Scydmaenichnus Reitter

Jałoszyński, Paweł, 2013, Revision of subgenera of Stenichnus Thomson, with review of Australo-Pacific species (Coleoptera, Staphylinidae, Scydmaeninae), Zootaxa 3630 (1), pp. 39-79 : 51-52

Subgenus Scydmaenichnus Reitter

Scydmaenichnus Reitter, 1905: 99 (as subgenus of Stenichnus ). Type species: Stenichnus fossifrons Reitter, 1905 (designated by Franz in Newton & Franz (1998)).

Lectotype designation. Redescription of this subgenus given below is based on the morphology of a single male type specimen of Stenichnus fossifrons Reitter , the type species of Scydmaenichnus , preserved at HNHM. This specimen ( Figs. 45–51 ), having a status of a syntype (Reitter (1905) mentioned more than one specimen in his original description of S. fossifrons ), is here designated lectotype, in order to ensure the stability of nomenclature and provide a unique name-bearing type for Stenichnus fossifrons .

Revised diagnosis. A subgenus of Stenichnus showing the following differences in relation to Stenichnus s. str.: head in males modified, with buckling frons (non-modified in Stenichnus s. str.); setose impressions of mesoventrite broadly separated from mesocoxal cavities (narrowly separated in Stenichnus s. str.); each elytron with two rudimentary foveae (one deep and one rudimentary in Stenichnus s. str.); and hind wings absent (present in Stenichnus s. str.).

Redescription. Body ( Fig. 45 ) strongly convex, elongate and relatively slender, with long appendages, vestiture moderately long and dense.

Head ( Figs. 46–48 ) typical for Stenichnus , with short tempora, eyes located posteriorly, fronto-clypeal groove present; trapezoidal submentum with long posterior margin laterally demarcated from hypostomae; hypostomal ridges complete. In males frons between eyes and antennal insertions expanded anteriorly and forming large protuberance demarcated from vertex by impression ( Fig. 47 ; fr). Antennae ( Fig. 45 ) slender, gradually thickening towards apices.

Prothorax ( Figs. 45, 48 ) in dorsal view with rounded anterior and lateral margins of pronotum, with transverse row of four small ante-basal foveae, without lateral marginal carinae or edges; hypomera ( Fig. 48 ; hy) not demarcated from notum. Prosternum ( Fig. 48 ) with short basisternal part ( Fig. 48 ; bs), procoxal cavities ( Fig. 48 ; pcc) with anterior marginal carina and separated in middle by fine prosternal intercoxal carina; notosternal sutures ( Fig. 48 ; nss) complete.

Mesoventrite ( Fig. 48 ;) with narrow anterior ridge, lateral asetose impressions ( Fig. 48 ; ai) separated in middle and lateral setose impressions ( Fig. 48 ; si) narrowly separated in middle and broadly separated from mesocoxal cavities ( Fig. 48 ; mscc); mesocoxal projection ( Fig. 48 ; mcp) with carina and with posterior lobe ( Fig. 48 ; pl) bearing dense setae along posterior margin; mesoventral intercoxal process ( Fig. 48 ; msvp) narrow, not fused with metaventrite.

Metaventrite ( Fig. 48 ) broader than long, with metaventral anterior process ( Fig. 48 ; mtap) concealed by dense setae; metaventral intercoxal process ( Fig. 48 ; mtvp) broad and short, with distinct median notch.

Elytra ( Fig. 45 ) oval, with highly reduced humeral calli, narrow at base, each elytron with two rudimentary basal foveae barely noticeable in dry-mounted specimens. Hind wings absent.

Legs ( Fig. 45 ) long; femora clavate, tibiae slender, tarsi strongly elongate.

Abdominal sternites VII and VIII separated by indistinct suture.

Aedeagus ( Figs. 49–50 ) with structures typical for Stenichnus , ie., with ventral projection ( Fig. 49 ; vp), mesoventral projection ( Fig. 49 ; mvp) and lightly sclerotized endophallus ( Fig. 49 ; end) with denticulate surface; parameres free and slender, with apical setae.

Distribution and composition. Five species of Stenichnus (Scydmaenichnus) are distributed in Cyprus, Israel and Turkey. Some old records refer to " Syria " (Davies 2004), a territory at that time different from the present country, so these data may concern adjacent countries of the Middle East.

Remarks. The large number of characters shared with Stenichnus s. str. and only a few minor differences found during the present study ( Table 1 ) justify the placement of Scydmaenichnus as a subgenus. In the available material (single and fragile type specimen) it was not possible to examine the structure of mandibles and prementum. The mandibles seem to be falciform in S. fossifrons , but their proximal parts were not visible in a temporary transparent mount. The broadly separated bases of maxillary palps suggest that the prementum is modified in a similar way as in Stenichnus s. str., but further morphological study is necessary to analyze all important structural details of the mouthparts.

Figures

FIGURES 45 – 51. Stenichnus (Scydmaenichnus) fossifrons Reitter, lectotype male. Dorsal habitus (45), head in frontal (46) and left lateral (47) views, venter (48), aedeagus in ventral (49) and lateral (50) views, and set of original labels (51). Abbreviations: adw, apex of dorsal wall; ai, asetose impression of mesoventrite; bs, basisternal part of prosternum; cl, clypeus; end, endophallus; fr, frons; hy, hypomeron; lb, labrum; lw, lateral wall; mcp, mesocoxal projection; mscc, mesocoxal cavity; msvp, mesoventral intercoxal process; mtfa, metafurcal arm; mtvp, metaventral intercoxal process; mvp, meso-ventral projection; nss, notosternal suture; pcc, procoxal cavity; pcs, procoxal socket; pl. posterior lobe of mesocoxal projection; pre, prepectus; si, setose impression of mesoventrite; v 3, metaventrite; vp, ventral projection; vt, vertex; vw, ventral wall.