Cryptopleurum sulcatum Motschulsky, 1863

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 : 583-587

Cryptopleurum sulcatum Motschulsky, 1863

( Figs 24‒31 )

Cryptopleurum sulcatum Motschulsky, 1863: 448 . Cryptopleurum sulcatum: HANSEN (1999: 310) : catalogue.

Type locality. Ceylan [= Sri Lanka].

Material examined. CHINA: HAINAN: 1 male ( SYSU): Hainan Prov. Ledong, Jiaxi Nature Reserve , 18.83ºN 109.18ºE ， 10‒11.ix.2013, Coll. Weicai Xie lgt. (transcribed from Chinese) . YUNNAN: 1 male ( SYSU): Yingjiang County, Nabang , 24.75ºN 97.56ºE, 239 m, 27.v.2016, Yudan Tang & Ruijuan Zhang lgt .; 1 spec. ( NMPC): Tongbiguan vill., at light, 1340 m, 24.60ºN 97.65ºE, 24‒26.vi.2016. Hájek & Růžička lgt .

Redescription. Length 1.8 mm. Dark yellow brown with apical portion of elytra pale; ventral side black with reddish-brown legs. Head and pronotum strongly shagreened between punctures ( Fig. 31 ); a few smaller punctures mixed among coarse punctures on pronotum ( Fig. 31 ). Elytra with intervals strongly elevated and gradually narrowed from base to apex ( Figs 24, 26, 29 ) (stronger and narrower than those of C. coomani ), striae much deeper than other known species from the Oriental and Palaearctic Regions, each interval with a regular row of small punctures ( Fig. 29 ); seventh and eighth striae very close, both situated in the same groove ( Fig. 29 ), interval eight only slightly elevated as a threadlet, punctured striae wider than intervals in posterior quarter. Elevation of metaventrite distinctly shagreened between coarse punctures. Aedeagus ( Figs 27, 28 ): stout, length of parameres and phallobase combined ca. 4× as long as basal width of both parameres. Paramere ca. 2.3× as long as phallobase, ca. 8× as long as wide medially, apex narrowly rounded and curved inwards subapically, with membrane projecting inwards subapically. Median lobe ca. 5.3× as long as width at midlength, distinctly narrowed about apical eighth, apex ca. as wide as paramere at level of paramere.

Differential diagnosis. This species is similar to C. coomani , but can be distinguished from the latter by each elytral interval only having a row of fine setiferous punctures, the punctural striae being distinctly wider than the intervals on the basal half ( Fig. 29 ) and being as wide as or slightly wider than the interval on in the posterior fourth ( Fig. 26 ). The elytral intervals are sharply costate.

Biology. Unknown.

Distribution. The Oriental species known from India, Sri Lanka, Vietnam, peninsular Malaysia and Singapore. First record for China (Yunnan, Hainan).

Figures

Figs 24–31. Cryptopleurum sulcatum Motschulsky, 1863. 24–26 – habitus (24 – dorsal; 25 – ventral; 26 – lateral view). 27–28 – aedeagus (27 – ventral, 28 – dorsal view). 29 – dorsolateral part of right elytron (A – seventh stria, B – eighth stria). 30 – meso- and metaventrite. 31 – pronotal punctation.