Stenus (Nestus) melanopus
Creators: name: Ryvkin, Alexandr B.
Publisher: name: Zenodo
Year: 2012
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Stenus
Stenus melanopus

description: Stenus (Nestus) melanopus (Marsham, 1802)
(Fig. 7K)
Staphylinus melanopus Marsham, 1802: 528.
Stenus melanopus – Stephens 1829: 290. — Stephens 1833: 299. — Stephens 1839: 411. — Hardy 1851: 45. — Waterhouse & Janson 1855: 138, 151. — Rye 1864: 41. — Fauvel 1869: 492 (pars). — Rye 1870: 84. — Fauvel 1873: 256. — J. Sahlberg 1876: 59 (pars; original record: false). — Fauvel 1878: 102 (pars). — Fauvel 1886: 29. — Fowler 1888: 336 (pars). — J. Sahlberg 1900: 29 (false). — Fauvel 1902: 75 (pars). — Sainte-Claire Deville 1906: 82. — L. Benick 1921a: 144. — Wüsthoff 1934: Taf. II. — Normand 1935: 364. — L. Benick 1947: 90. — Focarile 1964: 63. — Puthz 1966: 146. — Puthz 1970b: 174, 178. — Puthz 1972e: 49. — Puthz 1973a: 26. — Anderson 1984: 247. — Lucht 1987: 96. — Puthz & Zanetti 1995: 18. — Herman 2001: 2278. — Monsevičius & Pankevičius 2001: 41. — Puthz 2008: 150.
Stenus melanopus <?!> – J. Sahlberg 1880: 78. — Heyden 1881: 78. — Poppius 1899: 39. — Iljin 1926: 225.
Stenus (Nestus) melanopus – Ganglbauer 1895: 576 (pars). — Jakobson 1909: 481 (pars). — Reitter 1909: 158 (pars). — Johansen 1914: 505. — L. Benick 1929: 44 (pars). — Tottenham 1954: 62. — Smetana 1959: 202. — Palm 1961: 88. — Szujecki 1961: 33. — Horion 1963: 339. — Scheerpeltz 1963: 417. — Lohse 1964: 116. — Puthz 1965: 27. — Puthz 1967c: 8. — Puthz 1967d: 305. — Puthz 1971a: 83, 97. — Puthz 1972a: 259. — Tichomirova 1973: 173. — Bordoni 1974: 13. — Dauphin 1993: 187 (pars). — Outerelo et al. 1995: 80. — Bordoni 2004: 119.
Stenus (s. str.) melanopus – Bernhauer & Schubert 1911: 162 (pars). — Scheerpeltz 1933: 1160. — Campbell & Davies 1991: 111.
<?> Stenus (Nestus) cribrellus Rey, 1884: 261.
<?> Stenus nitidus Lacordaire, 1835: 450.
<?> Stenus nitidus – Erichson 1840: 703. — Kiesenwetter 1845: 224. — Lucas 1846: 122. — Fairmaire & Laboulbène 1856: 576. — Kraatz 1857: 756. — Thomson 1857: 224. — Kraatz 1858: 123. — Thomson 1860: 225. — Seidlitz 1872 –1875(1874): 255. — Seidlitz 1887 –1891(1889): 365.
<?> Stenus (Nestus) nitidus – Rey 1884: 256.
<?> Stenus sulcicollis Stephens, 1833: 295 (nomen dubium).
Stenus tythus Schaufuss, 1882: 621.
Material examined
UK: Lectotype (designated herein): ♀, <small square of red paper>, ‘53’ <hand-written with black Indian ink on small white oval>, ‘ British Isles. J. Stephens Coll. BM 1853–46’ <printed rectangular label>, ‘Standing in Stephens Coll. as Stenus melanopus Marsham’ <printed rectangular label>, ‘LECTOTYPUS’ <my standard printed red label>, ‘LECTOTYPUS | Stenus | melanopus Marsham | A.B. Ryvkin des. 2003’ <my standard printed determinative label> (BM).
FRANCE: 1 ♀, ‘806’, ‘ Stenus | melanopus | Marsh. | Gallia’ [ex coll. Semenov-Tian-Shanskiy] (ZIN); 1 ♀, ‘ Corsica. 4121 [= Stenus melanopus Marsh.] – 2.’, ‘4121. melanopus Marsh. ’ (ZIN).
UKRAINE: 1 ♂, 3 ♀♀, Odessa Area, Bolgradskiy District, near Krinichnoye, fresh-water lake shore, in reed drift, 5 May 2003, A.V. Gontarenko leg. (AR).
