Euconnus (Tetramelus) lacertosus 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 : 69-70

Euconnus (Tetramelus) lacertosus Franz , stat rev.

( Figs 256–263 )

Euconnus (Anthicimorphus) lacertosus Franz, 1986b: 245 .

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

Type material studied. Holotype ( Madagascar): ♂, four labels: “Ampigonba {see Distribution} / 5.56, (E. R.)” [white, printed], “ Euconnus / Anthicimorphus / lacertosus m. / det. H.Franz ” [yellowish, handwritten and printed], “Typus” [red, handwritten] ( NHMW).

Revised diagnosis. Body ( Fig. 256 ) moderately slender, only sides of vertex and hypomera with sparse bristles, dorsum asetose; head ( Figs 257–258 ) sub-pentagonal, with vertex posteriorly weakly rounded; pronotum bell-shaped, broadest near anterior third, with barely discernible one pair of punctiform antebasal pits; antenna ( Fig. 259 ) slender but short, with antennomeres 3–7 each weakly elongate and 8–10 each about as long as broad; aedeagus ( Figs 260–263 ) in ventral view almost subrectangular with rounded base and broadest near proximal third, ventral apical wall broadly subtriangular with rounded distal margin, dorsal apical wall with broadly and shallowly emarginate distal margin, each paramere slender, not broadened, with two long apical and two long subapical setae.

Redescription. Body of male ( Fig. 256 ) moderately elongate and flattened, light brown with slightly lighter elytra, legs (especially tarsi), antennae and palps slightly lighter than head and pronotum; setae yellowish; BL 1.18 mm.

Head ( Figs 257–258 ) in anterodorsal view sub-pentagonal, slightly transverse, broadest at eyes, HL 0.20 mm, HW 0.25 mm; temple in lateral view ( Fig. 258 ) about as long as eye; vertex and frons confluent, together weakly convex and weakly transverse; vertex posteriorly weakly rounded; each eye large and strongly convex but weakly projecting from head silhouette, shallowly emarginate posteriorly. Frons and vertex impunctate and asetose, lateral regions of vertex and genae with sparse thick bristles. Antenna ( Fig. 259 ) slender and short, slightly shorter than half BL, with indistinctly delimited tetramerous club, AnL 0.50 mm, antennomeres 1–2 each strongly elongate, 3–7 each weakly elongate and 8–10 each about as long as broad, 11 slightly shorter than 9 and 10 combined, slightly narrower than 10, about 1.8 times as long as broad.

Pronotum bell-shaped, broadest near anterior third; PL 0.30 mm, PW 0.29 mm. Anterior margin strongly rounded, lateral margins strongly rounded in anterior half, weakly sinuate in posterior half; posterior corners blunt; posterior margin nearly straight. Base with one pair of barely discernible, small punctiform pits. Disc impunctate and asetose, bristles present on hypomera.

Elytra together oval, broadest near middle; EL 0.68 mm, EW 0.50 mm, EI 1.35; humeral calli angulate and weakly elevated, basal elytral foveae indiscernible. Elytra impunctate and asetose.

Legs moderately long, slender, unmodified.

Aedeagus ( Figs 260–263 ) relatively slender, AeL 0.20 mm; in ventral view almost subrectangular with rounded base, broadest near proximal third, distally weakly narrowing; ventral apical wall broadly subtriangular and short, with rounded distal margin, dorsal apical wall with truncate and emarginate distal margin, endophallic sclerites complex and asymmetrical; each paramere slender, with two long apical and two long subapical setae.

Female. Unknown.

Distribution. Franz (1986b) deciphered the label locality name as “Ampigomba” and listed this species as one occurring in Madagascar. However, I was not able to find this name (or anything similar) in Internet resources.

Remarks. Euconnus lacertosus is the smallest Malagasy Tetramelus , with BL merely 1.18 mm. It is easy to identify by short antennae with proximal flagellomeres only weakly elongate, pronotum about as long as broad and with one pair of very small, punctiform and barely discernible antebasal pits, asetose dorsum except for sparse bristles on sides of vertex and hypomera, and unique structure of the aedeagus.

Figures

FIGURES 256–263. Euconnus (Tetramelus) lacertosus Franz, holotype. Habitus in dorsal view (256); head in anterodorsal view (257); head and prothorax in lateral view (only bristles on head are shown) (258); antenna (259); aedeagus in ventral (260, 262) and lateral (261, 263) views.