Protandroconnus akeratophorus, Jałoszyński, 2020

Jałoszyński, Paweł, 2020, First records of Trichocircus Jałoszyński and Protandroconnus Franz in Mexico, with descriptions of two new species (Coleoptera: Staphylinidae: Scydmaeninae), Zootaxa 4750 (2), pp. 204-210 : 207-209

Protandroconnus akeratophorus sp. n.

( Figs 11–23 )

Type material. Holotype: Mexico (Veracruz State): ♂, four labels: “Cordoba / Mex. Ver. / Dr.A.Fenyes ” [creamy white, printed], “A. FENYES / Collection” [yellow, printed], small green star, “ PROTANDROCONNUS / akera- tophorus m. / P. Jałoszyński, 2019 / HOLOTYPUS ” [red, printed] ( MHNG) . Paratype: ♂, same data as for holo- type, with standard yellow printed “ PARATYPUS ” label ( MHNG) .

Diagnosis. Head in male lacking frontal ‘horn’, with transverse impression in the form of two lateral triangles connected at middle by narrow sulcus; apical, trapezoidal portion of aedagus in ventral view broader than long; parameres absent.

Description. Body of male ( Fig. 11 ) elongate, moderately slender, strongly convex, light brown and covered with yellowish setae and bristles; BL 1.05–1.08 mm.

Head ( Figs 12–16 ) in dorsal view subpentagonal and slightly transverse, broadest at eyes, HL 0.20 mm, HW 0.25 mm; vertex demarcated from frons by arcuate, anteriorly convex ridge that overhangs frons between eyes; frons between eyes with arcuate, posteriorly convex ridge, so that vertex and frons are separated by transverse impression composed of median sulcus between frontal and vertexal ridges and broad subtriangular lateral portions; supraantennal tubercles weakly elevated. Punctures on frons and vertex absent, setal insertions not impressed, setae sparse, short and suberect, sides of frons and lateral portions of transverse impression asetose. Antennae ( Fig. 11 ) slender; AnL 0.48–0.50 mm; scape and pedicel elongate, antennomeres III–VI each about as long as broad or slightly transverse, VII enlarged, distinctly longer and broader than VI, about as long as broad, VIII slightly shorter and narrower than VII, weakly transverse, IX distinctly broader and longer than VIII, distinctly transverse, X distinctly broader but indistinctly longer than IX, distinctly transverse, XI as broad as X, slightly shorter than IX and X combined, about 1.6 × as long as broad.

Pronotum ( Fig. 12 ) broadest near middle; PL 0.30 mm, PW 0.30 mm; sides strongly rounded, anterior and posterior margins indistinctly arcuate. Punctures on pronotal disc fine and inconspicuous, setae sparse, short and suberect, lateral bristles long and erect, in anterior 2/3 standing in various directions, in posterior third directed posterad.

Elytra together oval, broadest slightly behind middle, EL 0.55–0.58 mm, EW 0.43 mm, EI 1.29–1.35; humeral calli weakly elevated, apices separately rounded. Punctures as on pronotal disc; setae slightly longer than those on pronotum.

Hind wings fully developed.

Legs short and robust, unmodified.

Aedeagus ( Figs 20–23 ) moderately slender, AeL 0.13 mm; median lobe in ventral view broadest in basal half, apex subtrapezoidal, in lateral view apical portion strongly bent dorsad; endophallus with weakly sclerotized structures; parameres absent.

Female. Unknown.

Distribution. Southern Mexico.

Etymology. The adjective akeratophorus (= not horned) refers to lack of the frontal ‘horn’ in this species; after Greek a (not) + keras (horn) + pherein (carry), in a Latinized form.

Remarks. Protandroconnus akeratophorus differs from P. peruensis not only in male cephalic modifications, but also in ventral prothoracic and male genital structures. The notosternal sutures in P. peruensis are largely obliterated, but their short anterior and posterior portions are discernible, whereas in P. akeratophorus the sutures ( Fig. 17 ) are entirely absent. In P. peruensis the postcoxal lobe of hypomeron that protrudes mesad seems to be fused with the postcoxal portion of prosternum, whereas in P. akeratophorus the hypomeral lobe ( Fig. 17 ) overlaps with the prosternum, but is not fused to it behind the procoxal cavity. The parameres in P. peruensis are vestigial, conspicuously short, and in P. akeratophorus the aedeagus ( Figs 20–23 ) is devoid of any traces of parameres. All other structures are shared by both species, and those different in the Mexican Protandroconnus (except for the free hypomeral lobe) seem to be reductions. The differences are too minor to justify placing the new species in a separate genus or even subgenus, and the more reasonable approach seems to be modification of the generic diagnosis of Protandroconnus , to include the aforementioned variability in notosternal sutures, postcoxal hypomeral lobes and parameres.

Figures

FIGURES 11–16. Protandroconnus akeratophorus sp. n., male. Dorsal habitus (11), head, prothorax and elytral base in dorsal view (12), head, prothorax and anterior portion of pterothorax in ventral view (13), head in dorsal (14), anterodorsal (15) and lateral (16) views. Abbreviations: bst, basisternal portion of prosternum; gp, gular plate; hr, hypostomal ridge; hyr, hypomeral ridge; ptp, posterior tentorial pit; smn, submentum.

FIGURES 17–23. Protandroconnus akeratophorus sp. n., male. Prothorax in ventral view (17), pterothorax in ventral view (18), pterothorax and abdomen in ventral view (19), aedeagus in ventral (20, 22) and lateral (21, 23) views. Abbreviations: bst, basisternal portion of prosternum; dlf, dorsolateral fovea; hyr, hypomeral ridge; lfa, lateral furcal arm; msvp, mesoventral intercoxal process; mtvp, metaventral intercoxal process; pcr, procoxal rest.