Saprinus (Saprinus) pseudodetritus, 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 : 144-149

Saprinus (Saprinus) pseudodetritus sp. n. Figs 511, 512-520, 521-527, 761

Type locality.

New Zealand: Chatham Islands: South East Island.

Type material examined.

Holotype, ♂, side-mounted on a triangular card, with terminalia extracted and mounted in Canada Balsam on a separate slide under the specimen, with following labels: "Chatham Is / N. 1970 / J.I. Townsend" (printed); followed by: "South East Island" (printed); followed by: "At night in bush" (printed); followed by: “09-082” (yellow, pencil-written label); followed by: " Saprinus (Saprinus) / pseudodetritus sp. n. / HOLOTYPE / Lackner&Leschen 2010" (red label, printed) (NZAC). Paratypes, 9 specs., same data as holotype, except for yellow label, that is present only on holotype (NZAC); 1 spec., "CHATHAM IS, N.Z. / Rangatira I / (South East I) / 1-14 Dec 1987 / J.S. Dugdale" (printed); followed by: "litter / under / Myosotidium " (printed-written) (NZAC); 1 spec., "CHATHAM IS, N.Z. / SE Island 10m / Northern Olearia / forest" (printed-written) (NZAC); followed by: "Fit trap 2 / Predominantly / Plagianthus / forest" (written) (NZAC); 1 spec., "CHATHAM IS, N.Z. / South East I / 13-16 Dec 1987 / A. Grant (DOC)" (printed) (NZAC); followed by: "Nest of / Pachyptila / vittata " (printed) (NZAC; 3 PT from SE Island collected by J.I. Townsend in coll. TLAN); 1 spec., "CHATHAM IS. N.Z. / South East I, 10-20m / 29.xi.1992 / J.W. Early" (printed); followed by: "On tree trunks at / night" (printed); followed by: " AMNZ 11324 / AUCKLAND / MUSEUM / NEW ZEALAND" (green label, printed) (AMNZ); 6 specs., ditto as above, but 27-28.xi.1992 and collected on bush floor at night (AMNZ). These paratypes bear specimen registration numbers (AMNZ numbers) as follows: 11325, 11326, 11327, 11328, 11329 and 11330; 4 specs., "NEW ZEALAND, CI / South East Island / 14.v.1996 P. Dilks / ex Chatham Island petrel / burrow litter" (printed); followed by: "ENTOMOLOGY / RESEARCH MUSEUM / (LUNZ) / Lincoln University / Canterbury, New Zealand" (green label, printed) (LUNZ); 2 specs., "NEW ZEALAND, CI / Rangatira / 27.xi.1992 / J.W.M. Marris" (printed); followed by: "on ground at base of tree / at night" (printed) (LUNZ); 9 specs., ditto, but 27-30.xi.1992, J.W. Early, R.M. Emberson & P. Syrett (pitfall traps in Olearia/ Plagianthus /Macropiper forest) (LUNZ); 3 specs., "NEW ZEALAND, CH / South East Island / Woolshed Bush / 20.i. 1998 R.M. Emberson / on ground at night" (printed) (LUNZ); 1 spec., NEW ZEALAND, CH / South East Island / 31.xii. 1998 R.M. Emberson / under dead broad billed / prions" (printed) (LUNZ); 1 spec., ditto, but on tree trunks at night (LUNZ); 4 specs., "NEW ZEALAND, CI / South East Island / Woolshed Bush / 15.i.1997, R.M. Emberson / on ground by petrel burrows" (printed) (LUNZ); 4 specs., "NEW ZEALAND, CH / Chatham Is, South East I, / Woolshed Bush / 19.-21.i.1998 / R.M. Emberson, J.W. Marris" (printed); followed by: "pitfall traps in coastal / broadleaved forest" (printed) (LUNZ); 4 specs., ditto, but 13.-17.i.1997 (LUNZ); 8 specs., "NEW ZEALAND, CI / Mangere I., Robin Bush / 30.xi.-3.xii. 1992 / J.W.M. Marris & J.W. Early / pitfall trap in bush" (printed) (LUNZ); 6 specs., "NEW ZEALAND, CH / Star Keys / 23.i.1998 J.W.M. Marris / under rock in low coastal vegetation (sward)" (printed) (LUNZ); 5 specs., "NEW ZEALAND, CI / Rangatira / 28.xi.1992 / P. Syrett / by petrel burrow at night" (printed) (LUNZ); 1 spec., ditto, but 29.i.1998 and on tree at night (LUNZ); 1 spec., "NEW ZEALAND, CI / Glory Scan Res / 30.xi.1992 / R.M. Emberson & P. Syrett" (printed) (LUNZ); 1 spec., "NEW ZEALAND, CI / Chatham I, Hapaupu / 2.xii.1992 / P. Syrett / on trees at night (printed) (LUNZ; 8 exs. in coll. TLAN); 1 spec., "Chathm. / gr.? (illegible)" (written); "New Zealand" (printed); "Pascoe / Coll. / 93-60" (printed); "this specimen is / most likely from / the Chatham Islands / T. Lackner, 2014" (written); " Saprinus pseudodetritus / sp. n. PARATYPE / Det. Lackner & Leschen, 2014" (red label, written) (BMNH).

