Metriorrhynchus sericeus Waterhouse, 1879

Bocak, Ladislav, 2007, A Revision Of Metriorrhynchus (Coleoptera: Lycidae) From The Greater Sunda Islands And Continental Asia, Raffles Bulletin of Zoology 55 (2), pp. 253-260 : 258-259

Metriorrhynchus sericeus Waterhouse, 1879

(Figs. 3–4)

Metriorrhynchus sericeus Waterhouse, 1879: 52 . Metriorrhynchus testaceicollis Pic , in litt., Pic, 1921: 11.

Material examined. – Male: lectotype (hereby designated) of M. sericeus (BMNH) , “ Java, Bowring 63.47*”; female, specimen designated as M. testaceicollis sp. n., probable holotype ( MHNP), Java orient., Montes Tengger, 4,000 feet (ca. 1,219 m), H. Fruhstorfer, 1890.

Paralectotypes: 3 females ( BMNH), same locality data .

Others: 1 female ( BMNH), Java ; 2 females ( BMNH), Java, Kediri, Fry coll. 1905-100; 2 females ( BMNH), Java, Horsfield , 60-15, Fry coll. 1905-100; 2 females ( LMBC), Jawa (E), Trawas, E slope Gn. Penanggungan, coll. Bolm, 6–9 May.2001 ; 2 females (reared from larvae) ( LMBC), Bali, 12 km NW of Bedugul ( Buyan lake ), 950 m, coll. Bolm, 29 Apr.–2 May.2001 .

Differential diagnosis. – Metriorrhynchus sericeus is the only species of the genus occurring on the islands of Java and Bali. It resembles M. laosensis new species and M. sericans from Continental Asia and these species can be distinguished only by the shape of male genitalia. I have not found any stable characters in the female genitalia and therefore females cannot be identified using internal or external morphology.

Redescription. – For external characters and colouration see above the redescription of M. laosensis new species.

Measurements. – Body length 10.4–18.3 mm, width at humeri 2.3–4.2 mm.

Variability. – Only very limited variability was found in M. sericeus from Java. Several specimens have the apical-fifth of elytra slightly infuscate and one of these was designated as a new species, M. testaceicollis , in Pic’s collection. Such variability is common in Metriorrhynchus species from the Moluccas (e.g. M. doleschali Redtenbacher, 1868 ). Several species of Xylobanus that occur sympatrically with M. sericeus resemble it in body size, shape and colouration.

Distribution. – Indonesia: Java and Bali.

Remarks. – A lectotype and paralectotypes of M. sericeus are designated here. Although M. sericeus is the only Metriorrhynchus species known from Java until now, I have designated a male specimen as the lectotype because females cannot be distinguished from some related Southeast Asian species in the genus.

The specimen designated by M. Pic as a holotype of M. testaceicollis was found in the collection of the MNHN, but a description of such species has not been found in literature and only Pic (1921) mentioned this name without formal description. Therefore, I believe that it is not a valid name under the current code ( ICZN, 1999). I studied this specimen and found that it cannot be distinguished from M. sericeus . It only differs from typical specimens of M. sericeus by having a slightly infuscate posterior fifth of the elytra.

Metriorrhynchus cribripennis Waterhouse, 1879 was reported from Java by Kleine (1933) but this record is probably based on an incorrect identification of M. sericeus . Unfortunately, no specimens from Java identified by Kleine as M. cribripennenis has been found in any of the probable collections. Metriorrhynchus cribripennis was described from Ternate and according to the morphology of genitalia it is a very distant species.