Cephennomicrus nomurai

Jałoszyński, Paweł, 2009, Cephennomicrus Reitter (Coleoptera, Staphylinidae, Scydmaeninae) of Japan and Taiwan: taxonomic notes, ten new species and comparative morphology of nomurai and taiwanensis species groups, Zootaxa 2145, pp. 1-35 : 3-5

nomurai species group

This distinct species group is established herein for Cephennomicrus sharing the following characters: the body relatively large (ca. 1 mm), slender and uniformly covered with relatively long, dense suberect to erect setae, without long setae on margins of the pronotum or elytra; the elytra much broader than the pronotum; the pronotum with a median longitudinal groove and two ante-basal pits connected by a transverse groove, usually an additional, very small pit is located near each hind angle; antennae long and slender, with indistinctly delimited, elongate 3-segmented club; the labrum modified, with membranous basal part and transparent velum along the anterior margin; the mandibles dimorphic, with a short dorsal tooth in males and very long dorsal tooth in females; males with strongly modified head, with a large median protuberance surrounded at each side by an impression; and the aedeagus with the internal armature containing a pair or two pairs of elongate sclerites. The longitudinal groove on the pronotum and modifications of the mouthparts have no counterparts in any other Cephenniini.

This lineage comprises five species known only from the Ryukyus and Taiwan; newly described C. inflatus n. sp. and C. crucifer n. sp., and previously known C. nomurai , C. hobbiti , and C. disjunctus . The latter species was originally described as a subspecies of C. nomurai , but taking into account a disjunctive distribution, placement as a separate species is more appropriate. Therefore, C. nomurai disjunctus is herein elevated to the species rank.

Cephennomicrus nomurai (Jałoszy ń ski & Hoshina, 2003)

( Figs. 1 , 10 , 45, 48 , 53–55 , 56–60 , 66 , 68, 69 , 72, 73 , 76–78 , 82, 84 )

Neseuthia nomurai Jałoszyński & Hoshina, 2003: 49 , Figs. 1, 2 A, 3A, 4C, 5A–C. Cephennomicrus nomurai nomurai ; Jałoszyński, 2008: 33.

Type material. Holotype: JAPAN: Okinawa Pref.: 3, Ishigaki-jima Is., Mt. Omotodake, ( NSMT).

Additional material. JAPAN: Okinawa Pref.: 633, 2ƤƤ, Ishigaki-jima Is., Shiramizu, 3–6.v.2004, FIT, Tomoyuki Tsuru leg. ( PCPJ); 3, same island but Mt. Omotodake, 15–21.iii.2004, FIT, Shûhei Nomura leg. ( NSMT); 3, Iriomote-jima, Airagawa, 19.iii.2004, Shûhei Nomura leg. ( NSMT); 3, Yonaguni-jima Is., Mt. Kubura-dake, 9–12.ix.2004, FIT, Koji & Shiho Arai leg. ( PCPJ).

Distribution. Previously known from two islands of the Ryukyus ( Japan: Okinawa Pref.): Ishigaki-jima and Iriomote-jima; here reported for the first time to occur in Yonaguni-jima, another island of the Sakishima Archipelago.

Remarks. Since the nomurai group proven to be very uniform in external morphology, the primary diagnostic characters defining species are those associated with the aedeagus, especially sclerites of the internal sac. The subapical group of internal sclerites in the aedeagus of C. nomurai ( Fig. 10 ) is symmetrical and relatively complex, composed of two pairs of sclerites, each of a different length, with pointed apices and large external basal structures. A new finding on Yonaguni-jima extends the range of this species westwards, closer to Taiwan.

Cephennomicrus disjunctus (Jałoszy ń ski, S. Arai & K. Arai, 2004) status n. ( Figs. 2 , 11 )

Neseuthia nomurai disjuncta Jałoszyński, S. Arai & K. Arai, 2004: 62 , Figs 2 D–F, 3A, B. Cephennomicrus nomurai disjunctus ; Jałoszyński, 2008: 33.

