Metabacetus hermani, Will & Park, 2008

Will, Kipling W. & Park, Jong Kyun, 2008, A New Species Of The Oriental Abacetine Genus Metabacetus Bates, 1892 (Coleoptera: Carabidae) And A Key To The Species Of The Genus, The Coleopterists Bulletin 62 (2), pp. 189-196 : 191-194

Metabacetus hermani new species

Type Material. — HOLOTYPE. male. Verbatim label data: ‘‘ Vietnam Hatinh Pr., Raò An, 13 km W Huang Son, rt 8, 7 km S Nuòc S> t village, 18u 21 9 N, 105u15E, 1,150 m, IV-28-1998, leaf litter nr. stream, L.Herman # 2964’’; deposited AMNH . PARATYPE. male. Same data as holotype.

Etymology. Noun in genitive case formed from the name of the collector and excellent coleopterist, Lee Herman ( AMNH).

Type locality. — As given for holotype. Range — Vietnam ( Fig. 1 ) .

Recognitory Diagnosis. — Of the large-sized species in the genus ( Table 1.) with the prosternum not or only shallowly sulcate medially near apex, M. hermani is most similar to M. immarginatus from which it differs by being distinctly iridescent and having a more sinuate and reflexed pronotal base.

Description. — Large size for genus, overall body length 8.0– 8.3 mm. Deep black color and shiny throughout body, dorsally and ventrally; elytra slightly duller, pronotum and elytra iridescent; antennae, mouthparts, legs, pronotal margins, and elytral epipleura paler rufo-piceus; coxae concolorous with ventral surface.

Head. Eyes very prominent, form hemiobovate, ocular ratio 0.62 (width between eyes/width over eyes at midpoint); two pairs of supraorbital setae; microsculpture on dorsum shallow, reticulate microlines and sculpticells scarcely visible (evident at 25 3); frontal impressions deep, elongate divergent, ending near anterior supraorbital seta; clypeus very short, smooth, clypeo-frontal suture nearly effaced; mentum clearly broader than long, anterior margin shallowly emarginate; epilobes moderately prominent, short triangular; mentum tooth with simple rounded apex; mentum glabrous; paramedial pits distinct, deep, sharply defined; suture between mentum and submentum present; submentum with two pairs of lateral setae; maxillary stipes with seta near base, palpifer with setae near apex, palpomeres glabrous, fusiform, nearly equal in length; labial palpi fusiform; palpomere 2 longer than 3, with 2 large medial setae; 2 otherwise glabrous, 3 with small scattered setae; labrum with six setae on apical margin, margin slightly concave medially; mandibles with well defined and glabrous scrobe, form elongate, apex slightly hooked and sharply pointed; antennae long, reaching beyond base of pronotum; antennomeres 1–3 glabrous except for large seta on dorsum of 1 and 2, and ring of four to five at apex of 3; antennomere 4 densely pubescent from near base; antennomeres 5–11 with dense short pubescence throughout, four to six longer setae in ring around apices.

Thorax. Pronotum (Fig. 2,3) very shiny and iridescent throughout; microsculpture not evident except at high magnification (50 3), surface impunctate, form quadrate, broader than long, widest at or just before middle, side margins slightly and evenly rounded to just apicad basolateral setae and then nearly straight to hind angles, basal margin straight between basal impressions, anterior margin with front angles not protruding; hind angles about right angled and very slightly reflexed; two pairs of lateral setae, one pair anterad middle in lateral groove, one pair touching lateral bead near hind angles; lateral marginal bead continuous from front angles to hind angles, but sharply narrowed at hind setae, not prolonged along base; anterior submarginal sulcus absent; medial longitudinal sulcus fine, sharp ending well before apex and base.

Elytra ( Fig. 3 ) parallel-sided, convex, broadly rounded at apex with external plicae; microsculpture scarcely evident, surface moderately shiny, iridescent; striae deeply impressed and minutely punctate throughout; parascutellar stria connected to stria 1; basal section of stria 1 absent; basal margin entire; intervals very slightly convex throughout; interval 9 with usual umbilicate row of 13 setae; two additional setae in striae 7 near apex of each elytron; flight wings full, folded at apex; prosternum and proepisternum glabrous, very shiny and iridescent; mesosternum with few shallow punctures; metepisternum form elongate, densely and shallowly punctate; metepimeron large, broadly rounded; metasternum laterally densely punctate; protrochanter with medial seta; profemur anterior face with two to three medial and one subapical setae; dorsal face with three setae; ventral face glabrous; posterior face with three setae; protibial antennal cleaning organ well developed, with two clip setae; cleaner setal row extending dorsally, ending at larger medial seta; ventral ctenidia prominent; both proximal and distal spurs long and sharply pointed; Pro-, meso-, and metatarsomeres symmetrical shaped, meso- and metatarsomeres 1–4 ventrally with two rows of setae; 1–4 with two apical setae, 1–2 with additional apicomedial setae; protarsomeres 1–3 in male stout, broadly and symmetrically expanded with two rows of dense articulo setae ventrally, 4 very small and only slightly expanded with two rows of long setae; tarsomere 5 ventrally glabrous, dorsally with two setae; claws smooth; mesocoxa with one seta mesad, one laterad; mesotrochanter with one seta near base; mesofemur anterior face with basal and medial setae, dorsal face with 10–14 setae in row along length, posterior and ventral faces glabrous; mesotibia with four rows of stout spines and mesal row of finer, denser spines; two apical spurs; apical ctenidium well developed; mesotarsomeres more elongate than protarsomeres, tarsomere 1 slightly longer than length of 2 + 3, tarsomeres 1–2 with very shallow, incomplete external sulci; metacoxa with one medial and one lateral seta; anterior sulcus sinuate and complete, distant from anterior margin; metatrochanter with one basal seta, elongate, apex conical; metafemur anterior face with basal and medial (near ventral edge) setae, femur otherwise glabrous; metatibia with three rows of spines, medial row of finer thickness; two apical spurs; apical ctenidium well developed; metatarsomeres elongate, 1 equal to length of 2 + 3, 1–2 with external sulci.

Abdomen. Sterna shiny, glabrous except one pair paramedial setae on IV– VI; males with one pair at apex of VII. Sternum II with irregular cluster of punctures along base laterally; sternum VII apical margin smoothly rounded.

Male genitalia ( Fig. 4 ). Very simple. Median lobe of aedeagus apex straight, tip acuminate to rounded point; ventral surface with fine, low medial carina from bend in median lobe to basal third of blade ( Fig. 4A ). Female unknown.

Figures

Fig. 1. Distribution of Metabacetus species. 1 M. immarginatus crassulus, 2 M. immarginatus s.str., 3 M. loatinus, 4 M. hermani, 5 M. perakianus, 6 M. vandoesburgi, 7 M. arrowi; a,b,c, & d are localities of putative undescribed species represented as single specimens in the material examined.

Fig. 3. Metabacetus hermani, habitus image.

Fig. 4. Metabacetus hermani, male genitalia. A) median lobe, left lateral view. B) median lobe, tip ventral view, C) left paramere. D) right paramere.