Lomechusa seticornis Chen & Zhou

Chen, Yong-Jie & Zhou, Hong-Zhang, 2007, Taxonomy of the myrmecophilous genus Lomechusa (Coleoptera: Staphylinidae: Aleocharinae: Lomechusini) from China, Zootaxa 1606, pp. 29-39 : 34-36

Lomechusa seticornis Chen & Zhou , n. sp.

(Fig. 3)

Type material. Holotype: CHINA: Hunan: female, Yizhang, ant nest, 08.VI.2004, Jian-Hua Huang leg. Description. Body length: 5.25 mm (from apex of head to apex of abdomen).

Measurements. HL: 0.75 mm; HW: 0.78 mm; PL: 1.05 mm; PW: 1.47 mm; EL: 1.17 mm; EW: 1.56 mm. Body dark brown, head including eyes black, pronotum reddish brown, abdominal tergites V (only the basal part) and VI almost black, abdomen dull.

Head with vertex and frons covered with short soft hairs directed anteriad, dorsally near eyes without hairs, large shallow depression between eyes devoid of tubercles. Eyes without setae between facets, strongly protruded laterally, eye diameter longer than temple length observed from above. Temples straight and convergent posteriad.

Antennae (Fig. 3g) short, not reaching apex of elytra when deflected backward; each antennomere with dense hairs (not shown in Fig. 3g) and a row of stout black setae at apex. Antennomere 1 twice as long as wide and twice as long as antennomer 2, 3 1.2 times as long as 2, antennomeres 4–6 and 8–10 each elongate and with truncate apex, antennomere 7 oblique at apex, last antennomere 0.38 mm long, as thick as 8–10, and distinctly shorter than 8–10 combined. Antennomere length ratios (from 1 to 11) are 3:1.4:1.7:1.4:1.3:1.4:1.8:1.3:1.5:1.4:3.2.

Pronotum (Fig. 3f) transverse, 1.53 times as broad as long. Dorsal surface smooth. Disk flat, with a shallow medial groove. Lateral depressions (in lateral portion of pronotal disk) large, deep and smooth, partially visible from above. Anterior margin straight, as wide as head, 0.92 as wide as posterior margin, narrow elevated strip along anterior margin present. Lateral margin slightly convergent at basal 4/5. Hypomeron slender. Medial fovea near posterior margin absent. Posterior angles short and obtuse.

Elytra measured along suture 1.11 times as long as pronotum, dorsally weakly convex, with fine golden hairs directed postero-laterally, each with a shallow depression near lateral margins. Lateral margins convergent in anterior 1/4, parallel-sided in posterior 3/4. Postero-lateral projection well defined.

Abdominal tergites with basal margin convex; tergites II–V with trichomes at lateral sides of each segment (reduced on tergite V); tergites II–VI with hairs directed posteriad, tergites VII smooth. Abdominal paratergites III each with one black seta, but abdominal paratergite VI with only one black seta. Chaetotaxy of tergites III–V: 5, 3, 4. Male tergite VIII as in Fig. 3a, sternite VIII as in Fig. 3b, tergites IX–X as in Fig. 3d.

Aedeagus as in Fig. 3c, e.

Remarks. The new species can be distinguished from all other known congener species by the following characters: (1) the depression in the lateral portion of the pronotal disk is partially visible from above; (2) each antennomere covered with dense hairs and in the apical part with a row of stout setae; (3) eye diameter longer than temple length.

Host ant. Unknown.

Distribution. China (Hunan).

Etymology. The species epithet refers to pubescent antennae of this species and is derived from the Latin words " seta " (stout hair) and " cornu " (horn).