Saprinus (Saprinus) nitiduloides Fairmaire, 1883

Lackner, Tomas & Leschen, Richard A. B., 2017, A monograph of the Australopacific Saprininae (Coleoptera, Histeridae), ZooKeys 689, pp. 1-263 : 134-141

Saprinus (Saprinus) nitiduloides Fairmaire, 1883 Figs 477, 478-486, 487-493, 755

Saprinus nitiduloides Fairmaire, 1883: 3.

Type locality.

Papua New Guinea: The Duke of York Islands: Mioko Island.

Type material examined.

Saprinus nitiduloides Fairmaire, 1883: Lectotype, present designation, ♂, side-mounted on a triangular mounting card, with terminalia glued on another triangular card under the specimen, right metatarsus missing, with the following labels: "Fairmaires / unique specimen / given me in Paris / 8.5.[18]88" (written); followed by: " Saprinus / nitiduloides / Fairm. /Mioko" (written); followed by: "G. Lewis Coll. / B.M. 1926-369." (printed); followed by: “Type” (round, red-margined label); followed by: “09-087” (yellow, pencil-written label, added by the senior author); followed by: " Saprinus / nitiduloides / Fairmaire, 1883 / LECTOTYPE / des. T. Lackner ‘11” (red label, written) (BMHN). Although Fairmaire (1883:3) does not mention the number of specimens he based his description of S. nitiduloides on, he does mention the sex of the species: male. It is presumed that Fairmaire had only one specimen at hands and he examined its sex. The specimen discovered in BMNH bears Lewis’ note that it was “Fairmaire’s unique specimen given me in Paris". However, because of the uncertainty of the number of specimens used for the species’ description we herein designate its lectotype to fix the species identity.

Additional material examined.

PAPUA NEW GUINEA. New Britain: 1 ♂, Duke of York, date and collector unknown (BMHN); 1 ♂, ditto, but coll. J. Schmidt (ZMHUB); 8 ♂♂ + & 7 ♀♀, Ralum, 30.v.1896, E. Dahl S. (ZMHUB; 3 ♂♂ + 1 ♀ in coll. TLAN); 1 ♂, Gisiluve, Nakansi Mts., 1050 m, 26.vii.1956, R.J. Ford Jr. (BPBM); 1 ♀, Vunakanau, Gazelle Peninsula, 26.v.1956, J.L. Gressit (TLAN).

SOLOMON ISLANDS. 1 ♀, Guadalcanal, Aula, date and collector unknown (BMHN).

Biology.

Unknown, presumably similar to congeners.

Distribution.

Papua New Guinea: New Britain; Solomon Islands: Mioko, Guadalcanal (Fig. 755).

Remarks.

The specimens from New Britain are generally more sparsely punctated than are those from Solomon Islands or islands of Duke of York.

Re-description.

Body length: PEL: 3.00-4.35 mm; EL: 1.75-2.85 mm; APW: 1.10-1.55 mm; PPW: 2.40-3.25 mm; EW: 2.55-3.60 mm.

Body (Fig. 477) rectangular oval, convex, cuticle dark brown, shining, with slight metallic luster, pronotum darker, piceous black; elytra lighter; legs, mouthparts and antennal scape castaneous brown; antennal club darker.

Antennal scape (Fig. 478) black, slightly thickened, finely punctate, with two setae; antennal club covered with dense short sensilla intermingled with sparse longer erect setae; sensory structures of antennal club not examined.

Mandibles dorso-laterally finely punctate, rounded, mandibular apex acute, sub-apical tooth on left mandible obtuse; labrum finely and sparsely punctate, convex, with deep median depression; labral pits present, each with a single labral seta; other mouthparts not examined.

Clypeus (Fig. 478) sloping down laterally, finely punctate; frontal stria weakened medially, complete, prolonged onto clypeus, straight, supraorbital stria slightly carinate; frontal disc (Fig. 478) finely punctate, punctures separated several times their diameter, on posterior third often punctation disappears completely; small fovea present on posterior fourth medially; eyes convex, well visible from above.

Pronotal sides (Fig. 477) moderately narrowing anteriorly, apical angles prominent, pronotal depressions present, shallow to moderately deep; anterior incision for head deep; marginal pronotal stria complete (not reaching pronotal base in some individuals), carinate, visible along its entire length from dorsal view; pronotal disc laterally with a band of deep dense elongate punctures originating approximately in pronotal depressions, not reaching basal angles of pronotum, between it and pronotal margin a narrow smooth band present; rest of the pronotal disc with only scattered microscopic punctation, almost glabrous in some individuals; double row of fine ovoid punctures present along pronotal base not reaching ante-scutellar area; tiny ante-scutellar fovea present in several individuals; pronotal hypomeron glabrous; scutellum small, visible.

