Scopaeus

Herman, Lee, 2023, Generic Revisions Of The Scopaeina And The Sphaeronina (Coleoptera: Staphylinidae: Paederinae: Lathrobiini), Bulletin of the American Museum of Natural History 2023 (460), pp. 1-195 : 67-73

— Coiffait, 1984: 148 (subgenus of Scopaeus ; key to species). — Outerelo and Gamarra, 1985: 36 (characters). — Frisch, Burckhardt, and Wolters, 2002a: 46 (synonym of Scopaeus ; type species). — Frisch, Burckhardt, and Wolters, 2002b: 2 (synonym of Scopaeus ). — Smetana, 2004: 615 (synonym of Scopaeus ).

Anomoscopaeus Coiffait, 1968: 426 . Type species: Xantholinus gracilis ( Sperk, 1835: 152) , fixed by original designation.

— Coiffait, 1984: 148 (subgenus of Scopaeus ; key to species). — Outerelo and Gamarra, 1985: 36 (synonym of Heteroscopaeus ).

— Frisch, Burckhardt, and Wolters, 2002a: 46 (synonym of Scopaeus ; type species).

— Frisch, Burckhardt, and Wolters, 2002b: 2 (synonym of Scopaeus ). — Smetana, 2004: 615 (synonym of Scopaeus ).

Asiascopaeus Coiffait, 1984: 152 . Type species: Scopaeus asiaticus Bernhauer, 1915: 265 , fixed by original designation.

— Smetana, 2004: 615 (subgenus of Scopaeus ; Palaearctic catalog). — Frisch, 2015a: 139 (synonym of Scopaeus ).

Typhloscopaeus Jarrige, 1951: 333. (Described as a subgenus of Scopaeus ; Incertae sedis). Type species: Scopaeus pauliani Jarrige, 1951: 333 , fixed by original designation and monotypy. [Note: The status of this name is discussed below under “Synonymy”.]

DIAGNOSIS: Unique to Scopaeus are a metathoracic/mesofemoral stridulum (figs. 119, 121) and the long, tapered, apically acute, metakatepisternal processes (figs. 83, 97, 110) extending between the metacoxae; these two features separate the genus from all other Scopaeina and Paederinae . The stridular file is on the lateral (figs. 102, 104, 105) or submarginal (figs. 114, 119, 154, 155) surface of the metaventrite; the stridular plectral ridges (figs. 85, 106, 121) are on the mesial base of the mesofemur. Other scopaeine genera lack a stridulum and the metakatepisternal process is short and rounded or diagonally truncate apically (figs. 241, 270, 300, 334), not long and acute. An outlier of Scopaeus with respect to the metakatepisternal processes is S. filiformis for which the processes are similar to those of species of Micranops (cf. figs. 89, 270); the former has a stridulum, that is, a file and plectral ridges (figs. 90, 92), the latter does not (figs. 270, 271, 277); the two also differ by the position of their trichobothrium. The metakatepisternal process is more easily seen than is the stridulum, therefore more accessible for identification, but must be used with caution for species such as S. filiformis but is easily put aside by the position of the trichobothrium. The metakatepisternal process of S. filiformis (figs. 89, 94), unlike other species of the S. debilis species group, is short, the lateral margin extends diagonally to an acute apex and has a subapical notch. That notch is absent from the similar metakatepisternal processes of Micranops (figs. 270, 280).

Ancillary characters aid in separating Scopaeus from others of the subtribe.

The slender, constricted neck of Scopaeus (figs. 7, 47, 49, 99, 161, 205) will separate it from Trisunius (figs. 258, 342), most species of Orus (fig. 257), and the Western Hemisphere species of Micranops (fig. 256). The neck/head width ratio of Scopaeus is one sixth to one quarter as wide as the head; for Orus and the Eastern Hemisphere species of Micranops is it about one fifth to two fifths, and for Hyperscopaeus it is one eighth to one sixth. So, there is a small overlap among some species of these genera with species of Scopaeus . The position of the trichobothrium differs among Orus , Micranops , and Scopaeus . For Orus (figs. 297, 315) the trichobothrium is in a long canal beginning at the posterodorsal edge of the tapered eye, whereas that of Micranops (figs. 267, 282) is in a short, deep cavity behind and separated from the margin of the eye. The trichobothrium of Hyperscopaeus (fig. 245), Scopaeus (figs. 15, 26, 39, 206), and Trisunius (fig. 274) is above and contiguous with and near the middle of the dorsal edge of the eye.

