Glischrochilus (Librodor) forcipatus ( Fairmaire, 1889 )

Jelínek, Josef, Lasoń, Andrzej & Hájek, Jiří, 2012, Glischrochilus (Librodor) forcipatus (Fairmaire, 1889) rediscovered (Coleoptera: Nitidulidae), Zootaxa 3202, pp. 58-64 : 60-62

Glischrochilus (Librodor) forcipatus ( Fairmaire, 1889)

( Figs 1 , 5, 9 )

Librodor forcipatus Fairmaire, 1889: 12 .

Glischrochilus forcipatus: Grouvelle 1913: 188 . Glischrochilus (Librodor) forcipatus: Jelínek 1975: 140 .

Type locality. “Mou-Pin” [ China, Sichuan province, Baoxing, ca. 30°23´N, 102°50´E].

Material studied. CHINA: SICHUAN PROV.: 1 spec., “Mou-Pin” ( MNHN) [Holotype, examined by senior author (JJ) in 1975]; 3 spec., Qingcheng Hou Shan Mts., 70 km W Chengdu, 1435 m, 4.vi.2004, S. Murzin lgt. ( ALBC, NMPC, USMB); 1 spec., Minshan Mts., 60 km E of Songpan, 1000 m, 1–10.vii.2004, V. Patrikeev lgt. ( ALBC).

Redescription. Body oblong oval, convex, black, each elytron with two yellowish spots: three-branched basal spot situated at inner side of humeral bulge and transverse zigzag band at two thirds of elytral length, reaching neither suture nor lateral margin. Vestiture of very thin and short indistinct grey recumbent setae not reaching the base of the following ones. Setae at sides of pronotum and elytra markedly longer, oriented more or less mesad. Body length 8.5–13.0 mm, width 3.8–5.0 mm.

Head across eyes ×0.96–0.98 width of anterior pronotal margin, outer margins of frons slightly dilated over antennal insertions and then slightly concave, converging anteriorly. Anterior margin of labrum transversely subtruncate, with 1–3 small rounded protuberances. Frons flat, punctures in the middle nearly equal in size to eyefacets, mostly separated by ca 1.5 diameters, becoming gradually larger and closer (separated by 1 diameter or less) posterolaterad. Temples in dorsal view bluntly obtuse, prominent, in posterolateral view with impunctate and strongly shining concavity opposing anterior corners of pronotum. Length of antennae ×0.94 width of head across eyes. Scape 2.40–2.66 times longer than wide, almost as long as antennomeres II–IV combined. Antennomere III longer than neighbouring ones, 2.28 times longer than wide; IV and V subequal, 1.25 times longer than wide; VI and VII subequal, as long as wide; VIII as long as VII, 1.75–1.87 times wider than long, bell-shaped with prominent acute distal subapical angles. Length of antennal club ×1.52–1.56 its width and ×0.28 length of antenna.

Postmentum concave, shallow punctures somewhat smaller than eye-facets, separated by one diameter or more, interspaces densely microscopically wrinkled, dull. Genae behind eyes with coarse and deep punctures fairly equal in size to eye-facets and separated by 0.5–1 diameters; interspaces microscopically wrinkled, dull.

Pronotum widest before its midlength, PWM/PL = 1.56–1.60, PWP/PWA = 1.18–1.22. Anterior margin bluntly angulate in middle, not bordered. Posterior margin completely bordered, shallowly concave besides posterior angles, those obtuse, not prominent. Basal rim with simple series of dense punctures mostly separated by less than one diameter. Sides narrowly explanate-canaliculate, ×0.5 width of antennal flagellum. Punctation analogous to that of frons, with more or less distinct impunctate mediolongitudinal strip.

Tibiae slender, TI1L/TI1W = 4.3, with acute prominent outer apical angle. Protarsus ×0.77 length of tibia, tarsomere V half the total length of tarsus. Tarsomeres I–III dilated, bilobed, ×0.5 width of antennal club.

Elytra widest before their midlength, EL/EW = 1.11–1.13, moderately separately rounded apically. Humeral angles rectangular, fine sutural line distinct in apical third. Punctures generally smaller and closer than on pronotum, mostly separated by ca. 1 diameter.

Prosternum with bordered anterior margin, in front of intercoxal process transversely convex, neither punctate nor reticulate, with several transverse striae, at sides with irregularly dispersed punctures smaller than eye facets, and with several oblique wrinkles. Hypomera with irregularly dispersed indistinct, small and shallow punctures, densely microscopically wrinkled, dull. Prosternal process flat, rounded apically, slightly longitudinally impressed between procoxae; punctures markedly smaller than eye-facets, irregularly dispersed and separated by several diameters, interspaces smooth and shining.

Metasternum in the middle flat, impressed mediolongitudinal furrow behind its midlength not reaching posterior intercoxal margin of metasternum. Punctures equal in size to those of prosternal process, separated by more than one diameter, becoming markedly coarser and closer laterally; interspaces smooth and shining. Anterior intercoxal process depressed, impunctate. Caudal marginal lines of mesocoxal cavities arcuately interconnected in the middle, closely bordering mesocoxal cavities all along their length, their outermost recurrent portion very short, indistinct. Punctation of abdominal sterna analogous to that of metasternum. Caudalmarginal lines of metacoxal cavities closely bordering coxal cavities.

Male genitalia. Median lobe of aedeagus without distinct anterolateral subapical angles, dorsal valve of phallotreme not reaching apex of aedeagus, completely regularly sclerotized/pigmented ( Fig. 5 ). Lateral margins of tegmen in basal half subparallel, in distal half moderately converging distad, apex broadly and flatly rounded ( Fig. 9 ).

Differential diagnosis. Glischrochilus forcipatus differs from the other species of G. japonius complex in its more slender body and legs, as well as in the peculiar form of male mandibles, which are rather narrow and straight in basal half and abruptly curved inwards at their midlength. Male genitalia resemble those of G. parvipustulatus and are markedly different from those of G. japonius . All species of the G. japonius complex can be distinguished according to the following key.

Distribution. So far known only from three mountainous localities in Sichuan province, China.

Figures

FIGURES 1 – 4. Habitus of Glischrochilus. 1 — G. forcipatus (Sichuan); 2 — G. japonius (Hubei); 3 — G. jelineki (paratype); 4 — G. parvipustulatus (Hubei). Scale bar 5 mm.

FIGURES 5 – 12. Male genitalia of Glischrochilus. 5 – 8 median lobe of aedeagus; 9 – 12 tegmen. 5, 9 — G. forcipatus; 6, 10 — G. japonius; 7, 11 — G. jelineki; 8, 12 — G. parvipustulatus. Scale bar 0.5 mm.