Distribution.

New Zealand: Chatham Islands: South East Island, Mangere Island and Pitt Island (Fig. 761).

Biology.

Specimens of this species were found in litter under Myosotidium ( Boraginaceae ), and in Olearea ( Asteraceae ) and Plagianthus ( Malvaceae ) forests, in the nests and on dead Broad-billed prion ( Pachyptila vittata (G. Forster, 1777)) and near petrel burrows. The species is also nocturnal, and has been found on tree trunks and on the bush floor at night.

Diagnosis.

This is a distinctive New Zeland endemic (so far only collected on Chatham Islands) differing from other two, presumably closely related New Zealand species by matte dorsum covered with alutaceous microsculpture, a lightly colored antennal club, aciculate bases of elytral striae, as well as scratched-like punctation on apical third of elytra.

Diagnostic description.

Since S. pseudodetritus is rather similar to S. detritus and S. chathamensis we will provide only its diagnostic description here mostly outlining the chief differences between the three taxa. The figures, as well as male genitalia drawings are kept, for the sake of easier identification of the Australopacific taxa. The same approach is taken with the species S. chathamensis (see above). On the other hand, the species S. detritus , which was described originally as the first of the three New Zealand species, is provided with full detailed description. A light to dark brown species with matte bronze luster (opaque cuticle is due to presence of fine imbricate microsculpture, which can be worn in some specimens, especially on elytra); venter black, without imbricate microsculpture; legs, mouthparts and antennae rufous to rufo-castaneous; antennal club amber-colored to rufous. Body length: PEL: 3.25-4.25 mm; EL: 1.90-2.50 mm; APW: 1.20-1.50 mm; PPW: 2.40-3.10 mm; EW: 2.65-3.50 mm. Antennae (Figs 512-513) similar in structure to other two New Zealand endemics; sensory structures of antennal club not examined.

Mouthparts similar to those of S. chathamensis and S. detritus ; mentum (Fig. 514) quadrate, anterior and posterior angles slightly projected, anterior margin with deep median notch, surface around it with several longer setae, lateral margins apically with a single row of much shorter ramose setae, disc of mentum finely imbricate, with sparse short setae (similar to that of S. detritus ; Fig. 425). Clypeus and frons (Fig. 512) rather similar to those of S. chathamensis and S. detritus (compare with Figs 373 and 423). Pronotal sides (Fig. 511) on basal two-thirds moderately narrowing anteriorly, on apical third strongly narrowed, apical angles prominent. Generally, the pronotum of S. pseudodetritus is apically more narrowed than those of S. chathamensis and S. detritus (compare also Figs 372 and 422). Lateral band of punctures present, punctures not prominent, fine. Elytral surface around bases of striae aciculate; elytral disc on apical third (roughly) with elongate punctures separated by their own to several times their diameter. Configuration of the elytral striae very similar otherwise between species S. chathamensis , S. detritus and S. pseudodetritus (compare Figs 372, 422 and 511) with characteristically strongly shortened third dorsal elytral stria. Although elytral sculpture is also similar between species, the punctation of S. pseudodetritus is the finest of the three species; interspaces between punctures in S. pseudodetritus strongly aciculate. Propygidium and pygidium (Fig. 515) with fine small round punctures separated by about their diameter; interspaces in both cases imbricate. Prosternum generally similar to those of other two NZ species (compare Figs 377 with 426 and 516) antennal cavities for reposing antennal clubs large; carinal prosternal striae of S. pseudodetritus sub-parallel, while they are narrowing apically in S. chathamensis and slightly diverging apically in S. detritus .

Meso-and metaventrites (Fig. 517-518) similar to those of other two species, for direct comparison between the three species the reader is referred to the diagnostic description of S. chathamensis . Legs of S. pseudodetritus are generally similar to those of S. chathamensis and S. detritus .

Male genitalia. Eighth sternite (Figs 521-522) apically with several pseudo-pores, entirely fused, strongly sclerotized; apex of eighth sternite laterally with two tufts of several short setae; eighth tergite and eighth sternite fused laterally (Fig. 523). Ninth tergite (Figs 524-525) typical for the subfamily; anterior margin of tenth tergite inwardly arcuate; spiculum gastrale (Fig. 524) gradually dilated on apical half; apical end strongly sclerotized; basal end abruptly dilated, triangular, basal end outwardly arcuate. Aedeagus (Figs 526-527) subparallel, before apex slightly dilated; parameres fused along their basal half (roughly); basal piece of aedeagus short, ratio of its length: length of parameres 1: 6; aedeagus almost straight, only apically slightly curved from lateral view (Fig. 527). The male terminalia of S. detritus and S. pseudodetritus are very similar (compare Figs 432-438 with 521-527) and generally differ only in the structure of ae deagus, which is slightly constricted before apex in S. detritus while it is not constricted and tube-like in S. pseudodetritus . In lateral view, aedeadus of S. pseudodetritus is thicker than that of S. detritus (compare Figs 438 and 527).