ALGERIA: 1 ♂, ‘186’, ‘? Algeria |? Deyrolle.’ (ZIN).
Measurements of the lectotype
Entire body length: 3.1 mm; head width: 48; pronotum length: 45; pronotum width: 45; elytral length: 59; elytral length by the suture: 50; elytral width between humeri: 53; maximum elytral width (in posterior ¼): 64.
Remarks
The lectotype of S. melanopus is designated from among the four specimens under this name in Stephens’ collection and originating likely, at least in part, from Marsham’s collection. Only this female belongs to melanopus in the commonly accepted interpretation. Only this specimen has been marked with a small patch of red paper and only for this specimen is the number ‘53’ indicated, which corresponds to the number of the species in Stephens’ ‘Illustrations of British Entomology’; it is believed to have been placed by Waterhouse on a small white oval label, without additional daggers. I have transferred it to a new rectangular board; the old, smaller board remains on the same pin.
Similar problems that have arisen during the revision of the collections of Marsham, Kirby, and Stephens have been discussed many times by many authors (e.g. Tottenham 1937; Hammond 1972). An excellent historical reference was kindly compiled by Mrs. Sharon Shute (Department of Entomology, BM), in addition to the material received by me on loan in 2002. Below, I give a slightly abbreviated version of the text of this reference with the permission of the author and management of the Department [e-mail of February 20 2004]:
“ Stenus melanopus Marsham
This species was described by Marsham 1802. Stephens redescribes this species, in Illustrations of British Entomology […]. Stephens acquired specimens from Marsham’s collection when it was sold after his death and normally indicates in his text if he had a Marsham specimen. The species name in the Illustrations is attributed to Marsham, however, he does not mention that he had Marsham’s specimen. The Staphylinidae in the Stephens collection normally bear small, white, round labels if they come from the Marsham collection, (see Hammond 1972 […]). It is thought these were put on by Stephens, although they do not occur on the specimens of the species of many other families in his collection although we know from Stephens sale list of the Marsham collection that he did indeed purchase specimens of many of these species. The larger oval white labels with black ink numbers are (? Waterhouse) attached to all four specimens of this species in the Stephens collection. The numbers on these labels refers to the species number in The Illustrations Vol. v. there is no indication what the asterisks mean. None of these specimens have a Marsham round, white label, whereas other species within this genus do. This is a mystery because Waterhouse in his paper with Janson, on some of the British Stenus species, […], says that the ‘type’ is in the Stephens collection. This may have been an assumption on his part and he may not have known what the round, white labels meant. The fact that Stephens does not mention having Marsham’s specimen at the time of the redescription I think can be taken to assume he did not have it in his collection. Although the series label is not in his hand and could be Marsham’s ???. […] It may be advisable to select a neotype from the Stephens collection as without a label on the specimen it will not be possible to identify which if any of the four specimens came from the Marsham collection. Please note that as the specimens in the Stephens and Kirby collections do not have any locality data it is not possible to tell if the specimens are those he had in front of him at the time of his descriptions or later additions. It is known that he exchanged material and often disposed of specimens if he collected ‘better’ ones which is why in a number of cases it has been found that the specimens standing as a particular species in Stephens collections do not fit his description. Care must be taken when using these specimens to ‘fix’ names, to take account of common usage of names and the common interpretations of such species before changing names as a result of examining Stephens specimens, which should in every case be carefully checked against Stephen’s description. […]” [e-mail of May 16 2002]
Unfortunately, Marsham's original description cannot help sufficiently with identification of the original type specimen: ‘St. niger obscurus scaber, pedibus concoloribus. Long. corp. 1½ lin. Habitat -----. Descr. Simillimus St. immuni, at pedes omnino nigri.’ Every third Stenus species appears to conform to the diagnosis cited. Even the reference to S. immunis, described by Marsham in the same monograph, can add little clarity to solving this problem. The latter name, having been synonymized with no evident
proof with either S. (Nestus) circularis Gravenhorst, 1802 or S. (Hemistenus) pallipes Gravenhorst, 1806, at different times, requires a separate revision in itself.
