Euconnus (Rhomboconnus) rhombocartianus, Jałoszyński, 2017

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

Euconnus (Rhomboconnus) rhombocartianus sp. n.

( Figs 5 , 13 , 33–34, 41–42, 53)

Holotype: Panama (Guna Yala Province): ♂, two labels: " PANAMA, Carti / 20/04/2014 / 9,320°N, 79,00°W, fruits on / litter layer, leg. Tim Struyve" [white, printed], " EUCONNUS / ( RHOMBOCONNUS ) / rhombocartianus m. / P. Jałoszyński, '17 / HOLOTYPUS " [red, printed] ( MNHW).

Diagnosis. BL <2 mm; head with sparse but long suberect setae, pronotum with a few long and sparse setae anterolaterally, elytra with very sparse, short but distinct suberect setae; tempora strongly narrowing posteriorly and their very short posterior portion which is bent mesally is not visible in dorsal view; pronotum broadest between middle and posterior third and strongly narrowed posteriorly and anteriorly; pronotal base lacking transverse groove, with one pair of very small and shallow, puncture-like lateral pits; parameres not broadened in subapical region.

Description. Body of male ( Fig. 5 ) strongly convex, elongate, with moderately long appendages, BL 1.93 mm; cuticle glossy, uniformly dark brown, vestiture slightly lighter than cuticle.

Head ( Fig. 13 ) slender and strongly narrowing posteriorly, broadest at eyes, HL 0.45 mm, HW 0.33 mm; vertex and frons confluent, evenly and weakly convex except frons in front of eyes which steeply declines anteriorly, posterior margin of vertex projecting posteriorly as subrectangular lobe about as broad as 1/3 of HW; tempora just behind eyes slightly concave, then nearly straight, with extremely short, barely noticeable posterior portion bent posteromesally visible only in lateral or dorsolateral view; supraantennal tubercles barely marked; eyes large, finely faceted and strongly projecting from silhouette of head. Punctures on vertex and frons very fine and inconspicuous; setae sparse but long and suberect, posterior portion of each temple and posterior margin of vertex with sparsely distributed long bristles. Antennae slender, AnL 1.23 mm; all antennomeres except III elongate, III slightly transverse; antennomeres VII–XI forming indistinctly delimited club, antennomere XI distinctly shorter than IX and X combined, ~2.2 times as long as broad, slightly flattened.

Pronotum ( Fig. 13 ) in dorsal view broadest between middle and posterior third and strongly narrowing anteriorly and posteriorly, PL 0.45 mm, PW 0.53 mm; base lacking transverse groove, with one pair of very small and shallow lateral pits. Punctures as fine as those on frons and vertex, pronotal disc largely asetose except for sparse long and suberect setae in anterolateral regions and lateral bristles.

Elytra suboval, broadest near middle, EL 1.03 mm, EW 0.83 mm, EI 1.24; apices separately rounded. Punctures on elytral disc inconspicuous; setae short but distinct, very sparse and suberect.

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

Aedeagus (Figs 33–34, 41–42) stout, AeL 0.38 mm, in ventral view drop-shaped with lateral margins gradually convergent toward apex; endophallus with three long and one short sclerites ( Fig. 53 ), of which the longest one has its apical portion rapidly narrowed and curved, forming a narrow hook; parameres not broadened in subapical region.

Female. Unknown.

Distribution. Central Panama, Guna Yala Province.

Etymology. Combination of the subgeneric name Rhomboconnus and the town name Puerto de Carti.

Remarks. Euconnus rhombocartianus is a remarkable species with strikingly slender head strongly narrowing posteriorly and eyes strongly projecting from its silhouette; these characters are unique among Rhomboconnus .

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).