsal view, and the upper eye lobes are wider, and the distance between them is twice the width of one lobe. It is also somewhat similar to L. umbrosus (Thomson, 1864) ( Fig. 23 ), but differs by the elytral pubescence pattern and color, erect elytral setae slightly distinct (very distinct in L. umbrosus ), especially laterally in dorsal view, and apex of metafemora not reaching elytral apex (slightly surpassing in L. umbrosus ).

Figures

FIGURES 18–23. 18–21) Leptocometes brevicornis, holotype male: 18) Dorsal habitus; 19) Ventral habitus; 20) Lateral habitus; 21) Head, frontal view. 22) Leptocometes hispidus, holotype male, dorsal habitus. 23) Thitonus umbrosus, holotype male, dorsal habitus.