Satrapister nitens Bickhardt , 1912 : redescription and tentative phylogenetic placement of a mysterious taxon ( Coleoptera , Histeridae , Saprininae )

The monotypic genus Satrapister Bickhardt, 1912 is redescribed and figured. Its tentative position in the recently performed phylogeny of the subfamily, inferred from a new analysis based on the available morphological characters is discussed. Lectotype of Satrapister nitens Bickhardt, 1912 is designated.


Introduction
Satrapister nitens Bickhardt, 1912 was described more than a hundred years ago by Bickhardt, one of the leading experts of the histerid taxonomy from the first half of the 20 th century, as the type species of the monotypic genus Satrapister Bickhardt, 1912.The species was described based on two specimens collected by A. Reclaire in Göttingen (Germany) in guano, originating from Peru and became a mystery practically since its description, both for its uncertain origin, biology and morphology.Its taxonomic placement was only briefly discussed by Bickhardt (1912), he compared the newly described taxon Satrapister with the genera Haeterius Dejean, 1833 (which belongs to a different subfamily Haeteriinae Marseul, 1857) and Saprinus Erichson, 1834, based on their respective external morphologies.In the original description, Bickhardt (1912) did not place Satrapister into subfamily; but later, in his catalogue of the family Histeridae (1916: 82), he placed it correctly into the subfamily Saprininae as the first genus of the subfamily.Mazur in his catalogues (1984,1997,2011) placed Satrapister between the genera Myrmeosaprinus Mazur, 1975and Euspilotus Lewis, 1907(Mazur 1984: 64); Saprinus and Euspilotus (1997: 232); and finally, between Microsaprinus Kryzhanovskij, 1976 andEuspilotus (2011: 189).Satrapister, together with Auchmosaprinus Wenzel, 1962 andParamyrmetes Bruch, 1929 was one of the three Saprininae higher taxa that were not included in the phylogenetic treatment of the subfamily (Lackner 2014d) because of its unavailability.Recently I have had the opportunity to inspect Auchmosaprinus and Satrapister, so Paramyrmetes remains the last Saprininae genus or subgenus unknown to me.In this paper the taxon is redescribed based on the type material as well as three newly discovered specimens from Peru, and complement the redescription with habitus images and drawings of the sensory organ of the antennal club and male genitalia.This work presents another contribution to my on-going revisionary work on the genera of the subfamily Saprininae (Lackner 2009a(Lackner -c, 2010(Lackner , 2011a,b;,b;Lackner 2012;Lackner 2013a,b,c;Lackner and Gomy 2013;Lackner 2014a,b,c,d;Lackner 2015;Lackner and Tishechkin 2014;Tishechkin and Lackner 2012).

Material and methods
The lectotype specimen was soaked in water overnight, removed from its original mounting card, cleared from dust and remaining glue with 70% ethanol and mounted on a triangular point for observation.Other specimens were observed under binocular microscope.Colour images were made by F. Slamka (Bratislava, Slovakia).Measurements were made by ocular micrometer.Body part terminology follows that of Ôhara (1994) and Lackner (2010) and the following acronyms of museum collections are used throughout the text: MUSM -Universidad Mayor de San Marcos, Lima, Perú (Olga Bracamonte Guevara); NCB -National Centre for Biodiversity Naturalis, Leiden, the Netherlands (Hans Huijbregts); SENA-SA -Servicio Nacional de Sanidad Agraria, Lima, Perú (Nuñez Sacarias De Dioses Elizabeth Yolanda); ZMHUB -Museum für Naturkunde, Berlin, Germany (Bernd Jaeger).Separate lines of the same label are demarcated by a slash (/).Abbreviations of morphological measurements follow Ôhara (1994) and are used throughout the text as follows:

APW
width between anterior angles of pronotum EL length of elytron along elytral suture EW maximum width between outer margins of elytra PEL length between anterior angles of pronotum and apices of elytra PPW width between posterior angles of pronotum.
Analytical methods.Cladistic analyses were based on the external structures and male genitalia.In total, 95 morphological characters (see Lackner 2014d for details) of adults were scored (multistate coding) and analyzed.Adult morphological characters were treated as non-additive; inapplicable characters were assigned a gap value ('-') and treated as equivalent to missing data ('?').The total number of ingroup taxa was 73 (taxa used in Lackner 2014d + S. nitens); cladograms were rooted with exemplars of Dendrophilinae Reitter, 1909(genus Dendrophilus Leach, 1817), Bacaniini Kryzhanovskij in Kryzhanovskij and Reichardt 1976(genus Bacanius LeConte, 1853), Abraeinae MacLeay, 1819(genus Chaetabraeus Portevin, 1929), and Anapleini Olexa, 1982(genus Anapleus Horn, 1873).The taxa selected as outgroup representatives were selected based on the existing phylogenies of the Histeridae by Ślipiński and Mazur (1999) and Caterino and Vogler (2002), which suggest that representatives of Dendrophilinae and Abraeinae are amongst the best contenders for the Saprininae sister groups.The most parsimonious trees (MPTs) were searched using PAUP 4.0B10 (Swofford 2001) with 1000 random addition replicates of tree bisection-reconnection branch swapping.All characters were unordered and equally weighted.Bootstrap (BS) values (Felsenstein 1985;Sanderson 1995) were calculated by resampling with 1000 replications using simple searches while holding one tree at each step and swapping on the best tree.Additional branch support was examined using decay indices (DIs; Bremer 1994), calculated by the program TreeRot (Sorenson 1999).Character states were optimized using MacClade 4.08 (Maddison and Maddison 2005); only the unambiguous optimizations are shown on the tree (Fig. 14A).The cladogram was graphically depicted using the FIGTREE program (Rambaut 2007) and subsequently redrawn using Adobe Illustrator CS5.