The gular sutures of Hyperscopaeus (fig. 244) are narrowly separated. For most Scopaeus (figs. 47, 48, 50) the sutures are moderately widely separated or narrowly so in some (fig. 49).

The dorsal surface of the aedeagal median lobe of Scopaeus is sclerotized (fig. 158) and the midlongitudinal surface is fused for the entire length; the whole length of the sclerotized dorsal surface of the median lobe of Hyperscopaeus is divided by a median membranous strip (fig. 243).

Tergite IX of Scopaeus males (figs. 72, 74, 76), unlike that of the other genera of the Scopaeina , is symmetrical. For Hyperscopaeus , Orus (figs. 292, 323), and Trisunius (fig. 331) tergite IX is notably asymmetrical; the left anteroventral side is larger, more broadly rounded, and wraps medially more than does the right anteroventral side. Micranops differs from the preceding three genera in that the left anteroventral side is only slightly larger than the right (fig. 261).

DESCRIPTION: Body length 1.9–4.9 mm.

Head (figs. 1–5, 7, 8) with postocular lateral margin broadly rounded; basal angles distinct and well developed to absent; basal margin broadly and shallowly to moderately emarginate, to truncate, to rounded and continuous with gradually and broadly rounded lateral margins; basal margin without median tumescence; basal margin with or without shallow, vertical sulcus; posteroventral surface without small to minute tubercle laterad of neck.

Neck petiolate (figs. 1–5, 7, 99); nuchal groove deep and strongly constricted, and base of neck abruptly expanded (figs. 99, 161, 205); neck width across nuchal constriction one sixth to one fourth as wide as greatest postocular width of head; nuchal ridge present dorsally and laterally (figs. 161, 193).

Dorsal cephalic surface with dense, minute to fine to moderately strong to coarse, setate punctation (most species) or dense, strong, setate, reticulo-umbilicate punctation (some species; fig. 193) or dense, setate, micropunctate microtubercles (some species), or much less dense, hardly discernible, setate punctation (some species); surface with (most species) or without (some species) interpunctational microsculpturing; surface with dull shine (most species) or polished (some species); pubescence (fine setae) dense (most species) to sparse (some species) dorsally and laterally, less dense ventrally; macrosetae short to long, sparsely distributed, frequently present peripherally, present dorsally in some species.

Cephalic trichobothrium near midpoint of dorsal margin of eye (figs. 15, 26, 39, 205, 206); bothrium in rounded to moderately elongated depression (figs. 14, 15, 23, 39, 40); surface near depression with setae, particularly dorsad of depression (figs. 14, 15, 23, 40).

Eyes with posterior margin broadly rounded; corneal lenses without sensilla (figs. 23–46); corneal lens with smooth (figs. 24, 26, 31–33, 36, 39, 42, 43–45), slightly to strongly wrinkled (figs. 27, 29, 30, 34, 35, 37, 38, 40,46) or slightly altered surface (figs. 23, 25, 41).

Gular sutures moderately widely (most species) (figs. 47, 48, 50, [99, 161 sutures visible through the cuticle as shadows]) to narrowly (fig. 49) separated.

Mandibles, denticular number: left/right respectively, 1/3, 2/2, 2/3, 3/3, or 3/4 (figs. 61–71).

Labrum quadridentate (figs. 6, 100, 169, 186) for most species, edentate (fig. 59), unidentate (fig. 58) or bidentate (fig. 159) for some.

Pronotum broadly and shallowly to moderately strongly convex (figs. 1–5, 8, 52, 54, 56); surface with dense, minute to fine to moderately strong to coarse, setate punctation (most species) or dense, strong, setate, reticulo-umbilicate punctation (some species, fig. 193) or dense, setate, micropunctate microtubercles (some species), or much less dense, hardly discernible, setate punctation (some species); surface with (most species) or without (some species) interpunctational microsculpturing; midlongitudinal strip with or without punctation and with (most species) or without microsculpturing (some species); surface with dull shine (most species) or polished (some species); pubescence of fine setae dense to sparse dorsally and laterally, less dense ventrally; macrosetae short to long, sparsely distributed, frequently present peripherally, present dorsally in some species; median groove absent or absent medially, but present and shallow anteriorly and posteriorly or posteriorly only; posterior median groove of some species replaced by slightly raised ridge.

