Archiconnus Franz

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 : 525-529

Archiconnus Franz

Archiconnus Franz, 1980: 189 . Type species: Archiconnus huallaganus Franz, 1980 (monotypy).

Revised diagnosis. Male and female: head short, with vertex not expanded dorso-caudad; thick and long bristles absent on head but present on sides of prothorax; fronto-clypeal groove absent; maxillary palpomere III strongly thickened and stout; mandible without mesal sub-median tooth; antennae with club composed of antennomeres IX– XI; pronotum with rounded sides and weakly arcuate anterior and posterior margins; base of pronotum with shallow and indistinctly demarcated pair of sub-median ante-basal pits, without lateral and sub-lateral carinae; basisternal part of prosternum much shorter than procoxal cavities; prosternum without intercoxal process or carina; prothoracic hypomeral ridges incomplete; mesoventral intercoxal process long, narrow and strongly expanding ventrally (keel-shaped); mesoventrite with asetose lateral impressions behind anterior ridge, without setose impressions; mesothorax without lateral foveae; mesocoxal projection with posterior lobe; metacoxae narrowly separated by subtrapezoidal metaventral intercoxal process; each elytron with single rudimentary and asetose basal fovea. Male: parameres slender, not fused with median lobe, with apical setae; internal armature of aedeagus asymmetrical.

Redescription. Body of male ( Fig. 1 ) strongly convex, elongate but moderately slender, with moderately long appendages, BL below 1 mm; cuticle glossy, brown, moderately densely setose.

Head ( Figs. 1–2 , 4–5 ) only slightly elongate, rounded, with large eyes; occipital constriction ( Figs. 4–5 ; occ) in the narrowest place much wider than half HW; tempora ( Fig. 4 ; tm) long and convergent caudad, without bristles; vertex ( Fig. 4 ; vt) broader than long, rounded, convex, not projecting dorso-caudad; frons ( Fig. 4 ; fr) transverse and subtriangular; fronto-clypeal groove absent; antennal insertions broadly separated.

Labrum transverse with rounded anterior margin. Mandibles ( Figs. 4–5 ; md) symmetrical, each with broad basal part, without noticeable prostheca, and with slender and curved distal part, without mesal tooth. Each maxilla ( Fig. 5 ) with subtriangular basistipes ( Fig. 5 ; bst), elongate galea ( Fig. 5 ; gal) and lacinia ( Fig. 5 ; lac) and long maxillary palp ( Fig. 5 ; mxp) composed of relatively long palpomere I, strongly elongate, pedunculate palpomere II, broad and stout palpomere III broadest near middle, and small, subconical and pointed palpomere IV.

Labium ( Fig. 5 ) with large and transverse submentum ( Fig. 5 ; smn) sharply demarcated from gular plate ( Fig. 5 ; gp) and laterally fused with postcardinal parts of hypostomae (Fig. 52; h), subtrapezoidal mentum ( Fig. 5 ; mn); and short prementum bearing narrowly separated at bases small 3-segmented labial palps ( Fig. 5 ; lp). Hypostomal ridges ( Fig. 5 ; hr) long and connecting between base of submentum and gular plate.

Gular plate ( Fig. 5 ; gp) large and strongly narrowing anterad; gular sutures ( Fig. 5 ; gs) superficial; posterior tentorial pits ( Fig. 5 ; ptp) distinct, located at base of submentum.

Antennae ( Figs. 1–2 ) with distinct club composed of antennomeres IX–XI.

Pronotum ( Figs. 1–2 ) in dorsal view oval with strongly rounded lateral margins, indistinct anterior and posterior corners; without marginal carinae or edges and without sub-lateral carinae; base of pronotum with shallow and indistinctly demarcated pair of sub-median ante-basal pits; sides of pronotum with dense, thick and long bristles.

Prosternum ( Fig. 6 ) with short basisternal part ( Fig. 6 ; bs) indistinctly demarcated from procoxal cavities ( Fig. 6 ; pcc); median part of sternum without intercoxal carina or process; procoxal sockets ( Fig. 6 ; pcs) closed by lateral lobes of sternum; hypomera ( Fig. 6 ; hy) elongate; hypomeral ridge ( Fig. 6 ; hyr) visible only in posterior half of hypomeron; pronotosternal sutures ( Fig. 6 ; nss) entire.