Differential diagnosis.
As I am not familiar with most of the South American taxa of the species-rich genus Euspilotus, I hesitate to provide a clear-cut differential diagnosis of the genus Satrapister.It is, however, most readily distinguishable from the majority of the South American species of the subfamily that I am familiar with by its elongate-oval body form, reduced and flattened eyes and almost complete lack of elytral striation.
Biology.Unknown, the type specimens were found in guano originated from Peru; reduced eyes can indeed indicate its inquilinous habits.The other three specimens do not carry any biological data on their labels.
Distribution.Bickhardt (1912: 232) following the description of S. nitens in Latin gave 'South America ?' as its terra typica, but explained further in the text in German that the two specimens he examined were found in Göttingen by Dr. A. Reclaire in 'Peru-Guano', and that was why he opted for South America as the continent of origin.The type locality 'South America ?' was repeated by Mazur (1984Mazur ( , 1997Mazur ( , 2011)), followed by 'Peru ?'.The three non-type specimens collected in the years before and after WWII originate from two tiny islands off the Peruvian coast: Isla Don Martín and Isla de Pescadores [=Isla Grande].Both these islands serve as important refugia and nesting grounds for numerous species of seabirds and are known to contain large amounts of guano (Cushman 2014).
Remarks.Bickhardt (1912) described the type species of this genus based on two specimens: one of them was to be kept in his private collection (now ZMHUB) and the second one was to be kept at the private collection of Dr. H.J. Veth (later acquired by NCB), who had sent him the two type exemplars found in guano allegedly originating from Peru in Göttingen, Germany by Dr. A. Reclaire (see also above).During my visit of ZMHUB, I found one of the two specimens of S. nitens (a female) that had been designated a lectotype by G. Arriagada (Santiago de Chile, Chile); however, this designation has apparently never been published.Recently, I discovered the second specimen, kept in the collection of NCB; this was most likely Veth's specimen.The specimen in ZMHUB is almost completely fallen apart and its body parts are glued on two separate mounting cards.The other specimen, housed in NCB was also observed to be badly damaged and very fragile.Judging from the state of the type specimens, I infer that they arrived to Europe from their alleged homeland (South America, Peru) already dead.
Description.Body (Figs 1-2) PEL: 1.50-1.70mm; APW: 0.625-0.65 mm; PPW: 1.00-1.125mm; EW: 1.25 mm; EL: 1.00 mm; colour (including body appendages) light brown to castaneous, antennal club amber-coloured.Clypeus flat, with scattered punctuation; labrum with wide median depression, with two long labral setae arising from each labral pit; mandibles rather slender, left mandible slightly longer than right, both mandibles pointed apically, sub-apical tooth on left mandible situated approximately in mandibular mid-length, obtuse; vague vestiges of frontal stria present anterad eyes, frontal + supraorbital striae otherwise absent; frontal disc flat, with scattered punctuation, punctures separated by several times their diameter, on posterior margin with distinct fovea medially; occipital stria fine, complete.Antennal scape slightly thickened, antennal club round, sensory structures of antennal club (Fig. 3) in form of one stipe-shaped vesicle situated under round sensory area on internal distal side of the antennal club dorsally, bridgelike connected with another sensory area.Antennomeres 1-8 with distinct setae.Eyes small (reduced?),flattened, invisible from above; surface above eyes on frontal lateral margins with distinct regular microscopic setae.
Pronotal hypomeron punctate, with distinct regular microscopic setae, lateral pronotal margins (Fig. 1) on basal two-thirds almost sub-parallel, on apical third narrowing, anterior pronotal angles obtuse.Pronotal disc laterally with sparse, rather deep elongate punctures separated by their own to several times their diameter; medially disc with scattered microscopic punctuation.Marginal pronotal stria thin, but carinate and complete; pronotal base with a vague row of tiny punctures.Scutellum small, triangular.
Elytral epipleuron with several irregular wrinkles and few punctures, otherwise smooth; marginal epipleural stria fine, complete, marginal elytral stria carinate and complete; apical elytral stria obliterated on half its length.Oblique humeral stria deeply impressed on basal elytral fourth; in one specimen a median fragment of inner subhumeral stria as well as a basal fragments of elytral striae 1-2 present; in rest of specimens all other elytral striae, except for short basal fragment of fourth dorsal elytral stria that is basally connected to almost complete sutural elytral stria completely lacking.Elytral disc with scattered punctures separated by several times their diameter.
Propygidium and pygidium with punctuation similar to the elytra, but punctures deeper and denser, separated approximately twice their diameter.
Mesoventrite (Fig. 2) sub-trapezoid, convex, sparsely punctuate, marginal mesoventral stria thin, weak; meso-metaventral sutural stria absent; metaventrite almost smooth, only with several scattered punctures becoming denser along metaventral base; lateral metaventral stria straight, thin, vaguely impressed, shortened; lateral disc of metaventrite with dense deep, almost confluent punctures fringed with long amber setae; metepisternum with similar punctuation.Legs: protibia slightly dilated, with 9-11 low teeth topped by rather long thin curved denticles diminishing in size in proximal direction, protarsal groove shallow, protibial spur short and stout, growing out from apical protibial margin, further characters of protibia not examined.Mesotibia on outer margin with a row of low teeth topped by long, slender amber-coloured denticles, setae of outer row dense and rather long; setae of median row finer and shorter; on anterior face of mesotibia another row of shorter dense amber denticles present, mesotibial spur stout and well-developed; metatibia slightly longer than mesotibia, denticles on outer metatibial margin more closely-set; metatarsal claws short, bent, about halflength of terminal metatarsal segment; other characters of legs not examined.
Cladistic analysis.Results of the tree reconstruction analyses are shown in Figure 14A.Heuristic search resulted in 1026 equally parsimonious trees of tree length (TL) = 582, CI = 0.33, RI = 0.66.The strict consensus of the equally parsimonious trees had the following characteristics: TL = 701, CI = 0.29, RI = 0.57.The strict consensus tree is mostly resolved, but bootstrapping resulted in low support values for most of the recovered branches.