Prohypomeron with postprocoxal lobe separated from remainder of hypomeron by prohypomeronal transverse ridge (fig. 52) or transverse ridge absent (figs. 54, 56); prohypomeronal submarginal ridge present (figs. 52, 54) or absent (fig. 56); lobe with or without setae. Notosternal suture present (figs. 51–54), absent (figs. 55, 56), or partially developed (fig. 57).

Elytra longer to shorter than pronotum; surface with dense microtuberculation or with dense to sparse punctation; pubescence dense to sparse; posterior edge with or without row of setae.

Mesoventrite with large, deep, oval to rounded, median depression (figs. 82, 93, 176); surface entirely or partially covered with reticulate microsculpturing (figs. 93, 109, 122, 141, 166, 188, 198).

Mesofurcasternum with (fig. 82) or without (figs. 103, 122) internal, furcasternal apophysis on posteromedial margin.

Mesofemur with one to at least 12 plectral ridges at basal of posterior (mesial) surface usually nearer dorsal than ventral edge (figs. 85, 92, 106, 113, 121, 132, 139, 144, 185, 191, 197, 203).

Mesocoxal acetabulum margined anterolaterally by short (figs. 114, 195, 201, 213), moderately long (figs. 110, 125, 131, 137), to long (figs. 101, 104, 149) pericoxal ridge or without ridge (figs. 83, 177).

Metaventrite with stridular file (figs. 104, 105, 119, 133, 155, 165); file extending posteriorly from near mesocoxa and parallel to submarginal ridge (figs. 104, 105, 172, 173) or parallel to submarginal ridge anteriorly and diverging and increasingly separated from ridge posteriorly (figs. 119, 195, 165); submarginal ridge parallel to or slightly diverging from dorsolateral margin of metaventrite or gradually curved medially near middle then bent abruptly and curved to become parallel to dorsal margin again in some species (figs. 119, 165, 188).

Metakatepisternal process long, slender, and apically tapered to acute point (figs. 97, 154, 183) or short and broad with lateral margin approaching median margin diagonally to apical point; diagonal margin notched near apex (figs. 89, 94).

Sternite II with anterior margin bisinuate (figs. 167, 179, 215); median point of posterior margin present (figs. 116, 145, 167, 179) or absent (figs. 86, 128); median ridge present (figs. 116, 145, 179 215).

Sternite III with (figs. 179, 204) or without (figs. 147, 192) intercoxal carina; intercoxal carina long (fig. 179), short (fig. 86, 140), or reduced to median point extending from transverse basal ridge (fig. 91, 128, 145); transverse basal ridge strongly (fig. 192, 204), moderately (figs. 140, 215), or subtly bisinuate (fig. 86).

Sternite IV with small (figs. 87–88, 134–135, 152–153, 199–200) to large (fig. 123), apparently, glandular pore near anterior margin or pore apparently absent (figs. 129–130, 216); depression present (figs. 87–88, 129–130, 134–135) or absent (figs. 199–200, 232–233) (depression might be an artifact; see more above in section on morphology of the Scopaeina ).

MALE: Sternite VII unmodified or with variously emargination of posterior margin, depressions of surface, and clusters of macrosetae.

Sternite VIII with wide to narrow, deep to shallow median, variously configured emargination of posterior margin and with or without median extension or teeth.

Tergite IX symmetrical: left and right anteroventral sides of approximately equal size and form (figs. 72, 74, 76); base fused (figs. 72, 76) with medial incision or separated (fig. 74) into right and left portions of tergite IX.

Tergite X (see Frisch, 2002: figs. 40–44) elongate, ovoid or pentagonoid; anterior margin rounded with slight to distinct apically rounded, median point (figs. 72, 74, 76).

Aedeagus with dorsal surface of median lobe fully sclerotized, without midlongitudinal membranous split (fig. 158); parameres present as tiny lobes appressed to surface on each lateral side of median foramen.

FEMALE: Sternite VII with unmodified posterior margin.

Sternite VIII with rounded posterior margin.

Tergite IX symmetrical (figs. 73, 75, 77): left and right anteroventral sides of approximately equal size and form; middorsal base fused with median incision extending anteriorly from posterior margin (figs. 73, 77) or entirely divided medially (figs. 75).

