Zyras (Zyras) reductus, Assing, 2019

Assing, Volker, 2019, On the Lomechusini fauna of the Palaearctic and Oriental regions. XXVI. New species, a new synonymy, and additional records (Coleoptera: Staphylinidae: Aleocharinae), Beiträge Zur Entomologie = Contributions to Entomology 69 (1), pp. 33-70 : 66-67

Zyras (Zyras) reductus spec. nov.

urn:lsid:zoobank.org:act:15761BF9-31AA-4B92-A7A5-8C3535DF876C

(Figs 71–74,160–162)

Type material: Holotype: “ PHILIPPINES: Mindanao , Sitio Bitaugan, Kawa-kawa River, 300 m, 6°46'31"N, 126°08'41"E, stream bank, wet litter, debris, dead wood, 24–26.III.2018, leg. Shavrin / Holotypus Zyras reductus sp. n., det. V. Assing 2018” (cAss).

Etymology: The specific epithet is the past participle of the Latin verb reducere and alludes to the completely reduced hind wings.

Description: Body length 6.2 mm; length of forebody 2.7 mm.Habitus as in Fig. 71. Coloration:forebody brown; abdomen dark-brown with the anterior margins and the narrow posterior margins of the segments reddish-yellow and with the postero-median portions of tergites V and VI blackish; legs yellowish; antennae pale reddish-brown with antennomere XI dark-yellowish and the basal three antennomeres pale-reddish; maxillary palpi yellow.

Head (Fig. 72) 1.1 times as broad as long; punctation sparse and very shallow, median portion extensively impunctate. Eyes strongly convex, longer than postocular region in dorsal view. Antenna (Fig. 73) 2.2 mm long and rather slender; antennomeres IV–V weakly oblong, VI approximately as long as broad, VII–X weakly oblong, X much less than 1.5 times as broad as long, and XI approximately as long as the combined length of IX and X.

Pronotum (Fig. 72) approximately as broad as long and 1.07 times as broad as head, broadest at anterior angles, rather strongly convex in cross–section; lateral margins not sinuate in dorsal view; posterior angles obtusely marked; punctation rather coarse, moderately sparse, and somewhat irregularly distributed; impunctate median band moderately broad.

Elytra (Fig. 72) conspicuously short, 0.55 times as long as pronotum, distinctly dilated posteriad; humeral angles completely obsolete; punctation moderately dense, very coarse, and sharply defined. Hind wings completely reduced. Legs long and slender; metatarsomere I slender, nearly as long as the combined length of II–IV.

Abdomen (Fig. 74) distinctly broader than elytra, with rather deep anterior impressions on tergites III–V; anterior impressions of tergites III–V each with a transverse row of distinct non-setiferous punctures, with few lateral setiferous punctures on either side, and with six (tergites III and IV) or eight (tergite V) setiferous punctures bearing long black setae at or near posterior margin; tergite VI with a transverse row of non-setiferous punctures anteriorly, with few lateral setiferous punctures on either side and with ten setiferous punctures at or near posterior margin; tergite VII with a transverse band of rather sparse non-setiferous punctures anteriorly and with two highly irregular transverse series of setiferous punctures posteriorly, posterior margin with an indistinct rudiment of a palisade fringe; tergite VIII with setiferous punctation only in posterior third, posterior margin strongly convex.

: sternite VIII strongly produced posteriorly, posterior margin truncate in the middle; median lobe of aedeagus approximately 0.75 mm long and shaped as in Figs 160–161 ; paramere ( Fig. 162 ) 0.9 mm long, apical lobe rather short, flattened and apically broadly convex.

: unknown.

Comparative notes: Based on the slender habitus, the slender antennae, the strongly convex pronotum (crosssection), the punctation pattern of the abdomen, and the morphology of the aedeagus (shape of median lobe and of apical lobe of paramere), this conspicuous species is closely related to Z. nitens CAMERON, 1944 , Z. glabricol- lis SCHEERPELTZ, 1965, Z. truncatus ASSING, 2017 , and allied species. It is readily distinguished from all other species of Zyras sensu strictu by much shorter elytra alone. The only other species that is at least close to this condition is Z. kinabaluensis Pace, 2008 from Borneo, from which Z. reductus is distinguished by even shorter elytra ( Z. kinabaluensis : elytra 0.65 times as long as pronotum), larger body size ( Z. kinabaluensis : length of forebody 2.4 mm), less slender antennae with a longer antennomere XI, larger and more convex eyes, a broader abdomen, and by the shape of the aedeagus. For illustrations of Z. kinabaluensis see ASSING (2017c) and PACE (2008).

Distribution: The type locality is situated in Davao Oriental Province in the southeast of Mindanao, South Philippines. The holotype was collected by sifting wet litter between stones, wet debris, and dead wood accumulated near the Kawa-kawa river at an altitude of 300 m.

Figures

Figs 145–165:Drusilla spiniventris(145–147), D. breviuter(148–152), Pheidologitonetes biplicatus (153–154), Zyras conlectus (155– 157), Z. hetzeli (158–159), Z. reductus(160–162), andZ. shavrini(163–165): male tergite VIII (145, 148); median lobe of aedeagus in lateral and in ventral view (146–147, 149–150, 153–156, 158–161, 163–164); female tergite VIII (151); spermatheca (152); paramere (157, 162, 165). Scale bars: 145–151, 153–165: 0.2 mm; 152: 0.1 mm.