Euconnus (Rhomboconnus) rhomboimitator, Jałoszyński, 2017

Jałoszyński, Paweł, 2017, Euconnus (Rhomboconnus) of Panama (Coleoptera, Staphylinidae, Scydmaeninae), Zootaxa 4323 (1) : -

Euconnus (Rhomboconnus) rhomboimitator sp. n.

( Figs 8 , 16 , 39–40, 47–48, 56)

Holotype: Panama (Veraguas Province): ♂, two labels: " PANAMA, Rusia de Quebro / 27/07/2014 / 7,458°N, 80,925°W, border / mangrove, leg. Tim Struyve" [white, printed], " EUCONNUS / ( RHOMBOCONNUS ) / rhomboimitator m. / P. Jałoszyński, '17 / HOLOTYPUS " [red, printed] ( MNHW). Paratype: ♂, " PANAMA, near Miramar / 30/07/2014 / 8,95- 8,99°N / 82,19- 82,24°W, / car-net, leg. Tim Struyve" [white, printed] ( TSCB).

Diagnosis. BL <2 mm; head and pronotum virtually asetose (except for bristles and a few moderately long setae distributed in anterolateral portions of pronotum), elytra with sparse but well-visible suberect setae; tempora strongly narrowing posteriorly with very short but in dorsal view well-visible posterior portions bent mesally; pronotum broadest in posterior third and distinctly narrowed posteriorly and anteriorly; pronotal base with shallow and diffuse transverse groove connecting a pair of small and shallow lateral pits; parameres distinctly broadened in subapical region; median endophallic sclerite (i.e., the shortest one) with straight distal portion.

Description. Body of male ( Fig. 8 ) strongly convex, elongate, with moderately long appendages, BL 1.90– 1.98 mm; cuticle glossy, uniformly dark brown, vestiture slightly lighter than cuticle.

Head ( Fig. 16 ) strongly narrowing posteriorly, broadest at eyes, HL 0.43 mm, HW 0.35–0.36 mm; vertex and frons confluent, evenly and relatively weakly convex except frons in front of eyes which steeply declines anteriorly, posterior margin of vertex projecting posteriorly as subtrapezoidal lobe slightly broader than 1/3 of HW; tempora indistinctly (barely noticeably) convex with short but in dorsal view well-visible posterior portions bent mesally; supraantennal tubercles barely marked; eyes large, finely faceted and weakly projecting from silhouette of head. Punctures on vertex and frons very fine and inconspicuous; setae extremely short and recumbent, barely discernible, posterior portion of each temple with small tuft of thick and relatively short bristles. Antennae slender, AnL 1.20 mm; all antennomeres except III elongate, III indistinctly transverse; antennomeres VII–XI forming indistinctly delimited club, antennomere XI only slightly longer than X, ~1.7 times as long as broad, indistinctly flattened.

Pronotum ( Fig. 16 ) in dorsal view broadest near posterior third and strongly narrowing anteriorly, weakly so posteriorly, PL 0.43 mm, PW 0.48–0.50 mm; base with shallow and diffuse transverse groove connecting a pair of small and shallow lateral pits. Punctures and setae similar to those on frons and vertex, except for a few moderately long setae distributed in anterolateral portions of disc and lateral bristles.

Elytra suboval, broadest slightly anterior to middle, EL 1.05–1.13 mm, EW 0.83–0.86 mm, EI 1.27–1.30; apices separately rounded. Punctures on elytral disc inconspicuous; setae moderately sparse, long and suberect, well-visible.

Legs moderately long and slender; protrochanter with distinctly projecting distoventral corner forming small pointed tooth.

Aedeagus (Figs 39–40, 47–48) stout, AeL 0.38 mm, in ventral view drop-shaped with sides in subapical region rapidly and strongly narrowed; endophallus with two long and two distinctly shorter sclerites ( Fig. 56 ), of which the two longest ones have their apices pointed; parameres distinctly broadened in subapical region.

Female. Unknown.

Distribution. Southern-central Panama, Province Veraguas, and western Panama, Bocas del Toro Province.

Etymology. Combination of the subgeneric name Rhomboconnus and imitator, to underline its inconspicuous body shape and similarity to other species.

Remarks. Euconnus rhomboimitator is an inconspicuous Rhomboconnus that can be easily confused with E. rhombopanamensis . It differs in distinctly denser and longer elytral setae and the endophallic sclerites, as given in Remarks for the latter species.

Figures

FIGURES 1 – 8. Dorsal habitus of Rhomboconnus species, males. Euconnus plaumannioloides sp. n. (1); E. timstruyvei sp. n. (2); E. silvafortunensis sp. n. (3); E. rhombopanamensis sp. n. (4); E. rhombocartianus sp. n. (5); E. meteti sp. n. (6); E. rhombomiramaranus sp. n. (7); E. rhomboimitator sp. n. (8).

FIGURES 9 – 16. Head and pronotum of Rhomboconnus species, males, in strictly dorsal view. Euconnus plaumannioloides sp. n. (9); E. timstruyvei sp. n. (10); E. silvafortunensis sp. n. (11); E. rhombopanamensis sp. n. (12); E. rhombocartianus sp. n. (13); E. meteti sp. n. (14); E. rhombomiramaranus sp. n. (15); E. rhomboimitator sp. n. (16).

FIGURES 49 – 56. Endophallic sclerites of Rhomboconnus species in ventral view (not to the same scale). Euconnus plaumannioloides sp. n. (49); E. timstruyvei sp. n. (50); E. silvafortunensis sp. n. (51); E. rhombopanamensis sp. n. (52); E. rhombocartianus sp. n. (53); E. meteti sp. n. (54); E. rhombomiramaranus sp. n. (55); E. rhomboimitator sp. n. (56).