The redescription by Stephens (1833), on the contrary, is much more detailed and corresponds well, in main features, to the melanopus in commonly accepted interpretation. The only inconsistency may be found in the coloration of the maxillar palpi: ‘antennae and palpi black, immaculate’ whereas the basal segment of the palpi is in fact yellow. The following information provides an explanation for this inconsistency: ‘It is said of Stephens that he declined to use a microscope regularly believing that what could not be seen with the naked eye was not worth studying’ (Darby 2010). I can confirm that the colour of the basal segment of the palpi may be poorly visible in a total specimen even at a high magnification. The redescription given by Waterhouse & Janson (1855) ‘according to the type specimen in Stephens’ Coll.’ relates undoubtedly to S. melanopus in commonly accepted interpretation and conforms to the unique female mentioned above. It is necessary to remember that the paper by Waterhouse & Janson (1855) was published just about three years after the death of Stephens, by authors who had been close to him and had known his collection for many years. Thus, both the redescriptions obviously indicate that Stephens had at least a specimen of the ‘true’ melanopus in front of him at the time of his redescription.
I suppose ‘the label problem’ to be confused in this case not so far as the author of the aforementioned historical reference finds. Waterhouse & Janson (1855) reported that ‘the specimens which Mr. Stephens used to call his ‘ Type specimens ’ are almost always marked by some kind of ticket attached to the pin holding the insect. The Marshamian specimens are thus marked by a round yellow ticket; and when the species is described in the ‘ Entomologia Britannica ’, a number will be found on the under side of the ticket, corresponding to the number of the species in that work. Other type specimens are either marked by a round white ticket without a number, or by a small square ticket with a number. Mr. Stephens’ own species are not marked’. I should like to stress the words ‘almost always’ in the text cited. In my opinion, they may prove that not all the ‘ type specimens’ in the collection were actually marked in the way they described. About the small round labels Hammond (1972) mentions: ‘All internal evidence from the collection suggests that the colour of these labels is of no great significance but that they all indicate specimens originating from Marsham’s collection’; however, he did not present valid arguments against the possibility that specimens without such round tickets or having labels of other shapes may also have belonged to the named collection. The same author further stated: ‘The significance of certain other labels attached to various specimens, including white rectangles bearing a number and small red squares of paper, has not been discovered’; however, these ‘white rectangles’ may have conformed to the ‘small square tickets with a number’ in the aforecited fragment by Waterhouse & Janson (1855). Apropos, the latter authors did not indicate a colour of the ‘tickets’, and the small red squares of paper may be analogs of the white rectangles: as we can see in the text, Waterhouse & Janson did not regard the numbers as indispensable attributes of the type labels.
Stephens never stated that all the material from Marsham’s collection would be specified separately in his ‘Illustrations’. Indeed, he mentioned such material directly in the Stenus section in the following three cases:
1. under S. marshami Stephens, 1833 (= S. (Tesnus) brunnipes Stephens, 1833; = S. immunis Marsham, 1802, pars); it was, at least in part, based on material in the series of immunis from Marsham’s collection (see the ‘Systematic Catalogue’: Stephens 1929: 289);
2. under S. immunis Marsham, 1802 (the name requires a revision, see above); since the series proved to be heterogeneous, it was reasonable to show that a part of the original series remained under the name of immunis; besides, since Marsham’s descriptions did not contain precise references to localities, Stephens gave additional data (London & Norfolk), having mentioned that his own specimens came ‘from the Marshamian collection’;
3. under S. laevis Stephens, 1833 (= S. (Metatesnus) pubescens Stephens, 1833), which he attributed to Marsham and therefore, to explain the posthumous attribution, found it appropriate to mention that his specimen had been ‘obtained from the Marshamian cabinet’.
However, I can find no reasons for particularly citing material from Marsham's cabinet under the name melanopus: the species was thoroughly described and published by Marsham. It was a well known fact that Stephens had purchased Marsham’s collection. In this case, Stephens merely gave the redescription more detailed based on the ‘ type specimen’ and then added: ‘Also found, not uncommonly, within the metropolitan district and in Norfolk’, with a reference to the habitat data provided by L. W. Dillwyn, Esq. The word ‘also’ here means, in my opinion, that the above redescription is based on Marsham’s original material.
Based on the statement by Waterhouse & Janson (1855), as well as on all the facts aforesaid, I consider the specimen under discussion to be an original type specimen that can be designated as the lectotype.
The remaining three specimens (1 ♀ of Stenus (Tesnus) brunnipes Stephens, 1833; 1 ♂, 1 ♀ of Stenus (Nestus) boops Ljungh, 1810) have not been marked as paralectotypes inasmuch as their belonging to the original type series seems improbable; all those have been supplied with my common determinative labels. Each of these specimens has also been labelled by Waterhouse: ‘The species follow in succession, in the cabinet, in accordance with the descriptions in the “ Illustrations,” but in one or two instances there have undoubtedly been some accidental transpositions; and to prevent further changes of this nature, all the species, and indeed nearly all the specimens, have now been numbered to correspond with the numbers of the species as given in the “Manual.” [= Stephens 1839]. The numbers here alluded to are on small oval tickets attached to the specimens […]’ (Waterhouse & Janson 1855). Besides the number ‘53’, the oval individual labels bear additional markings: one dagger under S. brunnipes; two daggers (one under another) under each of the specimens of S. boops. The daggers may have marked extraneous species within each series.
