Lucanus gradivus, Sato & Zilioli, 2018

Sato, Jin & Zilioli, Michele, 2018, Lucanus gradivus n. sp. from Vietnam, with new records of L. fujitai Katsura & Giang from Vietnam and Laos (Coleoptera, Lucanidae), Natural History Sciences 5 (1), pp. 71-75 : 71-73

Lucanus gradivus n. sp. ( Fig. 1 a-c)

Type material

Holotype ♂: Vietnam, Mu Cang Chai , Yen Bai Prov., VI. 2015, local collector leg. (deposited at the MSNM).

Paratypes

2 ♂♂, same locality as the holotype, V.2015 ( JSC, MZC) ; 1 ♂, Vietnam, Yen Bai Prov., VI.2015, local collector leg. ( JSC) ; 1 ♂, same locality, VI.2017 ( JSC) ; 2 ♂♂, Vietnam, Lai Chau Prov., VI.2015 ( JSC) ; 1 ♂, Vietnam, Ha Giang Prov., VI.2016 ( JSC) .

Holotype ( Fig.1-b ).

Length, including mandibles: 56.9 mm. Length without mandibles: 37.7 mm. Maximum head width, excluding mandibles: 17.2 mm.

Body slender, dark reddish brown, strongly punctate throughout, coated with sparse appressed yellowish pubescence. Elytra reddish brown with a narrow lateral and sutural black border; antennae and palpi black; legs with tarsi and coxae black, femora ferrugineous with base, apex and edges black, tibiae ferrugineous with black apices.

Head. Transverse (W/L: 2.10), matt, finely and irre- gularly rasp-like granulose, covered by a dense yellowish appressed pubescence and ridged along most of its profi- le. Head laterally broadly concave, posterolaterally with strong, wide, protruding beyond the eyes level, lobes; posterior margin widely concave. Anterolateral cephalic angles strongly protruding, more prominent than the eyes. Ocular canthus shorter than half eye’s diameter. Frons trapezoidal, slightly concave, fused with the epistoma. Transverse clypeal ridge strong, medially interrupted, laterally projecting as two blunt teeth; epistoma triangular, its apex rounded and fringed with yellowish hairs. Frontal ridge bisinuate, feebly raised and weakly convex. Mandible long, moderately robust, strongly bent at its proximal third, then almost straight up to its slightly curved apex; feebly shining, distinctly microsculptured proximally and sparsely punctured distally, with short, relatively sparse yellowish pubescence basally. Median tooth strong, triangular, sharp, slightly tilted forwards and upwards, placed after the midlength. Inner mandibular margin with a proximal strong serrated carina followed by a diastema, a strong blunt tooth, a serrated edge tipped by the median tooth, and 2-3 distal small denticles. Upper apical tooth bent upwards, with a sharp, well-marked dorsal carina; lower apical tooth shorter, conical, slightly directed forwards.

Antennal club 4-jointed; joints 8-10 bearing a strong, long, pubescent lamella; joint 7 with a shorter and thinner lamella, pubescent only anteriorly and with scattered setae elsewhere. Mentum wide, trapezoidal, matt, finely and irre- gularly granulose, covered with sparse yellowish pubescence, which is longer along mentum sides; anterior margin medially strongly convex and with broadly rounded corners.

Thorax. Pronotum transverse (W/L: 1.74), matt, finely punctured, coated with moderately dense, appressed yellowish pubescence; median longitudinal depression shallow, distinct in its anterior half, almost wanting in the posterior one; anterior corners rounded, posterior ones slightly protruding. Prosternal apophysis strong, prominent, apically rounded, laterally covered with yellowish pubescence. Scutellum transverse, rounded posteriorly, finely punctate and microreticulate, coated with appressed yellowish pubescence, except for a narrow smooth lateral margin. Elytra finely and densely punctate throughout, superficially microreticulate, coated with sparse yellowish pubescence, which is much longer and denser proximally. Shoulders toothed.

Legs slender, fairly shining, microreticulate with large, shallow, unevenly scattered punctures and with sparse, short yellowish pubescence, even shorter on fore tibiae. Fore tibiae with four (left) or five (right) spines on their outer edge, mid tibiae three-spinose; hind tibiae with two very small and weakly protruding preapical teeth.

Aedeagus robust (total length 5.97 mm) (Fig. 2), with short and apically widened flagellum; median lobe slen- der, shorter than parameres; the latter strongly curved, apically protruding.

Paratype males

Consistent with the holotype except for the usual allometric differences. Larger male with more pronounced morphological characters, and smaller one with, e.g., mandibles less curved and only feebly denticulated.

Derivatio nominis

This species is named after “Gradivus” a cult epithet of the god of war Mars, used here in reference of the combative and robust appearance.

Figures

Fig. 1 - a-c) Lucanus gradivus n.sp. a, c: paratype males, JSC; b: holotype male, MSNM. d-f: Lucanus fujitai Katsura & Giang. d: paratype male, Vietnam, Coll.Higuchi; e: holotype male, Vietnam, KPM; f: male, Laos, MZC.