Contreuconnus Jałoszyński, 2024, gen. n.
Creators: name: Jałoszyński, Paweł
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Contreuconnus

description: Contreuconnus gen. n.   
 Type species: Euconnus ambatolampyensis Franz, 1986b: 237. (here designated).   
 Diagnosis. Body (Figs 324, 335) with distinct constriction between head and pronotum and between pronotum and elytra; thick bristles present on genae and outer regions of hypomera (Fig. 326); head (Figs 325–326, 332–333, 336–337) round, with eyes situated closer to mandibular bases and antennal fossae than to occipital constriction; antennal fossae separated at middle by distance wider than width of scape (Fig. 325); antenna (Figs 327, 338) gradually thickening distally; frontoclypeal groove lacking; posterior margin of vertex (Figs 335, 336) rounded or nearly straight and not bulging posterodorsally; submental region (Fig. 333; smn) lacking hypostomal sutures; hypostomal ridges (Fig. 333; hr) extending posteromesad and not reaching posterior tentorial pits, but laterally demarcating slightly elevated smooth ‘platform’; pronotum (Fig. 332) bell-shaped, broadest in front of middle, with two pairs of antebasal pits, inner pair connected by shallow transverse impression, pronotum lacking lateral and sublateral carinae; prosternum (Fig. 333) with precoxal (= basisternal) region much shorter than procoxal rests, prosternal process lacking; notosternal sutures (Fig. 333; nss) complete; procoxal cavity closed by postcoxal prosternal lobe overlapped by (but not fused with) postcoxal mesal lobe of hypomeron; hypomeral ridges nearly complete (slightly rounded off and less distinct in anterior fourth), each delimiting narrow subtriangular inner (adcoxal) unsculptured region of hypomeron; mesoventral intercoxal process (Fig. 333 msvp) elongate subtriangular, barely marked, reaching middle of mesocoxal rests and not separating mesocoxae; metaventrite lacking anterior metaventral process; metaventral intermetacoxal process (Fig. 333; mtvp) short and broad, with concave posterior margin, widely separating metacoxae; elytra (Fig. 332) lacking basal foveae; mesoscutellar shield not exposed between elytral bases (Fig. 332); aedeagus (Figs 328–331, 339–342) with symmetrical median lobe and strongly sclerotized, asymmetrical and complex endophallus, and with free, slender parameres.   
 Description. Body form (Figs 324, 335) elongate and slender, strongly convex, with distinct constrictions between head and pronotum and between pronotum and elytra.   
 Head (Figs 325–326, 332–333, 336–337) rounded; compound eyes situated much closer to mandibular bases and antennal fossae than to occipital constriction, each with posterior emargination (Figs 326, 337); tempora rounded; vertex (Figs 325, 336) not bulging posterodorsally, confluent with frons, its posterior margin rounded. Bristles present on genae (Figs 326, 333, 337). Occipital constriction (Fig. 332) about as broad as half width of head; ‘neck’ region strongly broadening posterad. Antennal fossae large and situated anterolaterally, separated at middle by median longitudinal frontal area wider than scape (Fig. 325). Frontoclypeal groove lacking; clypeus short, rounded anteriorly, with lateral margins converging towards labrum. Gular plate (Fig. 333; gp) subtrapezoidal, covered with transverse microsculpture, lacking gular sutures; posterior tentorial pits (Fig. 333; ptp) situated clearly in front of transverse impression demarcating ventrally 'neck' region, each strongly elongate and weakly curved.   
 Submentum (Fig. 333; smn) laterally not demarcated by hypostomal sutures; mentum subtrapezoidal, broadest near base, with anterior margin rounded on sides and indistinctly concave at middle; prelabium short with narrowly separated insertions of labial palps and with narrow and short ligula bearing two long setae; labial palpomere 1 annulate, palpomere 2 strongly elongate, subcylindrical, nearly 4 times as long as broad, palpomere 3 narrow, elongate but distinctly shorter than 2, tapering distally and weakly curved. Maxilla generalized as in most Stenichnini, with large semicircular cardo, subtriangular basistipes, elongate mediostipes, elongate lacinia and galea, each with thick and not very numerous setae along distomesal margin, palpifer elongate, maxillary palp with distinctly elongate and distally slightly broadening palpomere 1, long, pipe-shaped and weakly curved palpomere 2, strongly elongate and slender fusiform palpomere 3 about twice as wide as palpomere 2, and minute, strongly elongate subconical and pointed palpomere 4. Mandibles broadly subtriangular, each with one preapical mesal tooth and short setose prostheca. Labrum strongly transverse, with rounded anterior margin, and with sparse, symmetrically distributed dorsal setae directed anterad.   