Mesoscutellum very small, heart-shaped, broader than long, barely visible between bases of elytra; mesoscutoscutellar suture indiscernible in slide preparation.

Mesoventrite ( Fig. 7 ) with narrow anterior ridge ( Fig. 7 ; ar) and median projection of anterior ridge ( Fig. 7 ; par); mesoventral intercoxal process ( Fig. 7 ; msvp) narrow and keel-shaped; mesanepisternum with long prepectus ( Fig. 7 ; pre) and posterior part not visible in ventral view; mesepimeron not visible in ventral view; sides of mesothorax without foveae; mesoventrite with indistinctly delimited subtriangular lateral asetose impressions ( Fig. 7 ; ai); mesocoxal projections ( Fig. 7 ; mcp) strongly projecting, with mesocoxal sockets ( Fig. 7 ; mscs) located on their mesal surface and with distinct asetose posterior lobes ( Fig. 7 ; pl).

Metaventrite ( Fig. 7 ; vIII) strongly transverse, anteriorly fused with mesoventrite, posteriorly moderately deeply bisinuate and with narrow median subtrapezoidal metaventral intercoxal process ( Fig. 7 ; mtvp) bearing median notch. Metanepisterna and metepimera not visible in ventral view, narrow.

Metafurca ( Fig. 7 ) with very short and broad stem and divergent lateral furcal arms ( Fig. 7 ; lmfa).

Elytra ( Figs. 1–2 ) oval, each with single rudimentary and asetose basal fovea located in shallow basal impression; humeral calli well-marked and developed as longitudinal protuberances; elytral apices unmodified, separately rounded.

Legs ( Figs. 1–2 , 7 ) moderately long and slender; procoxae subglobose, mesocoxae slightly elongate, metacoxae transverse, stout; all trochanters short; all femora weakly clavate; tibiae short and slightly expanded near middle; tarsi short and stout.

Abdominal sternites ( Fig. 7 ) unmodified, suture between VII and VIII barely marked.

Aedeagus ( Figs. 8–9 ) strongly elongate, thin-walled, with internal armature composed of moderately darkly sclerotized tubular structure, and with free (i.e., not fused with median lobe) and slender parameres bearing apical setae.

Distribution and composition. Archiconnus is represented by a single species known from the northern part of Peru.

Remarks. Two species of Archiconnus were described by Franz (1980, 1994), but the other one, known from Mexico, is in the present paper placed in a separate genus.

Archiconnus was described as a genus similar to Euconnus (Napochus) , with a diagnostic set of characters including contiguous hind coxae, pronotum with rounded sides, strongly enlarged maxillary palpomere III, round head with bristles similar to those on pronotum, large and anteriorly located eyes, narrow occipital constriction, antennal club composed of three antennomeres, pronotum without lateral carinae near hind angles, with a pair of approximate ante-basal foveae, elytra with a single basal fovea, and aedeagal parameres free (i.e., not fused with the median lobe). However, one of these characters is in fact not present in Archiconnus : there are no stiff and thick bristles on the head, which is covered with setae as thin as those on elytra, in contrast to pronotal bristles.

Archiconnus is highly similar to Euconnus s. str., from which it differs in lacking the fronto-clypeal groove (present in Euconnus s. str.); mandibles without subapical mesal tooth (with tooth in Euconnus s. str.); absent sublateral pronotal carinae (present in Euconnus s. str.); internal parts of prothoracic hypomera demarcated laterally by an incomplete hypomeral ridge (complete in Euconnus s. str.) and strongly expanding mesally over sides of prosternum and therefore concealing a large part of procoxal sockets (largely visible in Euconnus s. str.); lateral impressions of mesoventrite asetose (setose in Euconnus s. str.); absent ventral and dorsal foveae on mesoventrite (present in Euconnus s. str.); presence of distinct posterior lobe of mesocoxal projection (absent in Euconnus s. str.); nearly contiguous metacoxae (moderately broadly separated in Euconnus s. str.); and each elytron with a single rudimentary fovea barely discernible even in transparent mounts (two deep foveae in Euconnus s. str.). The number of these differences justifies the placement of Archiconnus as at least a separate subgenus within Euconnus , but since the character states within the enormously large Euconnus and its many subgenera are still very poorly studied, for the time being this taxon should be treated as a genus.