Type material. Holotype: JAPAN: Okinawa Pref.: 3, Okinawa Is.: Chibanagusuku-ato ( NSMT). Distribution. This species is known only from the type locality in Okinawa Is., the largest island of the Ryukyus ( Japan, Okinawa Pref.).

Remarks. This species is externally nearly identical with C. nomurai ; it can be distinguished on the basis of the unique shape of the internal sclerites of the aedeagus ( Fig. 11 ), which are simpler, longer than those in C. nomurai , with blunt apices, and accompanied with much smaller external basal structures. Modifications of the head of C. disjunctus were studied by scanning electron microscopy (Jałoszyñski et al. 2004: Figs. 3 A, B); they are very similar to those found in all remaining members of the group.

Cephennomicrus hobbiti (Jałoszy ń ski & Hoshina, 2003) ( Figs. 5 , 14 )

Neseuthia hobbiti Jałoszyński & Hoshina, 2003: 53 , Figs. 2 B, 3C, 4D, 5D–F. Cephennomicrus hobbiti ; Jałoszyński, 2008: 33.

Type material. Holotype: JAPAN: Okinawa Pref.: 3, Ishigaki-jima Isl. ( NSMT).

Distribution. Known only from the type locality, Ishigaki-jima, one of the southernmost islands of the Ryukyus ( Japan, Okinawa Pref.).

Remarks. The aedeagus of C. hobbiti differs significantly from other species in this lineage in strongly asymmetrical internal armature ( Fig. 14 ). A pair of long and slender sclerites narrowing toward apices can be recognized, and in the only known specimen they seem to be in a partly extruded state, each accompanied at the base by much smaller and shorter structure. A similar double set of elongate sclerites can be found in all other members of the nomurai group. Cephennomicrus hobbiti is the only species in this lineage that can be easily identified on the basis of external characters: the very large head with strongly raised median convexity and strongly erect vestiture on the elytra.

Figures

FIGURES 1 – 5. Dorsal view of Cephennomicrus (male holotypes). 1, C. nomurai (Jałoszyński & Hoshina). 2, C. disjunctus (Jałoszyński, S. Arai & K. Arai). 3, C. inflatus Jałoszyński. 4, C. crucifer Jałoszyński. 5, C. hobbiti (Jałoszyński & Hoshina). Scale bars: 0.2 mm.

FIGURES 10 – 14. Internal sac of aedeagus of Cephennomicrus in ventral view. 10, C. nomurai (Jałoszyński & Hoshina). 11, C. disjunctus (Jałoszyński, S. Arai & K. Arai). 12, C. inflatus Jałoszyński. 13, C. crucifer Jałoszyński. 14, C. hobbiti (Jałoszyński & Hoshina). Scale bars: 0.05 mm.

FIGURES 45 – 49. Details of C. nomurai (Jałoszyński & Hoshina) (45, 48), C. delicatissimus Jałoszyński (46, 49) and C. tsurui Jałoszyński (47). 45, 46, ventral view of female. 47, head of male in frontal view. 48, 49 head of female in ventral views. Abbreviations: as, antennal socket; ata, anterior tentorial arm; dta, dorsal tentorial arm; fcr, frontoclypeal region; fg, frontal gland; focc, foramen occipitale; gu, gula; lbr, labrum; man, mandible; mllt, median lamella of laminatentorium; occ, occiput; pta, posterior tentorial arm; smen, submentum; tb, tentorial bridge; tllt, transverse lamella of laminatentorium; tm, tempora; v, vertex. Scale bars: 0.2 mm (45, 46); 0.1 mm (47 – 49).

FIGURES 50 – 55. Details of C. delicatissimus Jałoszyński (50, 51), C. tsurui Jałoszyński (52) and C. nomurai (Jałoszyński & Hoshina) (53 – 55). 50, head of male in dorsal view. 51, 52, frontal gland of male in dorsal view. 53, right mandible of male in dorsal view. 54, right mandible of female in dorsal view. 55, frontoclypeal region and labrum in frontal view. Abbreviations: bm, basal membrane of labrum; dt, dorsal tooth of mandible; ma, apex of mandible; mv, marginal velum of labrum; pf, perforated field. Scale bars: 0.05 mm (50, 53 – 55); 0.01 mm (51, 52).

