Saprinus (Saprinus) rarus, Lackner, Tomas & Leschen, Richard A. B., 2017

Lackner, Tomas & Leschen, Richard A. B., 2017, A monograph of the Australopacific Saprininae (Coleoptera, Histeridae), ZooKeys 689, pp. 1-263 : 150-154

Saprinus (Saprinus) rarus sp. n. Figs 528, 529-537, 538-546, 764

Type locality.

Australia: New South Wales: N of Sydney: Pearl Beach at Broken Bay.

Type material examined.

Holotype, ♂, side-mounted on a triangular card, right metatibia broken off, glued to the same triangular card as the specimen, with male genitalia dismembered, glued to the same mounting card as the specimen, with the following labels: "Australia, / N of Sydney, / Pearl Beach at Broken Bay / 7.iii.1997 / leg. D. Scherbakov" (printed); with a consecutive label: "Coll. of / A. Sokolov" (hand-written); with consecutive label: " Saprinus (s.str.) rarus / n. spec. HOLOTYPE / Det. T. Lackner & R. / Leschen 2013" (red label, hand-written) (MAMU).

Paratype, ♀, side-mounted on a triangular card, right mesotarsus broken off, glued to the same triangular card as the specimen with the following labels: "Blackdown / T’ l Q. / 14.5. [19]81 / N.W. Rodd" (printed-written); followed by: “♀” (beige label, printed); followed by: "Australian Museum / K 270235" (printed); followed by: " Saprinus (s.l.) / sp. / G. Arriagada det. 1990" (black-framed label, printed-written); "followed by: “10-115” (light-yellow pencil written label); followed by: " Saprinus (s.str.) rarus / n. spec. PARATYPE / Det. T. Lackner & R. / Leschen 2013" (red label, hand-written); followed by: "Photographed by / B. Rhode" (yellow label, printed) (MAMU); paratype, ♂, mounted on a mounting card, with the following labels: " 33°36'07"S; 151°19'17"E / AUSTRALIA: New South Wales, Palm Beach, 15. / VIII.1962, G.R.Wearne / Host: Nasutitermes walkeri (Hill)" (printed); followed by: "Australia: N.S.W / Palm Beach, / 15.viii.1962" (printed-written); followed by: "Coll., Host det. / G.R. Wearne" (written); followed by: "Host: / Nasutitermes / walkeri " (written); followed by: " Saprinus rarus / sp.n. PARATYPE / det. T. Lackner 2016" (red label, written) (CPK).

Biology.

Collected from the nest of the arboreal Tree termite ( Nasutitermes walkeri (Hill, 1942)). Based on the morphology (thickened and dilated antennal scape, tibiae) and collection circumstances, Saprinus rarus is presumed to be a specialized termitophile. This is the first record of a termitophilic Saprininae from the Australopacific Region and only the third case of termitophily in the subfamily in general (the two other taxa are: African Pilisaprinus verschureni ( Thérond, 1959) ihabiting dead termitaria of the genus Macrotermes ( Termitidae ) recorded from Congo, Ivory Coast and Benin and Nannolepidius braunsi (Bickhardt, 1921) found in nests of Hodotermes termites ( Hodotermitidae ) in the Cape Region of South Africa, respectively).

Distribution.

This species is known only from three Australian specimens: two males collected near Sydney (New South Wales) and a female collected in Blackdown Tableland National Park, near Rockhampton (Queensland) (Fig. 764).

Etymology.

The specific epithet ' rarus ' refers to the scarcity of this beetle in collections.

Diagnosis.

Saprinus rarus has fused parameres (Fig. 545); its elongate body (Fig. 528), dilated tibiae (Figs 536-537), thickened and dilated antennal scape (Fig. 529) and large, almost circular antennal clubs (Fig. 530) will differentiate this species from other species in the genus.

Description.

Body length: PEL: 3.50 mm; APW: 1.50 mm; PPW: 2.50 mm; EL: 2.25 mm; EW: 2.90 mm (only one specimen was measured). Body (Fig. 528) elongate, convex, pronotum distinctly narrower than elytra, pronotum piceous, shining, elytra dark blue with metallic tinge; legs, mouthparts and antennal scape+funicle chestnut brown, antennal club lighter, amber colored, becoming progressively lighter apically.

Antennal scape (Fig. 529) strongly triangularly dilated, thickened, punctate, almost asetose (setae worn off?); antennal club (Fig. 530) large, almost circular, slightly depressed dorso-ventrally, entirely covered in dense short sensilla in the female paratype, while in the male holotype the lower third of the antennal club asetose, intermingled with sparse longer erect sensilla; sensory structures of antennal club not examined.

Mandibles with rounded outer margin, acutely pointed, sub-apical tooth on inner margin of left mandible not examined; labrum slightly depressed medially, labral setae not examined (worn off?); terminal labial palpomere elongated, its width about one-third its length; mentum (Fig. 531) almost square-shaped, anterior margin medially with prominent notch, surface around it with four long setae, anterior angles each with two shorter setae; lateral margins with a single row of even shorter sparse ramose setae, disc on apical half (roughly) with few scattered setae of various sizes (none of these setae are as long as those in the anterior corners or near median notch), basal half (roughly) asetose; terminal maxillary palpomere elongated, its width about one-third half its length, other mouthparts not examined.

