Lomechusa brevicornis 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 : 33-34

Lomechusa brevicornis Chen & Zhou , n. sp.

( Fig. 2 )

Type material. Holotype: CHINA: Beijing: male, Mentougou, Xiaolongmen (40°00´N 115°25´E, 1140m), ant nest, 28.VIII.2006, Yong-Jie Chen leg.

Description. Body length: 5.70 mm (from apex of head to apex of abdomen).

Measurements. HL: 0.90 mm; HW: 0.90 mm; PL: 1.17 mm; PW: 1.80 mm; EL: 1.32 mm; EW: 2.10 mm.

Body dark brown, eyes black, elytra lighter; head, abdominal tergites V, VI and VII (only the anterior part) black, abdomen glossy.

Head without punctation, except between eyes where sparsely covered with short hairs directed posteriad; shallow depression between eyes devoid of tubercles. Eyes without seta between facets, strongly protruded laterally, eye diameter longer than temple length observed from above. Temples distinctly constricted and convergent posteriad.

Antennae ( Fig. 2 f) short, not reaching apex of elytra when deflected backward; each antennomere with short hairs (not shown in Fig. 2 f) and 2–4 stout setae. Antennomere 1 twice as long as wide, and twice as long as antennomere 2, 3 1.3 times as long as 2, antennomeres 4–7 and 9–10 each elongate and with truncate apex, antennomere 8 oblique at the apex, last antennomere about 0.52 mm long, as wide as 8–10, but distinctly shorter than 8–10 combined. Antennomere length ratios (from 1 to 11) are 2:1:1.3:0.7:0.8:0.9:0.9:1:1:1:2.1.

Pronotum ( Fig. 2 b) transverse, 1.60 times as broad as long. Dorsal surface with dense microsculpture but without pubescence. Disk flat, without medial groove. Lateral depressions rounded, deep and glossy. Anterior margin straight, distinctly wider than head, 0.83 as wide as posterior margin, narrow elevated strip along anterior margin present. Lateral margin constricted at basal 1/3. Hypomeron slender. Medial fovea near posterior margin absent. Posterior angles acute and protruding.

Elytra measured along suture 1.11 times as long as pronotum, dorsally weakly convex, with short pubescence directed postero-laterally but laterally in apical part. Lateral margin convergent in anterior 1/4, parallelsided in posterior 3/4. Postero-lateral projection indistinct.

Abdominal tergites with basal margin convex; tergites II–V with trichomes at lateral sides of each segment, tergites II–VI with long golden hairs directed posteriad, tergite VII smooth. Abdominal paratergites III– IV with one black setae each. Chaetotaxy of tergites III–V: 7, 7, 3. Female tergite VIII as in Fig. 2 a, sternite VIII as in Fig. 2 e, tergites IX–X as in Fig. 2 d.

Spermatheca as in Fig. 2 c.

Remarks. The new species is similar to L. dvoraki Hlaváč , but can be easily distinguished from the later and all other described species of the genus by the following characters: (1) eye diameter longer than temple length observed from above; (2) temples distinctly convergent posteriad; (3) antennae ( Fig. 2 f) shorter, each antennomere with 2–4 setae, and antennomere 8 oblique at the apex.

Host ant. The only known specimen of this L. brevicornis was found beside a stump in the nest of Formica sinensis Wheeler, 1913 made up of litter.

Distribution. China (Beijing).

Etymology. The species epithet refers to short antennae of this species and is derived from the Latin words " brevis " (short) and " cornu "(horn).

Figures

FIGURE 2. Details of Lomechusa brevicornis. a— tergite VIII; b— pronotum (microsculpture omitted); c— spermatheca; d— tergites IX – X; e— sternite VIII; f— antennae (soft hairs omitted). Scale: a, 0.3 mm; b, f, 0.5 mm; c, 0.1 mm; d, 0.2 mm; e, 0.25 mm.