Tergite X (figs. 73–75) long, ovoid, and anteriorly tapered with rounded anterior margin; anterior margin with or without rounded median point.

Spermatheca bipartite with elongate extension/process of hollow chamber segment (see Frisch et al., 2002a: 30, figs. 22–29).

DISTRIBUTION AND HABITAT: The species of Scopaeus are widely distributed in temperate, subtropical, and tropical regions throughout the world but most species occur in subtropical and tropical areas and have been collected at 150 meters below sea level in Sri Lanka (label data from specimens in AMNH) to as high as 3500 meters, for S. likovskyi , in Afghanistan ( Frisch, 2008a: 283). The genus remains unknown from arctic or subarctic regions or very high elevations.

Frisch et al. (2002a: 28), wrote that most species are found under stones, in gravel on damp sandy shores of rivers and streams that are more or less sunny, sparsely vegetated, with ground litter and other organic debris. They are not found in wet gravel that lacks vegetation or organic debris near the shoreline. Species frequently colonized narrow banks or larger banks if the conditions are appropriate. Some species live in marshy habitats such as wet meadows, bogs, and swamps and some are found in barrens, grasslands, even dry grasslands, and forest steppes.

In accordance with the observations and experience of Frisch, label data show that most specimens collected by others were found in litter at the edge of gravelly and sandy rivers, streams, and seeps. In Zimbabwe specimens were taken from marshy ground near streams, marshy turf near or separated from streams. In some instances, in Vietnam, for example, Scopaeus were found even when the streams were reduced to mere trickles or reduced to scattered drying pools and puddles, lined with abundant organic debris along the edges (also seen commonly by Frisch, personal commun.). Although in more moist regions increasingly fewer specimens and decreasing species diversity are probable as one moves farther from the preferred habitat of Scopaeus spp. along streams and rivers, in arid/semiarid regions specimens are found only near stream, lakes, and other moist areas.

However, labels for specimens collected in moist regions record specimens from deep forests in damp depressions, from under the barks of logs, in log mold, epiphytic debris, moss, humus, litter under ferns, moss near cascading streams, tree-fall and fruit-fall litter, and decaying leaves or fruit. It is possible, perhaps likely, that many of these records are the result of sifting litter and debris thereby making the actual habitat difficult to discern and Frisch (personal commun.) regards such records as atypical for Scopaeus . Moreover, specimen number and species diversity rapidly diminish as one moves further from streamside habitats. Species and many specimens have been collected at lights and flight intercept and malaise traps; these collections simply indicate the presence of the species and that they can fly.

Nothing is known of the feeding habits of Scopaeus species nor have their larval or pupal stages been described ( Frisch et al., 2002a), but they probably eat smaller arthropods, and their small size suggests they may eat eggs, small immature stages, and small non-arthropods.

SYNONYMY: Historical and new. Because Scopaeus is so speciose and so many modifications of the infrageneric classification have been published, particularly in the past 50 years, it seems befitting to summarize the historical synonymy and discuss the newly recognized ones.

Erichson (1840: 604) described Scopaeus to include four European, one North African, one Nearctic, and three Neotropical species. Two of the European species, Paederus laevigatus Gyllenhal and Lathrobrium minimus Erichson , were already known.

Polyodontus Solier (1849: 310 , 311), a junior homonym, was described for one, presumably Chilean species, P. angustatus , though no locality was cited nor was the number of specimens examined stated. Kraatz (1857: 701) combined the name with Scopaeus , perhaps because, according to the original description of Polyodontus , the “lengüeta” [tongue = labium?] is tridentate as is the ligular margin of Scopaeus . Whether Kraatz saw a type of Polyodontus is uncertain. After Kraatz moved Polyodontus to Scopaeus subsequent authors considered it to be either a synonym or subgenus. As a subgenus most of the species placed in Polyodontus were European or Eurasian along with one from New Zealand. The location of the type specimen(s) of P. angustatus is currently unclear; it was not found in Paris and a specimen labelled as “ type ” in Brussels is almost certainly not part of the type series. It is unknown which, if any, investigators who used Polyodontus for European species examined specimens of the original series (see Mulsant and Rey, 1878: 194; Ganglbauer, 1895: 529; Binaghi, 1935: 95–107; Coiffait, 1952: 8). The name was not used after 1952.

