Aenictoides derivata, Assing, 2016

Assing, Volker, 2016, On some Lomechusini of the Palaearctic and Oriental regions (Coleoptera: Staphylinidae: Aleocharinae), Beiträge Zur Entomologie = Contributions to Entomology 66 (1), pp. 13-111 : 109

Aenictoides derivata spec. nov.

( Figs 190–196 , 466–471 )

Type material: Holotype ♂: “ Thailand [3] – Doi Inthanon , Mae Aeb stream , 18°32'N, 98°36'E, 550 m, stream bank, 20.XII.2013, leg. Ob / Holotypus ♂ Aenictoides derivata sp. n. det. V. Assing 2015” ( cAss).

Etymology: The specific epithet is the past participle of the Latin verb derivare and alludes to the conspicuously derived habitus, punctation, antennae, and legs.

Description: Body length 4.1 mm; length of forebody 1.9 mm. Coloration: head bicoloured, posteriorly blackish, frons, clypeus, and mouthparts reddish; pronotum reddish-brown; elytra reddish-brown, with the posterolateral portions extensively dark-brown; abdomen yellowish-red; legs yellowish with the dilated apical portions of the meso- and metafemora and parts of the metatibiae and metatarsi weakly to distinctly infuscate; antennae reddish with antennomeres I and XI brown.

Head ( Figs 190–191 ) distinctly transverse, 1.3 times as broad as long, broadest across eyes; posterior portion of trapezoid shape, i.e., lateral margins behind eyes converging, straight, posterior angles rather marked, and posterior margin truncate; posterior constriction 0.37 times as broad as head; impressed median dorsal portion with a transverse row of four coarse punctures with puncturoid microsculpture, anterior to this row with a pair of punctures; posteriorly with an oblong impression with puncturoid microsculpture reaching posterior margin; median dorsal portion glossy, except for the impressions and elevations. Antenna ( Fig. 192 ) 1.4 mm long; antennomeres II weakly oblong, III approximately as long as broad, IV–X approximately twice as broad as long, and XI oval, shorter than the combined length of IX and X.

Pronotum ( Figs 190–191 ) 1.02 times as long as broad and 0.9 times as broad as head, distinctly narrowed anteriad; posterior angles marked; lateral elevations glossy, median impressions with puncturoid microsculpture; lateral elevations with sparse granulose setiferous punctation.

Elytra ( Figs 190–191 ) 0.84 times as long as pronotum; humeral angles marked; punctation very coarse and dense (separated by narrow ridges) in anterior and sutural portions, less dense and less coarse on remainder of disc. Scutellum large, with dense puncturoid microsculpture and matt. Hind wings present. Metatarsomere I slightly longer than the combined length of II and III.

Abdomen ( Figs 194–196 ) as characterized in the description of the genus; posterior margin of tergite VII with palisade fringe.

♂: posterior margin of tergite VIII weakly, but distinctly concave; posterior margin of sternite VIII convex; median lobe of aedeagus ( Figs 468–469 ) 0.68 mm long, very slender, with bisinuate ventral process in lateral view; internal sac without sclerotized structures; paramere ( Figs 470–471 ) 0.53 mm long, broad, and of derived shape.

♀: unknown.

Comparative notes: Aenictoides derivata is readily distinguished from all other species of Lomechusini by its conspicuous habitus and other derived external characters alone.

Distribution and natural history: The type locality is situated in Doi Inthanon, Chiang Mai province, North Thailand. The holotype was sifted from litter between rocks at an altitude of 550 m. The species is most likely associated with ants of the genus Aenictus (Maruyama, e-mail 6 July, 2015).

Figures

Figs 181–196. Zyrasporrectus(181–183),Z.wunderlei(184–186),Pedinopleurusnotabilis (187–189),andAenictoides derivatus (190– 196): forebody (181, 184, 187, 190); antenna (182, 185, 188, 192); abdomen (183, 186, 194); tergites IX–X (189); forebody in lateral view (191); thorax in ventral view (193); abdomen in lateral view (195); abdomen in ventral view (196). Scale bars: 181–188, 190–196: 1.0 mm; 189: 0.5 mm.

Figs 459–471. Zyras porrectus (459–460), Z. wunderlei (461–465), and Aenictoides derivata (466–471): median lobe of aedeagus in lateral and in ventral view (459–462, 468–469); paramere (463, 470); male tergite VIII (464); male sternite VIII (465); maxilla (466); labium (467); apical lobe of paramere (471). Scale bars: 459–466, 468–470: 0.2 mm; 467, 471: 0.1 mm.