Euconnus (Tetramelus) imaitsanus Franz, 2024

Jałoszyński, Paweł, 2024, The ‘ curse of Horaeomorphus’ (almost) lifted. Revision of misplaced species from Madagascar, Comoros and Mascarenes (Coleoptera, Staphylinidae, Scydmaeninae), Zootaxa 5505 (1), pp. 1-96 : 56-57

Euconnus (Tetramelus) imaitsanus Franz , stat rev.

( Figs 198–208 )

Euconnus (Anthicimorphus) imaitsanus Franz, 1986b: 239 .

Horaeomorphus imaitsanus (Franz) ; Jałoszyński (2014b): 12 (result of placing Anthicimorphus as junior synonym of Horaeomorphus ).

Type material studied. Holotype (Madagascar): ♂, four labels: “Madagascar-Centre / Forét Imaitso / Anjavidilava 2030m / Andingitra-Ambalavao / 17.1. 58 P. Grivaud” [white, printed], “INSTITUT / SCIENTIFIQUE / MADAGASCAR ” [bluish, printed], “ Euconnus / Anthicimorphus / imaitsanus m. / det. H.Franz ” [yellowish, handwritten and printed], “Typus” [red, handwritten] ( NHMW) . Paratype: ♀, same data as for holotype, but with yellow “ PARATYPUS ” label ( NHMW) .

Revised diagnosis. Body ( Fig. 198 ) slender and with impunctate dorsum, asetose, only sides of vertex and pronotal disc with sparse bristles; head ( Figs 199–200 , 206–207 ) round, with vertex posteriorly broadly rounded; pronotum ( Fig. 206 ) bell-shaped, broadest near anterior third, lacking antebasal pits, with distinct transverse antebasal groove; antenna ( Fig. 201 ) slender but short, with all antennomeres elongate (antennomeres 5–7 each about 2.5 times as long as broad); aedeagus ( Figs 202–205 ) in ventral view pear-shaped and broadest near middle, ventral apical wall narrowly subtriangular, dorsal apical wall narrowly subtriangular with rounded apical margin, each paramere broadened in apical region, with four long apical setae.

Redescription. Body of male ( Fig. 198 ) strongly elongate and strongly convex, light brown, legs (especially tarsi), antennae and palps slightly lighter; setae light brown; BL 1.65 mm.

Head ( Figs 199–200 , 206–207 ) in anterodorsal view round, about as long as broad, broadest at eyes, HL 0.28 mm, HW 0.33 mm; length of temple in lateral view ( Fig. 200 ) subequal to eye; vertex and frons confluent, together weakly convex and weakly transverse; vertex posteriorly strongly and evenly rounded; each eye large and weakly convex, shallowly emarginate posteriorly, weakly projecting from head silhouette. Frons and vertex impunctate and asetose, sparse bristles present only on sides of vertex and on genae ( Fig. 207 ). Antenna ( Fig. 201 ) slender but short, as long as half BL, gradually thickened distally, AnL 1.28–1.35 mm, all antennomeres elongate, 5–7 longest and each about 2.5 times as long as broad, four terminal antennomeres weakly differing from proximal ones in stouter form, 11 much longer than 10 and similar in width, about twice as long as broad.

Pronotum ( Fig. 206 ) bell-shaped, broadest near anterior third; PL 0.45 mm, PW 0.33 mm. Anterior margin strongly rounded, lateral margins rounded in anterior half, weakly sinuate in posterior half; posterior corners blunt; posterior margin weakly rounded. Base with transverse groove on entire width. Disc impunctate and with only a few thin and short setae in central area, sparse bristles present on its anterior half and expanding onto anteroventral surface of hypomera ( Fig. 207 ).

Elytra together oval, broadest near middle; EL 0.93 mm, EW 0.63 mm, EI 1.48; humeral calli angulate and weakly elevated, basal elytral foveae indiscernible ( Fig. 206 ). Elytra impunctate and asetose.

Meso- and metaventrite ( Fig. 208 ) with relatively dense, short and recumbent setae.

Legs long and slender, unmodified.

Aedeagus ( Figs 202–205 ) stout, AeL 0.28 mm; in ventral view nearly pear-shaped, broadest near middle, distally gradually narrowing and in subapical region rapidly narrowed; ventral apical wall narrowly subtriangular, dorsal apical wall narrowly subtriangular with rounded distal margin, endophallic sclerites complex and asymmetrical, each paramere slender and slightly broadened in short apical region, with four long apical setae

Female. Externally indistinguishable from male. BL 1.70 mm; HL 0.30 mm, HW 0.33 mm, AnL 0.80 mm; PL 0.45 mm, PW 0.35 mm; EL 0.95 mm, EW 0.68 mm, EI 1.41.

Distribution. Southern Madagascar (Matsiatra Ambony Region).

Remarks. Euconnus imaitsanus can be easily identified by short but slender antennae with antennomeres 5–7 each about 2.5 times as long as broad, sparse bristles on sides of vertex and pronotum, transverse antebasal pronotal groove, asetose elytra, slightly transverse frons + vertex, and unique aedeagal structures.

In addition to the holotype male and one paratype female collected in Imaitso, two females labeled as paratypes are deposited in Franz Coll. ( NHMW). They come from Andranomataza ( Andringitra National Park , Haute Matsiatra Region ). However , these females are not conspecific with the holotype and must be excluded from the type series. Franz’s (1986b) information concerning the type specimens is confusing; he states that the type series consists of seven specimens, but in the same sentence he mentions only six (holotype and one paratype in his collection, which is not true, and four paratypes in Muséum National d'Histoire Naturelle , Paris ), and then continues to characterize the specimens as five collected in Imaitso, and two in Andranomataza .

Figures

FIGURES 198–205. Euconnus (Tetramelus) imaitsanus Franz, holotype. Habitus in dorsal view (198); head in anterodorsal view (199); head and prothorax in lateral view (only bristles on head are shown) (200); antenna (201); aedeagus in ventral (202, 204) and lateral (203, 205) views.

FIGURES 206–208. Euconnus (Tetramelus) imaitsanus Franz, holotype. Head, prothorax and elytral base in dorsal view (206); head, prothorax and anterior region of mesothorax in ventral view (207); pterothorax in ventral view (208). Abbreviations: abg, antebasal groove; gp, gular plate; hr, hypomeral ridge; hyr, hypomeral ridge; msvp, mesoventral intermesocoxal process; mtvp, metaventral process; nss, notosternal suture; pcr, procoxal rest; ptp, posterior tentorial pit; slc, sublateral carina; smn, submentum.