Coecoscopaeus Coiffait

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 : 167-169

Coecoscopaeus Coiffait

Coecoscopaeus Coiffait, 1982: 11 [characters in key and type species in footnote]. Type species: Scopaeus coecus Peyerimhoff, 1906: 56 . Fixed by original designation and monotypy.

— Coiffait, 1984: 209 (description; distribution). — Frisch, Burckhardt, and Wolters, 2002a: 45 (removed from Scopaeina ; notes). — Smetana, 2004: 622 (Palaearctic catalog; incertae sedis). — Janák, 2013: 81 (cited as Caecoscopaeus; differs from Typhloleleupius ).

DIAGNOSIS: The North African Coecoscopaeus has one apical metatibial comb and the mesobasisternum has a shallow, barely discernible, median depression. The Australian Tripectenopus and southern African Typhloleleupius have two apical, metatibial combs and the mesobasisternum of both has a deep, median depression with a strong midlongitudinal furrow.

Like Coecoscopaeus , Sphaeronum also has an apical metatibial comb on the inner apex, the ventral submarginal groove extends from the mandibular base to the neck, and the mesobasisternum has a shallow to feeble median depression. The postprocoxal lobe is moderately long and nearly vertical for Coecoscopaeus but is very short and strongly bent medially for Sphaeronum . The profurcasternum of Coecoscopaeus tapers posteriorly (as in fig. 393) and is well separated from the hypomeron; the profurcasternum of Sphaeronum is wide and contiguous with the hypomeron (fig. 355).

The male’s metafemur and metatibia of Coecoscopaeus each have a row of three and four, respectively, short, thick, spiniform setae, each well separated from the next. The metatrochanter of the males has spines. Males of the other three genera lack these setae or spines. No female specimen was available.

DESCRIPTION: Body length: 3.7 mm.

Head with lateral margin gradually rounded to basal angle; basal angle well developed and strongly rounded; basal margin shallowly emarginate; anterolateral surface without temporal ridge extending posteriorly from lateral surface of supraantennal hump onto temple; lateroventral surface with submarginal groove extending from near base of mandible to neck.

Dorsal cephalic surface polished; microsculpturing absent; punctation moderately dense and moderately coarse; punctation absent from midlongitudinal strip and anterior portion of clypeus.

Clypeal margin without small, conical horn or tumescence mesiad of supraantennal hump.

Eyes absent; ommatidial eyespot absent.

Neck across nuchal groove about one sixth as wide as width of head.

Maxillary palpomere four small, conical.

Labrum with deep emargination; emargination with rounded base (broadly rounded, not V-shaped as illustrated in Coiffait, 1984: 209, fig. 58a); anterior margin with small, rounded denticle on each lobe of labrum.

Prothorax about onethird longer than wide.

Pronotal punctation moderately dense but absent from midlongitudinal strip; surface polished; microsculpturing absent; surface flattened to lateral margin then strongly convex; surface slightly depressed just behind middle to just before posterior margin; midlongitudinal line with slight ridge on posterior quarter.

Notosternal suture presence or absence ambiguous; surface microsculpturing strong.

Prohypomeron with postprocoxal lobe moderately long, nearly vertical, rounded apically, and without setae.

Profurcasternum long, narrow, tapered posteriorly, widely separated from hypomeron.

Procoxal cavity open posteriorly.

Elytra shorter than pronotum; posterior margin with sparse row of setae.

Mesoventrite without midlongitudinal carina; surface with weak, shallow median depression.

Metatrochanter (of male) with two small spines on posterior margin.

Metafemur (of male) with three, thick, spinelike setae on posterior margin.

Metatibia with four, small, spinelike setae on anterior margin (of male only?); apex with comb on inner side.

Tergum VII without palisade fringe on posterior margin.

Tergum IX with middorsal base of male fused.

Segments IX and X of female not examined.

Aedeagus not examined.

Spermatheca not examined.