Motschulsky (1858: 641) proposed Scoponeus for one Asian species; without comment; Gemminger and Harold (1868: 618) synonymized the name with Scopaeus .

Casey (1886b: 220) named two genera. The first, Scopaeodera, was named for a North American species he transferred from Echiaster . He wrote that the genus would perhaps include some of Sharp’s South American species and his “Group 4” of the Central American species, together with S. pulchellus Erichson. However , only Echiaster nitidus LeConte was an originally included in the genus because Casey’s use of “perhaps” lends doubt to the inclusion of the others. Scopaeodera was cited previously as a junior synonym of Scopaeus in at least two publications and as a subgenus in others (see synonymic list for Scopaeus ). The placement herein as a junior synonym is a revised status for the name.

The second genus, Leptorus, Casey (1886b: 220) included 13 North American species. Later Casey (1905: 203) revised his opinion and synonymized Leptorus with Scopaeus because his renewed scrutiny of the European species of Scopaeus led him to conclude he was unable to find characters of sufficient importance or consistency to separate the two faunas.

In the same publication Casey (1905: 222, 214) named two more genera for American species, Scopaeopsis and Scopaeoma. Without stated reasons, those two genera, along with Scopaeodera, were reduced to subgenera ( Bernhauer and Schubert, 1912: 245; Blackwelder, 1939a: 100, 106) or junior synonyms ( Cameron, 1931: 169) of Scopaeus and have been listed as subgenera by many other authors (see synonymic list for Scopaeus ). In the present work both Scopaeopsis and Scopaeoma are revised status junior synonyms of Scopaeus .

Pseudorus , proposed for three American species ( Casey (1910: 190) was reduced to a subgenus ( Scheerpeltz, 1933: 1264), then a junior synonym ( Blackwelder, 1939a: 119) of Scopaeus ; both demotions were made without comment.

Coiffait (1952: 6; 1960: 285) described two subgenera, Stilpon and Euscopaeus , both junior homonyms, that he later replaced with Geoscopaeus and Alloscopaeus respectively ( Coiffait (1960: 284; 1968: 414). Along with the replacement names Coiffait (1960: 284, 285; 1968: 426; 1984: 150) established five more subgenera for Scopaeus : Heteroscopaeus , Hyposcopaeus , Anomoscopaeus , Asiascopaeus , and Hyperscopaeus .

Jarrige (1951: 333) described a new subgenus, Typhloscopaeus, for one specimen of a Madagascan species. See below for details of its disposition as a name of unknown placement.

By 2001 Scopaeus had grown from nine species in 1840 to over 400 distributed among 12 subgenera. However, that division was massively lopsided; the vast bulk of the species remained in the nominate subgenus, rather few were assigned to other subgenera. That disparity suggested Scopaeus s.s., that is without the subgenera, was likely to be a paraphyletic group; although the other subgenera were separated by denoted characters, none were proposed to support definition of the nominate group. In a landmark publication ( Frisch et al., 2002a) for the genus most of the Eurasian subgenera were regarded by the authors as polyphyletic and synonymized with Scopaeus (s.l.) and a classification of species groups, complementing those of Fagel (1973), was established. The subgenera Geoscopaeus , Alloscopaeus , Heteroscopaeus , Hyposcopaeus , Anomoscopaeus and later, Asiascopaeus , were synonymized with Scopaeus ( Frisch et al., 2002a: 46; Frisch, 2015a: 139, 146).

Among the remaining subgenera were the American Scopaeodera Casey, 1886, Scopaeoma Casey, 1905, and Scopaeopsis Casey, 1905, the Madagascan Typhloscopaeus Jarrige, 1951, and the African, Asian, and Australian Hyperscopaeus Coiffait, 1984 . Whether or not these names represented monophyletic groups, their valid status clearly rendered Scopaeus either polyphyletic, paraphyletic, or both.

Frisch steadfastly maintained in publication, correspondence, and in person that Hyperscopaeus should be separated from Scopaeus ( Frisch et al., 2002a: 38, 45; personal commun.). His opinion was based on derived external, aedeagal, and spermathecal features of Hyperscopaeus that separated it from Scopaeus and the derived characters that supported the monophyly of Scopaeus ( Frisch et al., 2002a: 38) . Most of the characters used to support this contention were genitalic features of the males and females that seemed difficult to access or understand or seemed not very strong. Nonetheless, his careful work and informed opinion created a strong incentive to painstakingly study the intersection of the two groups. I feared removing Hyperscopaeus would render Scopaeus paraphyletic and so continued searching both groups for other characters that might either support or refute Frisch’s hypothesis. In the end his contention was well supported, but with more accessible, new characters, and Hyperscopaeus is elevated to genus in the present work (see Discussion for Hyperscopaeus for a more complete explanation).