Clypeus (Fig. 529) rectangular, flattened, with slight median depression, rounded laterally, anterior angles slightly convex, with dense shallow fine punctures; frontal stria (Fig. 529) complete; frontal disc (Fig. 529) anteriorly flattened, entirely punctate, punctures shallow, separated by about their own to twice their diameter, postero-median part of frontal disc with distinct fovea; eyes flattened, visible from above.

Pronotal sides (Fig. 528) widest on basal third, gradually convergent apically, apical angles prominent, marginal pronotal stria complete, carinate laterally, weakened behind head; disc almost entirely punctate, punctures round, deep, medially separated by their own to several times their diameter, laterally creating a band of denser and coarser punctation, between it and lateral pronotal margin a narrow impunctate band present; pronotal hypomeron glabrous; scutellum very small.

Elytral epipleura finely punctate; marginal epipleural stria thin; marginal elytral stria well impressed, thin, continuous along elytral apex as apical elytral stria; humeral elytral stria joined with inner subhumeral stria creating thus a complimentary dorsal elytral stria; four dorsal elytral striae 1-4 present, first the longest, slightly surpassing elytral half, second and third each slightly shorter, fourth stria the shortest, present as a short fragment on basal elytral sixth; sutural elytral stria abbreviated basally, in the female paratype present as a short fragment on (roughly) basal elytral third; in the male holotype entirely missing. Entire elytral disc very coarsely and densely punctate, punctures separated approximately by their diameter, between them another kind of much finer sparser punctures present, interspaces between punctures imbricate; before apical elytral stria punctation weakens, becomes much finer and sparser.

Propygidium (Fig. 532) almost completely exposed, covered with dense but shallow punctures separated by less than half their own diameter; punctation of pygidium (Fig. 532) sparser, but still very dense, punctures separated by less than their diameter, becoming sparser and finer near pygidial apex, interspaces imbricate.

Anterior margin of median portion of prosternum (Fig. 533) straight; marginal prosternal stria inconspicuous; prosternal process between carinal prosternal striae flattened, in sparse fine punctures, laterally with sparse small oval punctures, interspaces imbricate; carinal prosternal striae (Fig. 533) carinate, slightly divergent anteriorly and united in front under a rounded loop; lateral prosternal striae carinate, convergent anteriorly, attaining prosternal process near united apices of carinal prosternal striae.

Discal marginal mesoventral stria laterally well impressed, medially interrupted (Fig. 534); disc with sparse punctures of various sizes separated by several times their diameter; meso-metaventral suture fine; meso-metaventral sutural stria impressed as a row of large shallow punctures; intercoxal disc of metaventrite medially in female with shallow depression, while in the male this depression is deeper; larger punctures appear mostly along median longitudinal line and behind metacoxae, rest of metaventrite with sparse microscopic punctation. Lateral metaventral stria (Fig. 535) well impressed, almost straight, ending short of metacoxa; lateral disc of metaventrite (Fig. 535) depressed, with round shallow large punctures; metepisternum evenly punctate with even denser punctation; lateral metepisternal stria (Fig. 535) present, deeply impressed, absent on fused metepimeron.

Intercoxal disc of first abdominal ventrite completely striate laterally; surface of disc with scattered punctation, punctures becoming sparser and finer medially.

Protibia (Fig. 536) dilated, outer margin with three short triangular teeth topped by short denticle, followed by another short denticle; setae of outer row very short, sparsely paced; setae of median row inconspicuous; protarsal groove very shallow, al most non-existent; protibial spur tiny, growing out from anterior protibial margin; anterior protibial margin ventrally with three tiny denticles; anterior protibial stria complete, very fine; outer part of posterior surface of protibia (Fig. 536) knobby; median part of posterior surface glabrous, separated from outer part by a definite fine stria with minuscule setae; posterior protibial stria complete, with regular minuscule setae turning into two minuscule denticles apically; inner margin with single row of sparse microscopic setae.

Mesotibia dilated, outer margin with 5 widely spaced short denticles growing in size apically; setae of outer row sparse, minuscule; setae of median row inconspicuous; posterior mesotibial stria not examined; anterior surface of mesotibia convex medially; anterior mesotibial stria complete; mesotibial spur short; claws of apical tarsomere short, less than half its length; metatibia (Fig. 537) basically similar to mesotibia, but denticles of outer margin even sparser than those of mesotibia and metatibial spur longer.

Male genitalia. Eighth sternite (Figs 538-539) completely fused medially, apically with asetose velum covered with pseudo-pores, apex of 8th sternite with several short setae. Eighth tergite (Fig. 539) basally with deep emargination, apex only slightly emarginate; 8th sternite and tergite fused (Fig. 542). Ninth tergite (Figs 543-544) medially with strong sclerotization, with pseudo-pores. Apex of spiculum gastrale (Fig. 540) strongly sclerotized, basal end outwardly arcuate. Aedeagus with parameres separated on apical half (Fig. 545), curved, apex of parameres with setae (Fig. 546).