Cryptopleurum minutum ( Fabricius, 1775 )

Jia, Fenglong & Zhang, Ruijuan, 2017, A review of the genus Cryptopleurum from China (Coleoptera: Hydrophilidae), Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 57 (2), pp. 577-592 : 578-581

Cryptopleurum minutum ( Fabricius, 1775)

( Figs 1‒8 )

Sphaeridium minutum Fabricius, 1775: 68 . Cryptopleurum minutum: HANSEN (1999: 309) : catalogue, complete synonymy.

Type locality. Anglia [= Great Britain: England].

Material examined. CHINA: QINGHAI: 64 spec. ( SYSU):China, Qinghai, Huzhu County, Beishan Shiepan , 37º02′13ʺN, 102º15′26.27ʺE, 2912 m, 3.iv.2013, F.L. Jia, R.B.Angus & Y.Zhang lgt. (with English and Chinese labels). NEI MON- GOL: 1 male, 1 unsexed spec ( SYSU): Yitulihe, 50º38′24ʺN, 121º35′24ʺE, 13‒15.viii.2008, F.L. Jia lgt. (transcribed from Chinese). GANSU: 7 spec. ( NMPC): China: Gansu province, Lazikou valley, 2120‒2510 m, 34°09.9‒10.1′N 103°48.2‒51.9′E, 28.vi.2005, J. Hájek, D.Král & J.Růžička lgt .; 5 spec. ( NMPC):China: Gansu province, Dagcanglhamo (=Langmusi), 3464‒3644 m, 23‒25.vi.2005, 34°04.6‒05.1′N 102°37.7‒38.1′ E, J. Hájek, D. Král & J. Růžička lgt. Published records. CHINA: NEI MONGOL: without specified locality ( FIKÁČEK et al. 2015a) .

Redescription. Length 1.6–2.3 mm. Dark brown or black with light subhumeral spots, seldom reddish with lateral and basal darkening, or uniformly reddish. Pronotum without microsculpture except on extreme lateral portion ( Fig. 4 ), punctures on head, pronotum and elytra coarse and distinct. Scutellum with punctures. Fifth abdominal ventrite in female without tubercle. Elytra with interval eight low and narrower than neighbouring intervals, but series of punctures distinctly separated ( Fig. 5 ); intervals almost flat basally, becoming convex both apically and laterally ( Figs 1, 3, 5 ) but less distinctly than in C. coomani and C. sulcatum . Metaventrite with coarser and dense punctures. Aedeagus ( Figs 7, 8 ) with parameres ca. 1.2× as long as phallobase; parameres gradually narrowed from base to basal third, then almost parallel to subapex, apex narrowly sharpened; median lobe broad, basal two thirds almost parallel, and then gradually narrowed apicad.

Differential diagnosis. This species is similar to C. subtile , but can be distinguished from the latter by the darker color, and the pronotum, elytra and metaventrite with coarser and more dense punctures. The head and metaventrite are without fine longitudinal microsculpture, and the pronotum only has very fine scale-like microsculpture extremely laterally.

Biology. Living in rotting organic material, such as rotting grass, excrements of mammals, also among various plant debris; in Europe also recorded from bird nests ( RYNDEVICH & LUNDYSHEV 2005).

Distribution. Widespread in Palaearctic Region except north Africa, introduced to the Nearctic ( SMETANA 1978, HANSEN 1999). In China only known from nothern parts (Gansu, Nei Mongol, Qinghai). New record for Gansu and Qinghai.

Figures

Figs 1–8. Cryptopleurum minutum Fabricius, 1775. 1–3 – habitus (1 – dorsal; 2 – ventral; 3 – lateral view). 4 – pronotal punctation. 5 – dorsolateral part of right elytron (A – seventh stria; B – eighth stria). 6 – mesoventral plate and metaventrite; 7–8 – aedeagus (7 – dorsal; 8 – ventral view).