DISTRIBUTION AND HABITAT: Coecoscopaeus is known only from Tunisia where the four only known specimens of C. coecus were collected from crevices in clay and said to be adapted to subterranean life ( Peyerimhoff, 1906: 56).

NOMENCLATURE: Coiffait (1982: 9) first cited the name Coecoscopaeus , without characters and in the Scopaeina (written as Scopaei), in a key to paederine subtribes and again ( Coiffait, 1984: 5) in the Sommaire. Several pages further on, in a key to Palaearctic paederine genera Coiffait (1982: 11) provided differentiating characters and designated Scopaeus coecus Peyerimoff as the type species for the genus, which then made the name available ( ICZN, 1999: Articles 13.1.1, 13.3). Later he formally, and in more detail, redescribed the genus and species ( Coiffait, 1984: 209–210).

DISCUSSION: Coiffait (1982: 11; 1984: [5], 209) established the monotypic Coecoscopaeus for the anophthalmic, flightless, Tunisian species, Scopaeus coecus Peyerimhoff (1906: 56) . He placed it in the Scopaeina (cited as Scopaei) with Scopaeus because of the narrow neck of both. However, a slender neck is widespread in the subfamily and does not alone define Scopaeus or any other paederine genus. Frisch et al. (2002a: 45) correctly excluded Coecoscopaeus coecus from the Scopaeina but neglected to cite characters that led to that conclusion. Thus, Coecoscopaeus lacks the paraocular, cephalic trichobothrium (see figs. 309, 333) and the tripartite ligular lobe (see figs. 160, 187)—both characteristic of the Scopaeina, and lacks the apomorphic stridulum (see figs. 105, 106) of Scopaeus .

Coecoscopaeus has features entirely absent in the Scopaeina but that are found in three other genera all of which are now assigned to Sphaeronina . These genera, Typhloleleupius , Tripectenopus , and Sphaeronum , are found in Africa, Australia, and South America respectively.

Beyond the syntypic series of three males and one female, apparently, no other specimens of C. coecus have been collected. I was able to study a male syntype. However, since the species is rarely collected and there are few specimens in collections, I was uncomfortable with dissecting or even manipulating the mouthparts to see the hypopharyngeal peg, one of two characters that permit definitive subtribal assignment. The ventral side of the presumed hypopharyngeal peg could be seen between the labial palpomeres.

In addition to the likely presence of a hypopharyngeal peg, the species is assigned to the Sphaeronina because it shares the following features with the other three included genera: (1) the mandibular denticles of each mandible are out of alignment with one another; (2) the mandibles have a groove on the anterolateral surface and the left mandible has a denticle on the ventral surface; (3) the labrum has a deep emargination with a rounded base; (4) the submarginal, lateroventral, cephalic surface has a long groove extending from near the base of the mandibles to the neck; (5) the gular sutures are confluent; (6) the neck is narrow, about one sixth as wide as the greatest width of the head; (7) below the antennal insertion is a prominent subantennal hollow on the gena; (8) the probasisternum is long; (9) the pronotal marginal ridge is absent; (10) the protibia has a large lobe with a deep concavity lined with three diagonally transverse combs; (11) the profemur has a large ridge with a comb on the apex; (12) the slen- der, acute tip of the lateroapical process of tergum IX is strongly bent dorsally.

All but one of the preceding 12 characters are homoplasic. Among those 12, the large denticle arising from the ventral surface of the left mandible is the only unique character that places Coecoscopaeus in the Sphaeronina .

The spines on the metatrochanter and spinelike setae on the metafemur and metatibia of the males are notable. However, since no females were available for study it is uncertain whether they also have these spines and spinelike setae, so the character is not offered as a diagnostic feature of the genus or even species.

The elytra may be fused along the elytral suture, the scutellum appears to be fused to the elytral base, and the wings may be entirely absent.

The illustration of the protibia by Coiffait (1984: 209, fig. 58d) is entirely misleading. As shown there the protibia seems to have a deep notch when in fact the protibia of Coecoscopaeus has a large triangular lobe as illustrated herein for Sphaeronum and Tripectenopus (figs. 350, 351).