Erichsonius (Sectophilonthus) muellerae sp. nov.

(Figs. 1–28, 58–59, Tables 1, 2)

Type locality. South Africa: KwaZulu-Natal, iSimangaliso Wetland Park | Sodwana Bay, 27°32.4´S; 32°40.4´E.

Type material. Holotype ♂ (Figs. 1–9): SOUTH AFRICA: || South Africa, KwaZulu-Natal | Isimangaliso Wetland Park | Sodwana Bay; swamp in litoral | forest; 27°32.4´S; 32°40.4´E | 23.i.2019; J.Janák lgt. || Holotypus ♂ | Erichsonius | (Sectophilonthus) | muellerae sp. n. | det. Janák & Uhlig 2019 || (TMSA). Paratypes: same data as holotype, 12 ♂, 10 ♀ (JJRC, TMSA). || R. S. Africa 30.i.1994 | 27°37’S / 32°41’E [corrected co-ordinates: 27°32’S / 32°40’E] leg. Uhlig | Natal: Sodwana Bay NP | wet forest, sievings: reed, | Cyperus, Ficus leaf litter || 2 ♂ # 1 ♀ (MFNB). || R. S. Africa: 14.-15.xi.1996 | 27°37’S / 32°41’E [corrected co-ordinates: 27°32’S / 32°40’E] Natal: | Sodwana Bay NP, riverine | forest litter,Ficus + Cyperus | leaf litter sievings, M.Uhlig || 1 ♀ (MFNB). All paratypes with additional label: || Paratypus ♂ | Erichsonius | (Sectophilonthus) | muellerae sp. n. | det. Janák & Uhlig 2019 || in males and Paratypus ♀ | Erichsonius | (Sectophilonthus) | muellerae sp. n. | det. Janák & Uhlig 2019 || in females.

Description. Length LCo [mm] 4.8 ± 0.3 (4.5 / 4.2–5.2). Anterior body length L Ca [mm] 2.4 ± 0.1 (2.2 / 2.1–2.5).

Colour. Pitchy black to almost black. Posterior margins of tergites, sometimes anterior margin of pronotum and suture dark reddish brown. Genital segment yellowish brown to pitchy brown, styli of tergite IX pitchy brown or pitchy black. Legs dark yellowish brown with tibiae partly infuscate. Antennae pitchy black with antennomere 1 and base of segments 2 and 3 yellowish brown, antennomeres 8 to 11 light yellowish brown. Mouthparts dark yellowish brown, mandibles pitchy brown.

Head (Figs. 1, 3) of rounded square to slightly transverse-rectangular shape, slightly shorter as long as or slightly longer than across eyes, temples parallel-sided or only slightly narrowed posteriad, eyes slightly prominent to prominent, slightly to distinctly shorter than temples. Head transversally convex, shorter than pronotum but about as wide as pronotum. Antennae (Figs. 1, 6) long and slender, all segments longer than wide. Length, width and indices of all antennomeres of holotype are presented in Table 1; variation of length, width and indices of antennomeres 5 and 10 are presented in Table 2.

Pronotum (Figs. 1, 4) longer than wide, of inverted trapezoid shape with rounded angles, slightly narrowed posteriorly, broadest at anterior third, transversally convex.

Scutellum (Figs. 1, 5) moderately finely and sparingly punctate, punctation consisting of 13–20 punctures, punctures slightly denser than on elytra..

Elytra (Figs. 1, 5) markedly longer and wider than pronotum. Elytra together slightly to moderately longer than wide, of rounded rectangular or slightly trapezoid shape, sides slightly dilated posteriorly, broadest at third fourth to fourth fifth of their length. Elytra slightly convex transversally. Posterior wings completely developed.

Abdomen (Fig. 1) staphylininae-shaped (abdominal outline long-ovoid with tergite III narrow, tergites IV and V broadest, tergite VI and following continuously narrower). Terga III to V with feeble basal impressions. Tergum VII with complete membranous palisade fringe at its posterior margin.

Pubescence, punctation and microsculpture. Pubescence dark. Punctation of head (Figs. 1, 3) and pronotum (Figs. 1, 4) moderate and sparse, temples and posteriomedial area of head more densely and finely punctate. Diameter of punctures between eyes slightly larger than one median eye facet. Microsculpture on head distinct, consisting of nearly isodiametric (clypeus) to net-like meshes, those of pronotum less distinct, markedly weaker with more slightly transverse meshes but especially on posterior part of pronotum more long-transverse. Punctures of elytra (Figs. 1, 5) moderately dense and moderately fine. Elytra without microsculpture. Abdomen (Fig. 1) finely and densely punctate, microsculpture more distinct than on pronotum, consisting of dense, slightly transverse to net-like meshes, these dense. Interior puncture series of pronotum consisting of 1+12 ± 1 (13|13 / 9–13) punctures.