The indistinctly demarcated basisternal part of prosternum, lack of prosternal intercoxal carina, procoxal sockets largely concealed under the internal part of hypomeron, which is laterally demarcated by an incomplete hypomeral ridge, and a single rudimentary elytral basal fovea make Archiconnus similar to previously revised Euconnomorphus (Jałoszyński 2012) . However, Euconnomorphus clearly differs from Archiconnus in a slender, strongly elongate maxillary palpomere III (strongly broadened and stout in Archiconnus ); subconically expanded vertex (not expanded in Archiconnus ); two pairs of deep foveae on sides of the mesoventrite (absent in Archiconnus ); and in absence of posterior lobes of mesocoxal projections (present in Archiconnus ). Previously revised Venezolanoconnus (Jałoszyński 2012) is highly similar to Archiconnus in the general body form, the shape of vertex (not subconical), the eyes large in males and rudimentary in females, lack of bristles on sides of the head, the maxillary palpomere III strongly broadened and stout, mandibles without subapical mesal tooth, absent frontoclypeal groove, pronotal base without sub-lateral carinae and with a rudimentary pair of ante-basal pits (only in some species, in others entirely absent), sides of pronotum with dense and long bristles, lack of the prosternal intercoxal carina, presence of asetose impressions of mesoventrite and a similar shape and width of the metaventral intercoxal process. Venezolanoconnus differs from Archiconnus in hypostomal ridges not connected posteromesally (connected in Archiconnus ), antennae gradually thickened distally (with distinct club in Archiconnus ), prothoracic hypomera with the internal part demarcated laterally by complete hypomeral ridges (incomplete in Archiconnus ), absent posterior lobes of mesocoxal projections (present in Archiconnus ) and extremely broad, hyaline parameres laterally embracing median lobe (slender parameres in Archiconnus ).

Archiconnus is also similar to Parapseudoconnus , from which it differs in the hypostomal ridges connected in middle behind the submentum (short, not connected ridges in Parapseudoconnus ), absent prosternal intercoxal carina (present in Parapseudoconnus ), incomplete prothoracic hypomeral ridges (complete or nearly complete in Parapseudoconnus ), postero-lateral (postcoxal) parts of prosternum separated from internal parts of prothoracic hypomera (fused in Parapseudoconnus ), absent ventro-lateral foveae of the mesoventrite (present in Parapseudoconnus ), and the aedeagus with parameres (parameres absent in Parapseudoconnus ).

Archiconnus mexicanus Franz is here separated from A. aberrans and placed in its own genus, Mexiconnus . The differences between these taxa are numerous and commented on in Remarks under the latter genus.

Archiconnus huallaganus Franz ( Figs. 1–9 )

Archiconnus huallaganus Franz, 1980: 189 , Fig. 173.

Material studied. Holotype: 3: three labels ( Fig. 3 ): "Umg. Tarapoto / Peru, lg. Franz" with "SA137 [or "/37']" on the reverse side [white, printed; reverse handwritten], " Euconnus [sic!] / ( Archiconnus ) / huallague [sic!] m. / det. H. Franz" [white, handwritten and printed], " Typus " [red, handwritten] (NHMW). Paratype: Ƥ: same data as for holotype (NHMW).

Diagnosis. This is the only known species of re-defined Archiconnus and can be identified on the basis of the generic characters and the aedeagus.

Redescription. Body of male ( Fig. 1 ) strongly convex, elongate and relatively slender, with moderately long appendages, BL 0.81 mm; glossy, uniformly brown with slightly lighter legs and palps; vestiture slightly lighter than cuticle.

