Lomechusa elegans 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 : 36-38

Lomechusa elegans Chen & Zhou , n. sp.

( Figs. 4–5 )

Type material. Holotype: CHINA: Beijing: male, Mentougou, Xiaolongmen (40°00´N 115°26´E, 1190m), ant nest, 03.IX.2006 Yong-Jie Chen leg. Paratype: 1 female, same data as holotype.

Description. Body length: male 4.74 mm, female 4.98 mm (from apex of head to apex of abdomen).

Measurements. Male. HL: 0.66 mm; HW: 0.84 mm; PL: 1.23 mm; PW: 1.80 mm; EL: 1.32 mm; EW: 1.86 mm. Female. HL: 0.84 mm; HW: 0.87 mm; PL: 1.20 mm; PW: 1.77 mm; EL: 1.20 mm; EW: 1.98 mm.

Body yellowish brown, abdominal tergites V (only apical part), VI and VII darker, abdomen dull.

Head with vertex and frons covered with short soft hairs, directed anteriad, except between eyes where hairs directed irregularly; dorsally near eyes without long hairs; large depression between eyes devoid of tubercles. Eyes black, with some fine short setae between facets, slightly protruded laterally, eye diameter shorter than temple length observed from above. Temples slightly constricted and convergent posteriad.

Antennae ( Fig. 5 e) short, not reaching apex of elytra when deflected backward; each antennomere with dense short hairs. Antennomere 1 twice as long as wide and twice as long as antennomere 2, 3 as long as 2, antennomeres 4–10 nearly moniliform, somewhat elongate, last antennomere about 0.46 mm long, not thicker than 8–10, but slightly shorter than 8–10 combined. Antennomere length ratios (from 1 to 11) are 1.4:0.7:0.7:0.7:0.7:0.7:0.7:0.6:0.6:0.6:1.5.

Pronotum ( Fig. 4 d) transverse, 1.51–1.55 times as broad as long. Dorsal surface with microsculpture, but without pubescence. Disk slightly convex, without medial groove. Lateral depressions large and shallow, with smooth bottom. Anterior margin straight or slightly emarginate, distinctly wider than head, 0.73–0.75 as wide as posterior margin, without narrow elevated strip along anterior margin, punctures distributed along anterior margin and somewhat denser near anterior angles. Lateral margin slightly convergent at basal 3/4. Hypomeron slender. Shallow medial fovea near posterior margin present. Posterior angles short and obtuse.

Elytra measured along suture 0.98–1.07 times as long as pronotum, dorsally weakly convex, densely with short pubescence directed posteriad. Lateral margins convex, maximum width behind the middle, postero-lateral projection totally absent.

Abdominal tergites with basal margin convex; tergites II–V with trichomes at lateral sides of each segment (reduced on tergite V); tergites II–VII with long black setae (denser on II–V), tergites II–V with golden hairs, but absent on VI and VII. Abdominal paratergites III–IV with one black seta each. Chaetotaxy of tergites III–V: 9-11, 9, 5-7. Male tergite VIII as in Fig. 4 a, sternite VIII as in Fig. 4 f, tergites IX–X as in Fig. 4 b. Female tergite VIII as in Fig. 5 a, sternite VIII as in Fig. 5 b, tergites IX–X as in Fig. 5 c.

Aedeagus as in Figs. 4 c, e.

Spermatheca as in Fig. 5 d.

Remarks. The new species can be easily distinguished from other congeneric species by the following characters: (1) some short setae present between facets; (2) antennomeres 4–10 moniliform ( Figs. 5 e); (3) very distinct shape of pronotum ( Fig. 4 d): anterior margin much narrower than posterior.

Host ant. Both specimens of L. elegans were found in the hill-shaped nest of Formica sinensis Wheeler, 1913 made of pine tree needles.

Distribution. China (Beijing).

Etymology. The species epithet is derived from the Latin word " elegans " (elegant).

Figures

FIGURE 4. Details of Lomechusa elegans (male). a— tergite VIII; b— tergites IX – X; c— medial lobe of aedeagus in lateral view; d— pronotum (microsculpture omitted); e— medial lobe of aedeagus in dorsal view; f— sternite VIII. Scale: a, f, 0.25 mm; b, c, 0.2 mm; d, 0.5 mm; e, 0.125 mm.

FIGURE 5. Details of Lomechusa elegans (female). a— tergite VIII; b— sternite VIII; c— tergites IX – X; d— spermatheca; e— antennae (soft hairs omitted). Scale: a – c, 0.2 mm; d, 0.1 mm; e, 0.5 mm.