Labomimus shibatai, Sawada, 1961

Zhang, Yu-Qing & Yin, Zi-Wei, 2019, Three new species of Labomimus Sharp (Coleoptera: Staphylinidae: Pselaphinae) from Taiwan, China, with an updated key for L. shibatai Sawada-group, Zootaxa 4586 (3), pp. 553-561 : 560-561

Key to males of Labomimus shibatai -group

Notes. Eight species are currently placed in this group, including the two new species described here. Members are characterized by the moderately to strongly expanded postgenae of the male. The following key is updated from that of Yin & Li (2015).

1 Antennomere 10 distinctly transverse..................................................................... 2

- Antennomere 10 longer than wider or at least as long as wide.................................................. 4

2 Antennomeres 9 and 10 obliquely conjoined ( Yin & Li 2012: fig 3A). Parameres of aedeagus narrow throughout entire length in ventral view ( Yin & Li 2012: fig 3L). [ China: Hubei, Shaanxi]............................ L. dabashanus Yin & Li

- Antennomeres 9 and 10 conjoined near or at middle ( Fig. 4A ; Yin et al. 2013b: fig. 16). Parameres of aedeagus strongly expanded at apical half in ventral view.................................................................... 3

3 Postgenae as broad as width across eyes (Yin et al. 2013b: fig. 2). Antennomere 9 elongate, approximately cylindrical, without long pubescence on mesal margin (Yin et al. 2013b: fig. 16). Pronotum lack median longitudinal sulcus (Yin et al. 2013b: fig. 2). [ China: Sichuan]........................................................... L. jiudingensis Yin & Nomura

- Postgenae broader than width across eyes ( Fig. 3A ). Antennomere 9 expanded and with long pubescence on mesal margin ( Fig. 4A ). Pronotum with distinct median longitudinal sulcus ( Fig. 3A ). [ China: Taiwan]........... L. dilaticeps sp. nov.

4 Lateral expansion of postgenae weakly developed, excavation small ( Yin & Li 2015, Fig. 3C ). Apical portion of mesotibiae slightly concave on mesal margin ( Yin & Li 2015: fig. 3C). [ Japan: Honshu]......................... L. reitteri Sharp

- Lateral expansion of postgenae strongly developed, with large excavation. Apical portion of mesotibiae not concave on mesal margin.............................................................................................. 5

5 Antennomeres 9–10 strongly modified, antennomere 11 with acute anterolateral angle ( Yin & Li 2012, Fig 8A). Pronotal disc smooth ( Yin & Li 2012: fig 6B). [ China: Shaanxi].......................................... L. schuelkei Yin & Li

- Antennomeres 9–10 enlarged but not modified, antennomere 11 lacks acute anterolateral angle. Pronotum roughly punctured.................................................................................................... 6

6 Antennomere 9 distinctly broader than 10 ( Sawada 1961: Fig. 9). [ Japan: Honshu, Shikoku]........... L. shibatai Sawada

- Antennomere 9 as wide as 11 ( Fig. 5A ; Yin et al. 2013a: fig. 6A)................................................ 7

7 Pronotal median longitudinal sulcus faint (Yin et al. 2013a: fig. 4B). Metaventral processes short and narrowed at apex (Yin et al. 2013a: fig. 6C). Parameres of aedeagus not extending beyond apex of median lobe (Yin et al. 2013a: fig. 6I–K). [ China: Sichuan]............................................................. L. sichuanicus Hlaváč, Nomura & Zhou

- Pronotum with distinct median longitudinal sulcus ( Fig. 3B ). Metaventral processes long and broadened at apex ( Fig. 5C ). Parameres of aedeagus extending beyond apex of median lobe ( Fig. 5 I–K). [ China: Taiwan]........... L. sugayai sp. nov.

Figures

FIGURE 3. Dorsal habitus of Labomimus dilaticeps (A), and L. sugayai (B). Scale bar: 1.0 mm.

FIGURE 4. Diagnostic features of Labomimus dilaticeps, male. A. Antennal club. B. Pronotum. C. Metaventral process, in lateral view. D. Protrochanter and profemur. E. Apex of protibia. F. Mesotrochanter and mesofemur. G. Metatrochanter and metafemur. H. Sternite IX. I–K. Aedeagus, in dorsal (I), lateral (J), ventral (K) view. Scale bar: A, B, D, F, G = 0.3 mm; C, I, J, K = 0.2 mm; H = 0.1 mm; E = 0.05 mm.

FIGURE 5. Diagnostic features of Labomimus sugayai, male. A. Antennal club. B. Pronotum. C. Metaventral process, in lateral view. D. Protrochanter and profemur. E. Apex of protibia. F. Mesotrochanter and mesofemur. G. Metatrochanter and metafemur. H. Sternite IX. I–K. Aedeagus, in dorsal (I), lateral (J), ventral (K) view. Scale bar: A, B, D, F, G = 0.3 mm; C, I, J, K = 0.2 mm; H = 0.1 mm; E = 0.05 mm.