Elytral epipleura with sparse fine punctures, almost glabrous in some individuals; marginal epipleural stria complete; marginal elytral stria well impressed and slightly carinate, continued as complete (weakened) apical elytral stria. Humeral elytral stria well impressed on basal third, usually connected to long inner subhumeral stria; four dorsal elytral striae 1-4 well impressed, in fine punctures, striae normally reach or even slightly surpass approximately elytral half apically, usually about the same length, but can be variously shortened, intermittent or erased, but usually fourth stria the shortest, basally not connected with sutural elytral stria; sutural elytral stria well-impressed, in fine punctures, abbreviated on basal fourth, apically connected with apical elytral stria; between first and second elytral stria deep sparse longitudinal strioles present; elytral disc on apical half (roughly) punctate, punctures fine, sparse, separated by several times their diameter; punctures not becoming denser apically.

Propygidium (Fig. 479) densely punctate, punctures separated by their own to twice their own diameter; pygidium (Fig. 479) with similar, but sparser punctation, interspaces in propygidium imbricate.

Anterior margin of median portion of prosternum (Fig. 480) almost straight, rounded laterally; marginal prosternal stria present laterally and also as medial fragment; prosternal process between carinal prosternal striae flat, sparsely and finely punctate, on anterior third distinctly convex, surface near united apices of carinal prosternal striae distinctly depressed; carinal prosternal striae carinate, parallel on basal two-thirds, on apical third slightly divergent and thence slightly convergent (can be also almost parallel-sided along their entire course), united in front (Fig. 480); lateral prosternal striae carinate, rather short, apically attaining carinal prosternal striae at about two-thirds of their length.

Anterior margin of mesoventrite (Fig. 481) distinctly inwardly arcuate; discal marginal mesoventral stria well impressed, carinate, shortened laterally; disc with sparse fine punctation, punctures becoming larger near meso-metaventral suture (occasionally disc entirely glabrous); meso-metaventral sutural stria indicated by a (sparse) row of large punctures; intercoxal disc of metaventrite flattened, in male with longitudinal median depression; disc of metaventrite for the most part almost smooth, surface around longitudinal depression with scattered microscopic punctation, punctures of various sizes, along posterior margin several rows of punctation appear (in several specimens disc almost glabrous); lateral metaventral stria (Fig. 482) well impressed, carinate, almost straight, shortened; lateral disc of metaventrite (Fig. 482) slightly concave, with dense shallow large setigerous punctures; metepisternum (Fig. 482) similar, but with deeper and larger punctures without setae, on fused metepimeron punctures becoming much sparser; metepisternal stria present along fused metepimeron, along metepisternum present as short intermittent fragments; occasionally complete.

Intercoxal disc of first abdominal ventrite completely striate laterally; disc along basal and lateral margins with shallow punctures of various sizes; rest of sternite with scattered microscopic punctation.

Protibia (Fig. 483) slightly dilated, outer margin with around ten very low teeth topped by large denticle, denticles diminishing in size proximally; setae of outer row regular, short; protarsal groove shallow; anterior protibial stria present on basal two-thirds, next obliterated; setae of median row shorter and much sparser than those of outer row; two tarsal denticles present near tarsal insertion; protibial spur bent, growing out from apical margin of protibia; outer part of posterior surface (Fig. 484) slightly obscurely variolate, separated from glabrous and narrow median part of posterior surface by a definite stria bearing a row of setae; posterior protibial stria complete, bearing almost along its entire length dense row of setae; inner row of setae double, setae dense, shorter but finer than those of posterior protibial stria.

Mesotibia (Fig. 485) slender, outer margin with a row of sparse long denticles growing in size apically, another row of much shorter sparser denticles situated on anterior surface of mesotibia; setae of outer row regular, thick, almost as long as denticles themselves; setae of median row shorter and finer; posterior mesotibial stria shortened apically; anterior surface of mesotibia (Fig. 486) sparsely punctate; anterior mesotibial stria almost complete; mesotibial spur stout, short; apical margin of mesotibia anteriorly with two short denticles; inner margin of mesotibia with sparse row of short setae; claws of apical tarsomere slightly bent, shorter than half its length; metatibia slenderer and longer than mesotibia, in all aspects similar to it, but denticles on outer margin much shorter and sparser.

Male genitalia. Eighth sternite (Figs 487-488) fused medially, apex with several microscopic setae, vela present, adorned with a row of microscopic setae; eighth tergite and eighth sternite fused laterally (Fig. 489). Ninth tergite (Figs 490-491) typical for the subfamily; tenth tergite inwardly arcuate, apical angles strongly sclerotized, bent; spiculum gastrale (Fig. 490) gradually dilated on most of its apical half; basal end slightly dilated. Aedeagus (Figs 492-493) parallel-sided, with parameres fused along their basal half (roughly); basal piece of aedeagus short, ratio of its length: length of parameres 1: 4; aedeagus slightly curved from lateral view; apex of aedeagus with a tiny patch of microscopic setae resembling a "suction cup".