Head ( Fig. 1 ) roundly rhomboidal and slightly elongate, broadest at eyes, HL 0.18 mm, HW 0.15 mm; occipital constriction broader than half HW; tempora slightly shorter than eyes, rounded and gradually convergent caudad; vertex nearly as long as broad, convex, only slightly (not conically) projected dorso-caudad; frons modified, with pair of large lateral median tubercles located antero-mesally to distinct supraantennal tubercles; eyes large and strongly convex, moderately coarsely faceted, nearly circular with shallow posterior emargination. Punctures on head dorsum fine and sparse, inconspicuous; setae long, moderately dense, erect, those on vertex mostly directed caudad, thick bristles absent. Antennae ( Fig. 1 ) slender, with indistinctly demarcated club composed of antennomeres IX–XI, AnL 0.30 mm; antennomeres I–II elongate, III–VII each about as broad as long or only slightly transverse; VIII strongly transverse; IX and X each strongly transverse; XI 1.7x as long as broad, slightly asymmetrical, with subconical, blunt apex.

Pronotum ( Fig. 1 ) in dorsal view elongate oval, with broadly rounded and indistinct front and hind angles, broadest near posterior fourth, PL 0.24 mm, PW 0.21 mm; anterior, posterior and lateral margins rounded; base of pronotum with shallow and indistinctly demarcated pair of sub-median ante-basal pits. Punctures on pronotal disc fine and inconspicuous; setae long, moderately dense and strongly erect, sides of pronotum with dense thick and long bristles.

Elytra ( Fig. 1 ) oval and more convex than pronotum, broadest distinctly behind middle, EL 0.40 mm, EW 0.30 mm, EI 1.33; humeral calli distinct, developed as short longitudinal protuberances; basal impressions indistinct, basal pits barely discernible; elytral apices separately rounded. Punctures on elytral disc as fine as those on pronotum; setae much shorter than pronotal bristles, moderately sparse and suberect. Hind wings well-developed, about twice as long as elytra.

Legs ( Fig. 1 ) moderately long and slender, without modifications.

Aedeagus ( Figs. 8–9 ) elongate, AeL 0.13 mm, median lobe subtriangular, strongly narrowing from base to apex; distal part with truncate apex, in lateral view strongly curved dorsally; internal armature composed of tubular structures located in basal part of median lobe; parameres slender, each with two long and thick apical setae. Female ( Figs. 2 , 4–7 ). Similar to male but clearly differing in non-modified frons and rudimentary eyes ( Fig. 4 ), each composed of a single ommatidium. BL 0.79 mm; HL 0.16 mm, HW 0.14 mm, AnL 0.28 mm; PL 0.23 mm, PW 0.20 mm; EL 0.40 mm, EW 0.30 mm, EI 1.33.

Distribution. Northern Peru, San Martin Province.

Remarks. Franz (1980) included in the type series of A. huallaganus a holotype male and two paratype females (one labeled as allotype). The allotype female, however, clearly differs from the other paratype and the holotype in the body shape and proportions of body parts and it certainly belongs to a different species. Details of the ventral side of this specimen were not studied and it may belong to Archiconnus or Euconnus . In the original description Franz (1980) gives further collecting data for the holotype as a road to Yurimagua, 80 km from Tarapoto, bog or swamp forest ("Sumpfwald"), and collecting data for the paratype female as 40 km from Tarapoto, montane forest, 0 1.10.1968 (it is unclear whether the collecting date refers only to the paratype or both holotype and paratype).

Figures

FIGURES 1 – 3. Archiconnus huallaganus Franz. Dorsal habitus of male holotype (1) and female paratype (2), original set of labels of the holotype (3).

FIGURES 4 – 9. Morphology of Archiconnus huallaganus Franz, paratype female (4 – 7) and holotype male (8 – 9). Head in dorsal (4) and ventral (5) views; prothorax in ventral view (6); pterothorax and abdomen in ventral view (7); aedeagus in ventral (8) and lateral (9) views. Abbreviations: ai, asetose impression; ar, anterior ridge; bs, basisternal part of prosternum; cd, cardo; cp, clypeus; fr, frons; 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; 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; pcc, procoxal cavity; pcs, procoxal socket; pl, posterior lobe; ppf, palpifer; pre, prepectus; ptp, posterior tentorial pit; smn, submentum; tm, temple; vIII, metaventrite; vt, vertex.