Biribellus isabelae, Santos-Silva & Hernandez & Galileo, 2018

Santos-Silva, Antonio, Hernandez, Juan José Ramírez & Galileo, Maria Helena M., 2018, A new species of Biribellus Galileo, 1987 (Coleoptera, Cerambycidae, Prioninae, Anacolini) from Peru and key to species, Zootaxa 4531 (1), pp. 134-138 : 134-137

Biribellus isabelae , sp. nov.

( Figs 1–5 )

Description. Female. Integument mostly yellowish brown, irregularly more yellowish on some areas; part of frons, clypeus and labrum reddish brown; scape dark reddish-brown basally, black on remaining dorsal surface and on part of sides, reddish-brown on remaining surface; pedicel reddish brown basally, black on remaining surface; antennomeres III–XI black; mandibles black on inner margin and apex, yellowish-brown on remaining dorsal surface and ventrally, gradually from reddish-brown to black laterally; metanepisternum yellowish brown on basal and distal quarter, black on remaining surface; elytra pale yellow on basal 2/3 (slightly darker on circum-scutellar region), black on distal third; tibiae yellowish-brown basally, black on remaining surface.

Head. Frons narrow, concave, moderately coarsely, abundantly punctate except sparser punctures close to median groove; glabrous. Vertex coarsely, abundantly, punctate (punctures coarser than on frons, confluent close to lower eye lobes), except impunctate central area between antennal tubercles and upper eye lobes; area along median groove slightly, longitudinally tumid; with a few, minute yellowish-white setae emerging from some punctures between antennal tubercles and upper eye lobes. Area behind eyes coarsely, abundantly punctate (punctures shallower, moderately coarser, partially confluent behind lower eye lobes); with a few, minute yellowish-white setae behind lower eye lobes. Genae moderately finely, sparsely punctate; with a few short, erect yellowish-white setae toward ventral side. Antennal tubercles with punctures as on frons basally and frontally, smooth on remaining surface. Median groove distinct from clypeus to near prothoracic margin. Postclypeus wide, concave, coarsely, abundantly, partially confluently punctate on sides of wide central area, smooth centrally and laterally; with a few short yellowish-white setae on sides of wide central area. Labrum coplanar with anteclypeus on posterior half, inclined on anterior half; with moderately long, erect, sparse yellowish-white setae laterally and on anterocentral area. Mandibles coarsely, abundantly punctate dorsally and laterally; with long yellowish-white setae directed inward on basal 2/3 of inner black area, glabrous on remaining surface except a few short, erect yellowish-white setae on basal third. Gulamentum transversely striate on posterior third, slightly depressed, coarsely, abundantly, confluently punctate on anterior 2/3; with minute, sparse yellowish-white setae on depressed area. Distance between upper eye lobes 1.13 times length of scape; in frontal view, distance between lower eye lobes 1.08 times length of scape. Antennae 0.76 times elytral length, slightly surpassing midlength of elytra. Scape slightly, gradually widened toward apex; moderately coarsely punctate dorsally and laterally, nearly smooth ventrally. Pedicel moderately coarsely punctate except smooth distal area. Antennomeres III–VI coarsely punctate dorsally; antennomere III with elongate sensorial area at distal third (nearly undivided); antennomere IV with sensorial area divided by carina, with inferior area depressed from base to apex and superior area depressed on distal 2/3; remaining antennomeres with sensorial area from base to apex, divided by carina; dorsal surface of antennomeres VII–XI somewhat rugose-punctate, more so toward XI; distal antennomeres with a few minute, whitish setae distally. Antennal formula (ratio) based on length of antennomere III: scape = 0.55; pedicel = 0.24; IV = 0.60; V = 0.55; VI = 0.47; VII = 0.43; VIII = 0.38; IX = 0.34; X = 0.30; XI = 0.40.