Discussion
The genus Satrapister was, due to its unavailability not included in my phylogeny of the subfamily, which was based on the morphological characters of the adults alone (Lackner 2014d).Using the analytical methods of my previous work (Lackner 2014d; see also above) I coded the characters of Satrapister as well as male genitalia of another South American genus Phoxonotus Marseul, 1862 that were not available previously and performed the heuristic search.The analysis yielded a tree topology, which is in deeper branches largely congruent with my previous results, with the exception of the newly included Satrapister, naturally (Fig. 14A).The South American attaphilous genus Phoxonotus was recovered in my previous analysis (Lackner 2014d; see Fig. 14B of the present paper) as a member of a small monophyletic clade of mostly inquilinous, North American genera (with the exception of the Middle-Asian genus Turanostyphrus Tishechkin, 2005 whose type species is known only from a single specimen and whose mouthparts dissections were not possible to study and whose spiculum gastrale was not available for character coding).With the forthcoming revision of the genus Phoxonotus (Lackner, in press) I have had the possibility to examine numerous specimens of its type species, P. tuberculatus Marseul, 1862 and coded the male genitalia into the original matrix.Although the position of P. tuberculatus on the recent tree (Fig. 14A) is somewhat different from that of Lackner (2014d) (Reitter, 1904) in a grade basal to a large clade of mainly psammophilous taxa with largely unresolved inter-relationships.The support for the clade including P. tuberculatus of Lackner (2014d) is low and based only on several homoplastic characters.Although this has been attributed to the lack of a male genitalic characters of Phoxonotus previously and the missing characters of the rare Middle-Asian Turanostyphrus ignoratus (Lackner 2014d: 548) the situation is no different even after inclusion of the male genitalia characters of Phoxonotus, and the support for the branches is low and based on mostly homoplastic characters again.
The position of the species Satrapister nitens on the cladogram, in the same grade as P. tuberculatus must, due to the low support of the most branches, be regarded as preliminary and tentative.Its morphological characters are a mix of plesiomorphic (e.g.absent supra-orbital striae) and apomorphic ones (e.g. the presence of only a single, stipe-shaped vesicle or the 8 th sternite and tergite of male genitalia fused laterally).
Based on the reduced eyes as well as its presence in guano there is room for speculation that S. nitens is indeed an inquilinous species.The incomplete biological data and lack of larval and/or molecular characters of this species considerably blur the picture of its exact allegiance with the rest of the subfamily.
Thanks are due to the curators of the above-mentioned institutions that loaned me the two type specimens as well as to Gerardo Arriagada (Santiago de Chile, Chile) who sent me the three specimens of S. nitens collected in the 20 th century.Andreas Pütz (Eisenhüttestadt, Germany) as well as Michael Geiser (London, UK) are being thanked for their help with German language.This research received support from the SYNTHESYS Project http://www.synthesys.info/,which is financed by the European Community Research Infrastructure Action under the EP7 Integrating Activities Program as well as it re-©https://dez.pensoft.net/;Licence:CC BY 4.0 ceived support from the grant of the Faculty of Forestry and Wood Sciences, Specific research, grant n.B06/15, Czech University of Life Sciences Prague, Czech Republic.I thank Slawomir Mazur (Warsaw, Poland), Alexey K. Tishechkin (Washington D.C., USA) and Lúcia M. Almeida (Curitiba, Brazil) who reviewed this manuscript and suggested numerous corrections.Special thanks to Harald Letsch, Editor at Deutsche Entomologische Zeitschrift for his valuable comments on the manuscript and editorial work.