Mexiconnus mexicanus (Franz) Franz, 2013

Jałoszyński, Paweł, 2013, Taxonomy of ' Euconnus complex'. Part II. Revision of Archiconnus Franz, Parapseudoconnus Franz and Mexiconnus gen. nov. (Coleoptera, Staphylinidae, Scydmaeninae), Zootaxa 3666 (4), pp. 523-543 : 532-533

Mexiconnus mexicanus (Franz) comb. nov.

( Figs. 10–18 )

Archiconnus mexicanus Franz, 1994: 376 , fig. 72.

Material studied. Holotype: 3: three labels ( Fig. 11 ): "Umg. San-Cristobal / Chiapas, Mexico " with "Mx 16" on the reverse side [white, printed; reverse handwritten], " Archiconnus / mexicanus m. / det. H. Franz" [white, handwritten and printed], " Holotypus " [red, handwritten] (NHMW). A white printed label was added during the present study: " MEXICONNUS / mexicanus / (Franz, 1994) / det. P. JAŁOSZYŃSKI, '13".

Diagnosis. This is the only known species of Mexiconnus and can be identified on the basis of the generic characters and the aedeagus.

Description. Body of male ( Fig. 10 ) slightly flattened, elongate and slender, with long appendages, BL 0.93 mm; glossy, uniformly moderately dark brown with slightly lighter appendages; vestiture slightly lighter than cuticle.

Head ( Figs. 10 , 12 ) short and rhomboidal in shape, broadest at eyes, HL 0.18 mm, HW 0.20 mm; occipital constriction slightly broader than half HW; tempora slightly longer than eyes, strongly convergent caudad and only weakly rounded; vertex strongly transverse, convex, not expanded dorso-caudad; frons confluent with vertex, slightly convex, subtrapezoidal and steeply but not abruptly lowering towards strongly transverse clypeus; supraantennal tubercles feebly marked; eyes large and strongly convex, kidney-shaped and transverse in relation to the long axis of the head, finely faceted. Punctures on head dorsum fine and sparse, inconspicuous; setae long, moderately dense, suberect to erect, those on vertex and tempora directed caudad, thick bristles absent. Antennae ( Fig. 10 ) long and slender, with moderately distinctly delimited club composed of antennomeres IX–XI, AnL 0.50 mm; antennomeres I–IX elongate; X distinctly transverse; XI only 1.2x as long as broad, symmetrical, with broadly rounded apex.

Pronotum ( Fig. 10 ) in dorsal view elongate oval, broadest in anterior fourth, PL 0.25 mm, PW 0.23 mm; anterior margin slightly arcuate; front angles indistinct; lateral margins strongly rounded and strongly convergent towards well-marked, obtuse and blunt hind angles; posterior margin slightly arcuate; base of pronotum with deep and distinct transverse ante-basal groove slightly deepened at each end and not reaching lateral pronotal margins. Punctures on pronotal disc fine and inconspicuous; setae moderately long and dense, suberect, sides of pronotum with thick and long bristles.

Elytra ( Fig. 10 ) oval and only slightly more convex than pronotum, broadest near middle, EL 0.50 mm, EW 0.35 mm, EI 1.43; humeral calli distinct, each developed as short longitudinal protuberance; basal elytral impressions distinct; basal pits indiscernible in a dry-mounted specimen; elytral apices separately rounded. Punctures on median circumsutural part of elytral disc more distinct and denser than those on pronotum but only superficial and with diffused margins, punctures on remaining surface of elytra fine and inconspicuous; setae short, moderately sparse and suberect. Hind wings well-developed, about twice as long as elytra.

Legs ( Figs. 10 , 15–16 ) long and slender; protarsi strongly broadened at base and with dense cushion of long setae on ventral surface, especially on tarsomere I.

Aedeagus ( Figs. 17–18 ) elongate, AeL 0.14 mm, median lobe oval, strongly narrowing from base to subapical region where the distal third of aedeagus is rapidly narrowing and forming slender apical projection; internal armature composed of tubular structures forming an open loop; parameres with broad basal and slender distal parts, each with pointed apex and without setae.

Female. Unknown.

Distribution. Southern Mexico, Chiapas State.

Remarks. In the original description Franz (1994) gives further collecting data: Los Alcanfores (misspelled as "Alcanfones"; a place located west of San Cristóbal de Las Casas), old oak forest, 17.06.1992.

Figures

FIGURES 10 – 11. Mexiconnus mexicanus (Franz). Dorsal habitus of male holotype (10), and its original set of labels (11).

FIGURES 12 – 18. Morphology of Mexiconnus mexicanus (Franz), holotype male. Head in ventral view (12); prothorax in ventral view (13); pterothorax and abdomen in ventral view (14); protarsus in lateral (15) and dorsal (16) views; aedeagus in ventral (17) and lateral (18) views. Abbreviations: ai, asetose impression; ar, anterior ridge; bs, basisternal part of prosternum; cd, cardo; gal, galea; gen, gena; gp, gular plate; gs, gular suture; fo, foramen occipitale; h, hypostoma; hr, hypostomal ridge; hy, hypomeron; hyr, hypomeral ridge; lac, lacinia; lmfa, lateral arm of metafurca; lp, labial palp; mcp, mesocoxal projection; md, mandible; mn, mentum; mscc, mesocoxal cavity; mscs, mesocoxal socket; msff, mesofurcal fovea; mst, mesostipes; msvp, mesoventral intercoxal process; mtvp, metaventral intercoxal process; mxp, maxillary palp; nr, neck region; nss, pronotosternal suture; occ, occipital constriction; par, projection of anterior ridge; pc, prosternal intercoxal carina; pcc, procoxal cavity; pcs, procoxal socket; pf, profurca; pff, profurcal fovea; ppf, palpifer; pre, prepectus; ptp, posterior tentorial pit; smn, submentum; vIII, metaventrite; vlf, ventro-lateral fovea.