In different times different species have been erroneously synonymized with S. melanopus: S. (N.) capitatus Eppelsheim, 1878 (Fauvel 1878, 1902; Fowler 1888; Ganglbauer 1895; Reitter 1909), S. (N.) discretus Rey, 1884 (now a synonym of S. (N.) crassus Stephens, 1833) (Ganglbauer 1895; Fauvel 1902; Reitter 1909; Bernhauer & Schubert 1911; L. Benick 1929; Dauphin 1993), S. (N.) ignotus Eppelsheim, 1890 (Fauvel 1902), S. (N.) piscator Saulcy, 1864 (Fauvel 1902), S. (N.) arctulus Hochhuth, 1849 (now a synonym of S. (N.) incanus Erichson, 1839) (Fauvel 1902), S. (N.) morulus Baudi, 1870 (now a synonym of S. (N.) piscator Saulcy, 1864) (Fauvel 1902) and S. (N.) sulcifrons Eppelsheim, 1878 (now a synonym of S. (N.) piscator Saulcy, 1864) (Fauvel 1902). Among the names having been regarded as synonyms of S. melanopus till now, only S. tythus Schaufuss, 1882 does not raise doubts: its female type was studied and identified as melanopus by Puthz (1967c). None of the names S. cribrellus Rey, 1884, S. nitidus Lacordaire, 1835 or S. sulcicollis Stephens, 1833 have been revised based on the type material.
The last of these seems to be a nomen dubium. Waterhouse & Janson (1855: 148-149) indicated: ‘The detailed description in this work is possibly from a small specimen of St. [(Hemistenus)] subaeneus, Er. The insect in Mr. Stephens’ cabinet which stands for sulcicollis evidently is misplaced by a black-legged species, i.e. St. melanopus, of Marsham’. The result of this mess was marked well by Rye (1870): ‘This [sulcicollis] and the preceding [assimilis] are given as valid species in Gemm.[inger] & v. Harold’s Cat.[alogue], ii, though (? because) they are not recognizable or known to British Entomologists. The former is represented by brunnipes, and the latter by melanopus, in Stephens’ collection. See Wat. & Janson ([…] 1855), from whose account of the confusion with regard to these insects it is evidently impossible to do anything but ignore them altogether.’ Fauvel (1869), without any explanation, put the name sulcicollis in the synonymy of melanopus. The assumption by Puthz (2008) that Fauvel had seen the ‘type’ in Stephens’ collection before synonymizing sulcicollis (‘FAUVEL hat das 1869 wohl ebenso gesehen, sonst hätte er seine Synonymie nicht ausgesprochen’) is contrary to fact: unlike many other names, which are supplied with remarks ‘ex typ.’ in the paper cited, the pair ‘ S. sulcicollis Steph. = S. melanopus Marsh. ’ has no such remark. In addition, the reference by Puthz (2008) to the ‘indisputable authority’ of Fauvel, who actually had the name of ‘master of false synonymy’ (Lohse 1985; see, for example, the list of erroneous synonyms above) seems not to be the best way to confirm ‘ausgesprochene Synonymie.’ By the way, in the later work (1873), Fauvel himself discussed the problem much more deliberately, with a reference to Rye (1870): ‘Le sulcicollis Steph. (Ill. Brit., V, 295), représenté dans la collection Stephens par le melanopus, est une espèce méconnaissable à rayer des catalogues (V, Rye, Ent. Annual, 1870, 84)’. Bernhauer & Schubert (1911), based on the original description, placed S. sulcicollis within the subgenus Hemistenus Motschulsky, 1860 (s.l.) as a valid species. Thus, I find the synonymy of S. sulcicollis with S. melanopus to be ill-founded.
The original descriptions of both S. cribrellus and S. nitidus correspond rather to species of the atratulus complex than to S. melanopus: ‘un exemplaire [...] à prothorax paraissant un peu plus court, subtransverse, avec une fossette poncti-forme, obsolète, seulement visible suivant un certain jour et située près de la base [...]’ (Rey 1884); ‘Prothorax un peu plus long que large, [...] avec une fossette oblongue peu marquée sur le disque [...]’ (Lacordaire 1835). It is obvious that the small ‘fossette ponctiforme, obsolète’ as well as ‘fossette oblongue peu marquée’ cannot conform with the long and deep furrow on the pronotum in S. melanopus. Therefore, most subsequent records of S. nitidus may have been the result of misidentification of S. melanopus. Thus, S. tythus may be regarded as the only reliably established synonym of S. melanopus.