FIGURES 56 – 64. Mouthparts of C. nomurai (Jałoszyński & Hoshina) (56 – 60) and C. delicatissimus Jałoszyński (61 – 64). 56, 61, labrum in dorsal view. 57, right mandible of female in dorsal view. 58, 62, right mandible of male in dorsal view. 59, 63, right maxilla in ventral view. 60, 64, labium in ventral view. Abbreviations: bm, basal membrane of labrum; dt, dorsal tooth of mandible; gal, galea; lac, lacinia; llh, lateral lobe of hypopharynx; ma, apex of mandible; mn, mentum; mv, marginal velum of labrum; pf, perforated field; pm, prementum; ppf, palpifer; sd, suction disc; st, stipes. Scale bars: 0.02 mm.

FIGURES 65 – 67. Details of of C. delicatissimus Jałoszyński (65, 67) and C. nomurai (Jałoszyński & Hoshina) (66). 65, head and prothorax in ventral view. 66, 67, pterothorax in ventral view. Scale bars: 0.2 mm.

FIGURES 68 – 71. Details of C. nomurai (Jałoszyński & Hoshina) (68, 69) and C. delicatissimus Jałoszyński (70, 71). 68, 70, prothorax in ventral view. 69, 71, prothorax in left lateral view. Abbreviations: aph, anterior phragma; hy, hypomeron; lc, lateral carina of pronotum; lg, longitudinal groove of pronotum; pcxc, procoxal cavity; pcxs, procoxal socket; pn, pronotum; pph, posterior phragma; ppr, prosternal process; pst, prosternum. Scale bars: 0.1 mm.

FIGURES 72 – 75. Details of C. nomurai (Jałoszyński & Hoshina) (72, 73) and C. delicatissimus Jałoszyński (74, 75). 72, 74, pterothorax in ventral view; 73, 75, pterothorax in left lateral view. Abbreviations: aest 2, mesanepisternum; aest 3, metanepisternum; epm 2, mesepimeron; epm 3, metepimeron; f 1, meso-metaventral fovea; f 2, mesepimeral fovea; f 3, metaventral-mesepimeral fovea; kes, katepisternum; lfa, lateral furcal arm; lraest 2, lateral ridge of mesanepisternum; lrepm 2, lateral ridge of mesepimeron; mcxc, mesocoxal cavity; mcxs, mesocoxal socket; mt, median tubercle of metaventrite; pavp, posterior arm of mesoventral process; pls, pleural suture; pr, prepectus; v 2, mesoventrite; v 3, metaventrite; vf, vertical foramen; vp 2, mesoventral process; vp 3, metaventral process. Scale bars: 0.2 mm.

FIGURES 76 – 81. Details of C. nomurai (Jałoszyński & Hoshina) (76 – 78) and C. delicatissimus Jałoszyński (79 – 81). 76 – 80, pterothorax in dorsal view. 78, 81, base of right elytron in dorsal view. Abbreviations: alc, alacrista; ap, articulating process of elytral base; aph, anterior phragma; apo, apodeme; asm, adsutural margin of elytron; bf, basal fovea; hd, humeral denticle; lm, lateral margin of elytron; mma, median membranous area; mp, mesal process of elytral base; mph, median phragma; pn 3, metapostnotum; psc 3, premetascutum; sc 2, mesoscutum; sc 3, metascutum; scl 2, mesoscutellum; sss, scuto-scutellar suture; tcsc 2, transverse carina of mesoscutum. Scale bars: 0.1 mm.

FIGURES 82 – 85. Details of C. nomurai (Jałoszyński & Hoshina) (82, 84) and C. delicatissimus Jałoszyński (83, 85). 82, 83, ovipositor in ventral view. 84, 85, male terminalia in dorsal view. Abbreviations: ppr, paraproct; proc, proctiger; s 9, abdominal sternite 9; t 9, abdominal tergite 9; t 10, abdominal tergite 10; vf, valvifer. Scale bars: 0.05 mm.