Thorax. Prothorax transverse, 1.7 times wider than long (including laterocentral projection of pronotum). Pronotum convex except narrow flattened sides, glabrous; with five slightly elevated gibbosities, two on each side (both from dorsal surface to near lateral margin, posterior one larger), another somewhat triangular on center of posterior half; coarsely, sparsely punctate (punctures sparser on gibbosities); anterolateral angles rounded, posterolateral angles moderately acute, projected sideward; lateral projection triangular, moderately small, placed slightly after middle; anterior margin slightly sinuous, widely rounded and projected forward centrally; posterior margin sinuous, with central area rounded and distinctly projected backward. Hypomeron shallowly, coarsely punctate on anterior half, nearly smooth on distal half. Prosternum tumid centrally, slightly rugose-punctate (more so laterally); with a few minute yellowish-white setae laterally. Prosternal process coarsely, abundantly, confluently punctate; in lateral view, forming distinct, rounded projection ( Fig. 3 ); with short, decumbent, sparse yellowishwhite setae centrally, and long, erect yellowish-white setae toward apex. Mesoventrite slightly rugose-punctate. Mesanepisternum and mesepimeron shallowly, densely rugose-punctate; with short, sparse yellowish-white setae. Mesoventral process strongly, obliquely inclined toward its apex; apex with distinct tab-shaped projection on each side; with long, erect yellowish-white setae toward apex. Metanepisternum shallowly, coarsely, abundantly punctate; with short, moderately abundant yellowish-white setae on basal third, gradually shorter, sparser toward apex. Metaventrite moderately coarsely, abundantly punctate (punctures denser laterally close to mesocoxal cavities); metaventral process reaching about middle of mesocoxal cavities, somewhat elevated ( Fig. 3 ), tumid on each side of central discrimen, which reaches apex of metaventral process ( Fig. 5 ); with short, moderately abundant yellowish-white setae, except nearly glabrous area close to central discrimen. Scutellum glabrous, smooth except sparse punctures laterally; apex rounded. Elytra. Coarsely, abundantly punctate throughout, becoming confluently, slightly rugose laterally and apically except nearly smooth explanate outer margin; elytral carinae slightly marked; apex rounded with small projection at sutural angle. Legs. Femora coarsely, shallowly, sparsely punctate; with short, decumbent very sparse yellowish-white dorsally and laterally, longer, erect, more abundant ventrally on basal 2/3, especially on meso- and metafemora. Tibiae coarsely, abundantly, partially confluent punctate; with short, bristly, moderately abundant yellowish-white setae.

Abdomen. Ventrites finely, sparsely punctate; ventrite V slightly inclined at distal half, with posteriorly margin concave centrally; with moderately short, sparse, almost decumbent yellowish-white setae.

Dimensions (mm). Total length, 16.40; prothoracic length, 2.80; anterior prothoracic width, 3.95; posterior prothoracic width, 4.60; maximum prothoracic width, 4.75; humeral width, 6.45; elytral length, 12.50.

Type material. Holotype female from PERU, Loreto: Picuroyacu ( Rio Amazonas; 3°37’S / 73°15’W), 11.V.2010, J.J.R. Hernandez col. ( MUSM, former JJRH).

Etymology. The new species is named to honor Isabel Hernandez, mother of the second author.

Remarks. The general appearance of Biribellus isabelae sp. nov. is much similar to that of B. huedepohli ( Galileo, 1987) , but differs by the metasternal process distinctly wider, longitudinally sulcate by the central discrimen ( Fig. 5 ), and not distinctly elevate when viewed sideways ( Fig. 3 ). In female of B. huedepohli ( Fig. 7 ), the metasternal process is narrower, not longitudinally sulcate by the central discrimen ( Fig. 6 ), and is distinctly elevate when viewed sideways ( Fig. 8 ).

Figures

FIGURES 1–8. 1–5, Biribellus isabelae, holotype female: 1, Dorsal habitus; 2, Ventral habitus; 3, Lateral habitus; 4, Head, frontal view; 5, Metaventral process. 6–8, Biribellus huedepohli, holotype female: 6, Metaventral process; 7, Dorsal habitus; 8, Lateral habitus.