Male. Tarsomeres 1 to 4 of protarsus dilated (Fig. 1), as broad as or slightly broader than apex of protibia. Abdominal tergite X (Figs. 20–21) evenly curved apically, posterior margin with (3)2-1-2(3) long and strong bristles and fine cuticular fringes. Posterior margin of sternite VIII (Figs. 13, 14) with broad arcuate emargination and moderately long and moderately strong bristles. Sternite IX (Fig. 22) markedly narrowed apically, with an asymmetrical basal process, posterior margin rounded, with medium-sized and fine apical bristles at posterior margin distributed according to Fig. 22. Aedeagus (Figs. 7–12, 15–19). Aedeagus and parameral rami strongly sclerotized. Parameral side facing ventrally when in repose (resting position of aedeagus 0° according to Coiffait 1972). For measurements and proportions see Table 2. Parameral rami slightly exceeding top of median lobe [i (DA-Pm): L Pm +0.022 (0.021 -0.058)]. Median lobe in overall outline rounded apically, but with medially slightly emarginated apex, with sides slightly emarginate in apical tenth. Median lobe slightly flattened on ventral side of its tube along longitudinal axis. Distal orifice situated dorso-apically.

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TABLE 2. (Continued)

A aedeagus, male copulatory organ. C head. Ca anterior body (head + pro-, meso- and metathorax). Co body. D distance. DA-Pm distance from top of median lobe to top of parameral rami: + if parameres exceeding top of median lobe; - if parameres not reaching top of median lobe. E elytron(elytra). HT holotype. i index or ratio. L length. LA length of aedeagus (length of median lobe). LC length of head. LCa length of anterior body (measured from anterior margin of clypeus to most posterior margin point of elytra, neckpronotum-elytra in normal position, not stretched or pressed together). LCo length of body; measured from anterior margin of clypeus to most posterior margin point of body (in general posterior end of tergite IX or X), neck-pronotum-elytra-abdomen in normal position, not stretched or pressed together. LE length of elytra. LO length of eyes. LP length of pronotum. LPm length of paramere(s). LTe length of temples. L5(L10) length of 5th(10th) antennal segment. Max maximum. Min minimum. n total of specimens. O eye. P pronotum. Pm paramere(s). PT paratype (-s). Pr protuberance. SD standard deviation. T width. TA width of top of median lobe. TAPr width of protuberance of median lobe. TE width of elytra. TO width of head across eyes. TP width of pronotum. TTe width of head at the temples. Te temple(-s). x arithmetic mean.

Parameral rami in the middle parts of ventral side broad and flat between the lateral and the median keel thus in cross-section triangular. Parameral rami, in basal two thirds divergent from median lobe, in apical third spoonlike dilated and markedly twisted along longitudinal axis; spoon-like apical part at inner side with few (about 10) moderately long hairs more basally and with 7–9 peg setae more distally located in spoon (Figs. 10–12, 19). Internal sac with fine and moderate spines, squamous structures and one pair of elongate sclerites and one pair of sclerites forming horseshoe shape as in (Figs. 15–18).

Female. In general appearance similar to male. Anterior tarsomeres less dilated than in males. Abdominal tergite X (Figs. 23–24) rounded wedge-shaped, somewhat slenderer than those of males, apex rounded, bearing (4)3- (1)-3(4) rather long apical setae. Valves (lateral sternal sclerites IX + coxite + stylus) with lateral sternal sclerites IX slightly longer than coxite + stylus (Figs. 25–28). Coxite long and moderately broad, stylus moderately large. Chaetotaxic formula (for explanation see Uhlig 1988 and Uhlig & Watanabe 1992):

Valval chaetotaxy: Digging spines: z1, y2; small spines: y6, y7. Large and strong bristles: y3α, y4, y5α. Large and thin bristles: z2, y3β. Fine setae: all others.

Measurements, indices and variability. See Table 2.

Differential diagnosis. For position of the new species (and the second species described below) in the genus Erichsonius, see paragraph above before description of the species. Erichsonius (S.) muellerae sp. nov. shares similar characters as below described E. (S.) sodwanaensis sp. nov., but it can be distinguished from this species mainly by coarsely and sparsely punctured (best seen on tempora near interior margin of eyes) and slightly more rounded head, smaller body size, parameral rami only slightly exceeding top of median lobe and antennomere 8 yellowish, similar as antennomeres 9–11.

Derivatio nominis. This species is dedicated to Ruth Müller (Pretoria, South Africa, former curator of Ditsong Museum, Pretoria), who helped us significantly during our trips to the Republic of South Africa and supported our study of Staphylinidae.

Distribution and bionomics. Erichsonius (S.) muellerae sp. nov. is known only from three very close localities situated before the entrance into the fenced areas of Sodwana Bay in iSimangaliso Wetland Park, KwaZulu-Natal Province (South Africa).All specimens of the new species were found in wet littoral forest, most of them by treading a swamp together with the below described E. (S.) sodwanaensis sp. nov. (Fig. 58). A few specimens of E. (S.) muellerae sp. nov. were sifted from leaf litter in two additional places also in wet litoral forest, but where no specimens of S. (E.) sodwanaensis sp. nov. were collected (Fig. 59).