This species, widely distributed over the Mediterranean, W & C Europe, and also introduced into the Nearctic (see Puthz 1966; Campbell & Davies 1991), is rather variable and similar to many other representatives of different groups in many characters; therefore the range: ‘Mittel-Südeuropa, südliches Nordeuropa, Nordafrika, Kanaren, Kleinasien, Westsibirien, östliches Nordamerika’ (Puthz 1971a, 1972), seems to be greatly exaggerated. J. Sahlberg (1876) first recorded S. melanopus for S Finland (‘Sällsynt; funnen några gånger invid Åbo af O.Reuter, och förf.[attare]’). The same data (‘Regio Aboënsis’) was cited by him in the subsequent Catalogue (J. Sahlberg 1900). Although L. Benick (1921a) ascertained that this record had resulted from misidentification (‘Ein von Sahlberg […] genanntes Stück (Reuter, Åbo) in der Sammlung des Mus. Hels. (‘Reuter, Pargas’) ist atratulus Er.’), many subsequent authors continued to cite Finland in the range description of melanopus (Palm 1961; Horion 1963; etc). Benick (l.c.) soundly questioned also the record by Poppius (1899: ‘statsradet A. Günther [...] i trakten kring Petrosawodsk’) for N European Russia (‘Die Angabe von Poppius, nach der die Art in Russ. Karelien […] vorkommen soll, ist nachzuprüfen’). In his well-known work on Siberian Coleoptera, J. Sahlberg (1880) found S. melanopus to be distributed over the Ob’ basin (‘In territorio silvoso prope oppidum Tobolsk 3/6 unicum specimen invenit Bergroth’). This misleading record was repeated by Heyden (1881) and became a source of erroneous citation of this species for W Siberia by many authors up to present time (Jakobson 1909; L. Benick 1929; Scheerpeltz 1933; Smetana 1959; Szujecki 1961; Horion 1963; Puthz 1971a, 1972; Tichomirova 1973; Dauphin 1993). Neither Puthz (pers. comm.) nor I have seen melanopus specimens from territories eastwards of Denmark and southernmost Sweden. One can confidently suppose the N Russian and Siberian records to relate to another species; most likely, it may be a species of the canaliculatus group, either S. labilis or S. confusus.
The record for Yekaterinoslav [=Dnepropetrovsk] of the Ukraine (Iljin 1926) may also be a result of misidentification. The only material I have seen from the territory of the former USSR is given in the Material section (see above: Odessa Area). The recent record of this species for Lithuania (Monsevičius & Pankevičius 2001: 1 specimen of undisclosed sex) requires confirmation.
The bionomics of this species seem to be rather diverse. Along with different open alluvia: seashore, riverside, and lakeside (Hardy 1851; Rye 1864; Fauvel 1873; Fowler 1888; Johansen 1914; L. Benick 1929, 1947; Palm 1961; Horion 1963; Anderson 1984; Dauphin 1993), many other types of habitats have been reported: hay-stack rubbish (Rye 1864), manure heaps (Tottenham, 1954), dry manure (Dauphin 1993), compost heaps (Anderson 1984), detritus (Smetana 1959; Dauphin 1993), humus (Bordoni 1974) and bogs, including peat and Sphagnum (Horion 1963).
The suppositions of halophily for S. melanopus (L. Benick 1947; Puthz 1965, 1971, 1972) seem to be ill-founded, inasmuch as inhabiting seashore alluvia and lakesides of brackish basins is not a sufficient ground to consider a species to be halophilous. The idea was argued and rejected by Horion (l.c.: ‘Von einer allgemeinen Halophilie dieser Art kann keine Rede sein’). I believe that the fact that S. melanopus inhabits Sphagnum bogs is quite enough for the assumption of halophily to be denied.
As to the records of the occurrence of this species in manure and compost heaps, I should like to note that those habitats are common shelters which many Stenus species use during adverse weather or in adverse seasons.
description: Published as part of Ryvkin, Alexandr B., 2012, New species and records of Stenus (Nestus) of the canaliculatus group, with the erection of a new species group (Insecta: Coleoptera: Staphylinidae: Steninae), pp. 1-62 in European Journal of Taxonomy 13 on pages 44-50, DOI: 10.5852/ejt.2012.13, http://zenodo.org/record/3857775