Antenna (Figs 327, 338) long in relation to body length, slender, with scape and pedicel each elongate; flagellomeres loosely assembled; antenna gradually and weakly thickening distally. All antennomeres sparsely setose.  
 Prothorax in dorsal view (Fig. 332) bell-shaped, broadest distinctly in front of middle. Anterior and lateral margins confluent, without anterior angles; lateral margins strongly rounded in anterior half and sinuate posteriorly; posterior corners distinct but blunt; posterior margin weakly convex posteriorly. Pronotal base with two pairs of antebasal pits, inner pair connected by shallow transverse impression; sublateral and lateral carinae lacking. Bristles present only on anterior regions of outer hypomera (Figs 332–333), slightly expanding onto dorsum. Hypomeral ridges complete (slightly rounded off anteriorly), demarcating narrow and unsculptured inner regions of hypomera. Prosternum (Fig. 333) slightly shorter than half length of prothorax, with precoxal region much shorter than coxal rests; notosternal sutures (Fig.333; nss) complete.Prosternal process not developed; posterior margin of furcasternum with shallow arcuate median emargination. Procoxal cavities closed; postcoxal hypomeral lobe overlapping (but not fused to) postcoxal prosternal lobe.   
Meso- and metanotum not studied; mesoscutellar shield not exposed between elytral bases.  
 Mesoventrite (Fig. 334) transverse, with massive prepectus, subquadrate and setose anteromedian impressions functioning as procoxal rests (Fig. 334; pcr) only anteriorly separated at middle by short longitudinal carina posteriorly not connected to broadly subtriangular and barely marked mesoventral intercoxal process (Fig. 334; msvp) which posteriorly reaches only middle of mesocoxal rests.   
 Metaventrite (Fig. 334) subrectangular, anteriorly fused with mesoventrite, lacking anterior metaventral process; metaventral intermetacoxal process (Fig. 334; mtvp) short and broad, with concave posterior margin, widely separating metacoxae. Metanepisterna and metepimera fully demarcated and narrow, partly exposed in ventral view.   
Legs short, lacking peculiar features.  
Elytra (Figs 324, 332, 335) together oval, with humeral calli, lacking basal impressions, humeral denticles and basal foveae.  
Hind wings in the only known species fully developed.  
Abdomen subtriangular, slightly shorter than metaventrite, with six exposed sternites (sternites III–VIII), division between VII and VIII slightly less distinct than between the remaining segments.  
Aedeagus (Figs 328–331, 339–342) with symmetrical median lobe and strongly sclerotized, asymmetrical and complex endophallus, and with free, slender parameres.  
 Etymology. Contreuconnus combines contra (Latin “against”) with Euconnus. Gender masculine.   
 Composition and distribution. Contreuconnus includes one nominal species known to occur in Central Madagascar (Alaotra-Mangoro and Vakinankaratra Regions).   
 Remarks. Contreuconnus was included in the key to world genera of Stenichnini (Jałoszyński 2024) under the code name ‘Mdg genus 2’. It is most similar to Euconnus, but does not have the highly elevated and complete mesoventral process that in Euconnus completely separates mesocoxae.
description: Published as part of Jałoszyński, Paweł, 2024, The ' curse of Horaeomorphus' (almost) lifted. Revision of misplaced species from Madagascar, Comoros and Mascarenes (Coleoptera, Staphylinidae, Scydmaeninae), pp. 1-96 in Zootaxa 5505 (1) on pages 87-88, DOI: 10.11646/zootaxa.5505.1.1, http://zenodo.org/record/13745912