Scaphoxium lobatum, Löbl, 2022

Löbl, Ivan, 2022, Supplement to the knowledge of the Scaphidiinae (Coleoptera: Staphylinidae) of the Moluccas, Revue suisse de Zoologie 129 (1), pp. 103-118 : 117

Scaphoxium lobatum sp. nov.

Figs 28, 29

Material examined: Holotype; MHNG; male; MALUK: Aru Isl. , Wokam, 5 km E Mt. Sungai, 22.8.1981, D. Agosti F91936 .

Etymology: The species epithet is a Latin adjective meaning lobed.

Diagnosis: Body-length 1.35 mm; elytral punctation well delimited; hypomeron with longitudinal ridge; mesoventrite and metaventrite grooved mesally; lateral parts of the metaventrite bearing coarse punctures; submesocoxal area as long as shortest interval to metacoxa; abdomen with punctulate microsculpture; aedeagus as Figs 28, 29 , with parameres broadly lobed at level of tip on median love, slightly narrowed posterior of lobe, internal sac lacking distinct sclerites and without scale-like or spine-like structures.

Description: Length 1.35 mm, width 0.67 mm, dorsoventral diameter 0.73 mm. Body uniformly dark brown, appendages lighter. Length/width ratios of antennomeres as: III 15/6: IV 15/6: V 25/6: VI 23/7: VII 38/10: VIII 28/8: IX 35/11: X 35/12: XI 43/13. Pronotal punctation dense and fine, distinct at 50 times magnification. Tip of scutellum exposed. Sutural striae starting posterior of basal fourth of elytra, evanescent in anterior 0.20 mm of elytral length. Elytral punctation and pubescence dense, visible at 25 times magnification, consist of sharply delimited punctures. Hypomeron very finely punctate on somewhat convex upper part, impunctate on flattened lower part; lower and upper parts separated by ridge extended anteriorly to level of procoxal mid-length. Mesoventrite grooved mesally. Mesanepisternum very finely punctate. Metaventrite grooved mesally, in middle very finely punctate. Lateral parts of metaventrite with punctation coarse and dense near submesocoxal lines, with punctures to parts larger than puncture intervals; punctation becoming sparser and fines laterad, areas along metanepisterna impunctate. Submesocoxal lines strongly arcuate, finely punctate. Submesocoxal areas 0.05 mm, about as long as shortest intervals to metacoxae. Metanepisterna not fused, with straight, finely punctate suture nearly touching margin of metepimera. Visible abdominal segments with distinct punctulate microsculpture. Exposed ventrites with very fine punctation, coarse row of basal punctures of ventrite I excepted.

Male characters: Protarsomeres I to III hardly widened. Aedeagus ( Figs 28, 29 ) 0.51 mm long. Parameres each with large, rounded lobe at level of tip of median lobe, narrow and weakly bent posterior lobe, internal sac with plate-like structure, lacking spines or scales.

Habitat: Secondary/primary forest on limestone, rather dry leaf litter; understory Pandanus palms.

Distribution: Indonesia: Moluccas, Aru Islands.

Remarks: This species resembles S. bilobum Löbl, 2015 from Lombok which shares the shape of the parameres and the coarse punctation on lateral parts of the metaventrite. These two species differ in elytral punctation which is notably denser and consist of sharply delimited punctures in S. lobatum . The more relevant feature of S. lobatum is the internal sac lacking two pairs of strongly sclerotized pieces. The antennomeres III and IV appear slightly shorter in S. lobatum , a character not to be used as diagnostic until more material available to assess its variability more reliably. The length of the antennomere VI of S. bilobum was given in the original description as equal to that of the antennomere VII by error ( Löbl, 2015b: 117), it is equal to that of the antennomere V.

Figures

Figs 23-29. Scaphisoma donati sp. nov. (23) Parameres in ventral view, scale bar = 0.2 mm. Figs 24-27. Scaphobaeocera plana sp. nov. (24, 25) Aedeagus in dorsal and lateral views, scale = 0.1 mm. (26) Paramere in ventral view, scale = 0.05 mm. (27) Apical part of median lobe, in lateral view, scale = 0.05 mm. Figs 28, 29. Scaphoxium lobatum sp. nov. (28) Aedeagus in ventral view, scale = 0.1 mm. (29) Apex of median lobe with extruded internal sac and right paramere, in dorsal view, scale = 0.05 mm.