Paraphloeostiba steeli, Shavrin, 2024

Shavrin, Alexey V., 2024, Twenty-one new species of Omaliini from the Papuan Region (Coleoptera: Staphylinidae: Omaliinae), with diagnostic and faunistic notes on some species of the genus Paraphloeostiba Steel, 1960, Zootaxa 5424 (3), pp. 251-307 : 294-296

Paraphloeostiba steeli sp. n.

( Figs 44 , 133–140 )

Type material. Holotype ♂ ( Fig. 44 ; dissected): ‘ NEW GUINEA | Kamin- | dimbit, Main River, Se- | pik, Angoram sub-div., | 12.III.1965, running on | swamp plants in marsh’ <printed>, ‘ R. Hornabrook | BM 1970-232.’ <printed>, ‘ HOLOTYPE | Paraphloeostiba | steeli sp. n. | Shavrin A. V. des. 2024’ <red, printed> ( BMNH).

Paratypes: 1 ♀ (dissected): ‘ NEW GUINEA | Kamindim- | bit, Main River, Sepik, Ango- | ram sub-div., 12.III.1965, | running on swamp plants in | marsh’ <printed>, ‘ R. Hornabrook | BM 1970-232.’ <printed>, ‘ PARATYPE | Paraphloeostiba | steeli sp. n. | Shavrin A. V. des. 2024’ ( BMNH).

Description. Measurements (n=2): HW: 0.25–0.26; HL: 0.21–0.22; OL: 0.12; TL: 0.02; AL (holotype): 0.49; PL: 0.32–0.34; PWmax: 0.55–0.56; PWmin: 0.50–0.52; ESL: 0.52–0.53; EW: 0.64–0.66; MTbL (holotype): 0.30; MTrL (holotype): 0.14 (MTrL 1–4: 0.05; MTrL 5: 0.09); AW: 0.60–0.62; AedL: 0.37; BL: 1.78–1.90 (holotype).

Habitus as in Fig. 44 . Body reddish-brown (holotype with slightly darker abdomen); antennomeres 6–11 brown; mouthparts, antennomeres 1–4 and legs yellow. Head and neck without visible punctures; pronotum with very sparse and fine indistinct punctation, invisible in middle; elytra with dense punctation, distinctly larger and deeper than that on pronotum, slightly finer and sparser in middle; abdominal tergites without visible punctation. Head with very dense and coarse isodiametric microsculpture; microsculpture of pronotum about as that in middle portion of head; elytra with fine isodiametric microreticulation.

Head with moderately deep and wide anteriomedian depressions, slightly broader than long, with short and deep narrow anteocellar foveae about as long as diameter of ocellus; postocular carina absent. Distance between ocelli slightly longer than distance between ocellus and posterior margin of eyes. Antennomeres 6–10 distinctly transverse; antennomere 5 slightly broader than 4, 6 distinctly broader than 5, 7 longer and broader than 6, 8–9 slightly shorter than 7, 10 slightly longer than 9.

Pronotum 1.4–1.6 times as broad as long, twice as broad as head, widest in middle, distinctly more narrowed posteriad than anteriad.

Elytra 1.2 times as broad as long, 1.5–1.6 times as long as pronotum; surface between punctures slightly and longitudinally elevated, stronger in middle.

Abdomen slightly narrower than elytra.

Male. Posterior margin of abdominal tergite VIII truncate ( Fig. 135 ). Posterior margin of abdominal sternite VIII widely and deeply concave ( Fig. 136 ). Aedeagus with wide basal portion, strongly narrowed toward narrow elongate median lobe with very small rounded apex; parameres slightly exceeding apex of median lobe, moderately wide, distinctly broadened apically, with widely rounded apices, with two moderately short apical and preapical setae; internal sac long and moderately wide, without sclerotized structures ( Fig. 133 ). Lateral aspect of the aedeagus as in Fig. 134 .

Female. Posterior margin of abdominal tergite VIII truncate ( Fig. 137 ). Posterior margin of abdominal sternite VIII rounded ( Fig. 138 ). Accessory sclerite short, from widest basal portion gradually narrowed toward rounded apex ( Fig. 139 ). Spermatheca as in Fig. 140 .

Comparative notes. Based on the very narrow median lobe and the parameres, P. steeli sp. n. is similar to P. atramentaria sp. n., P. barclayi sp. n., P. betlephila sp. n. and P. coprophila sp. n. It can be distinguished from all these species by the following morphological features:

from P. atramentaria sp. n. by the smaller and slightly paler body, and slightly longer parameres;

from P. barclayi sp. n. by the darker elytra and the shorter parameres;

from P. betlephila sp. n. by the larger body, the presence of the punctation on the head and the stronger punctation of the pronotum, the shorter elytra and the longer parameres;

from P. coprophila sp. n. by the slightly darker body, the presence of the punctation on the head and the stronger punctation on the pronotum, the shorter elytra and the longer parameres.

From all these species, P. steeli sp. n. can be distinguished by the presence of elevations between punctures on the elytra, distinctly broader apical portions of the parameres and details of the external and internal morphology of the aedeagus.

Distribution. Paraphloeostiba steeli sp. n. is known only from the type locality in Papua New Guinea.

Etymology. The species is named in the memory of the English coleopterologist William Owen Steel (1917– 1969) for his contributions to the knowledge of Omaliinae .

Bionomics. Two specimens were collected in swamp plants in marsh, and one specimen (paratype) was collected in rotting fruit.

Figures

FIGURES 39–44. Habitus of Paraphloeostiba: 39–P. coriacea (Western New Guinea), 40–P. iriana (paratype), 41–P. latissima (paratype), 42–P. guadalcanalensis (paratype), 43–P. margineguttata (holotype), 44–P. steeli (holotype). Scale bars: 1.0 mm.

FIGURES 133–140. Paraphloeostiba steeli: 133–aedeagus, parameral view (holotype), 134–aedeagus, lateral view (holotype), 135–male abdominal tergite VIII, 136–male abdominal sternite VIII, 137–female abdominal tergite VIII, 138–female abdominal sternite VIII, 139–female accessory sclerite, 140–spermatheca. Scale bar: 0.1 mm.