Typhloscopaeus was originally published as a subgenus of Scopaeus for one species, Scopaeus (Typhloscopaeus) pauliani , represented by a single female from Madagascar ( Jarrige, 1951: 333). None of the characters included in the description either persuasively support its assignment to or exclude it from Scopaeus or the Scopaeina , so, I think there is no supportable reason for removing it or doing anything more than recognizing its indeterminate status as incertae sedis and leaving it where it is and as it was originally added to Scopaeus until the type can be studied. According to the description ( Jarrige, 1951: 333), the unique type specimen was deposited in the Muséum National d’Histoire Naturelle, Paris. The specimen was not found by curator Azadeh Taghavian-Azari after an extensive search of the Jarrige and the general collections.

Finally, remaining are the American Scopaeodera Casey, 1886, Scopaeoma Casey, 1905, and Scopaeopsis Casey, 1905, described as genera and reduced to subgenera ( Bernhauer and Schubert, 1912: 245; Blackwelder, 1939a: 100, 106; Newton et al., 2000: 386; Navarrete-Heredia et al., 2002: 280) or synonyms ( Cameron, 1931: 169) of Scopaeus . Along with these three names two others recognized as genera for American species, Scopaeomerus Sharp (1886: 538) and Euscopaeus Sharp (1886: 548) , are added to Scopaeus as species groups in the present work. Among these five groups Euscopaeus and Scopaeopsis are indistinguishable; they were never compared with each other until now. The species of Euscopaeus-Scopaeopsis are among the largest of Scopaeus , the head, pronotum, and elytra are coated with dense, fine pubescence and lack or have few macrosetae (fig. 5). The integument of the species of Scopaeodera is polished, the pubescence is sparse, macrosetae are notable, and the prothorax is more or less ovoid (fig. 3). Scopaeomerus is easily recognized by its bold form and edentate (or unidentate) labrum (figs. 1, 58, 59). None of these five groups can be separated from Scopaeus as herein redefined. Euscopaeus and Scopaeomerus are new synonyms of Scopaeus ; Scopaeodera, Scopaeoma, and Scopaeopsis are revised status junior synonyms of Scopaeus ; all possess a stridulum and have long, tapered metakatepisternal processes.

Even with all the species assigned to the Eurasian, African, and New World species groups, the large cluster of unassigned species remaining in Scopaeus represent a paraphyletic group. This paraphyly will continue so until the currently included species are studied and distributed among existing and newly proposed species groups and the species remaining in the nominate group share the same unique, derived features. When done, it might then make sense to develop a subgeneric classification.

DISCUSSION: In 1840, a year after Erichson (1839) described Scopaeus without included species, he added four European, one North African, three North American, and one South American species. Since then, hundreds more have been discovered and the infrageneric groupings have multiplied. Some were described as genera and later reduced to subgenera or synonyms of Scopaeus while others were described as subgenera. To date 20 genus-group names have been used for species of Scopaeus (table 1).

Among the Eastern Hemispheric subgeneric names five were applied to the fauna of Europe, two to Asia, and two to Africa; two names are junior homonyms (see table 1 and synonymic list for Scopaeus ). Prior to the present work all but two of the subgenera of Scopaeus in the Palaearctic region were reduced to synonyms and the species distributed among various species groups by Frisch. Fagel moved all the sub-Saharan species to species groups. Now most of the named, Old World species reside in species groups.

Among the genus-group names for the Western Hemisphere seven were named for North American species and one for a South American species. Three of the names were synonymized with Scopaeus , in the mid-19th and 20th centuries. No named species groups were proposed for the New World species.

As yet no comprehensive infrageneric classification has been proposed for Scopaeus nor will there be one in the present publication. Despite the former subgeneric classification of Scopaeus and the currently developing efforts to organize species groups, Scopaeus s.s. was and may still be a paraphyletic group until either an infrageneric classification has been universally applied to the genus or entirely abandoned.