Cryptopleurum ferrugineum 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 : 587

Cryptopleurum ferrugineum Motschulsky, 1863

( Figs 32‒38 )

Cryptopleurum ferrugineum Motschulsky, 1863: 448 . Cryptopleurum ferrugineum: HANSEN (1999: 309) : catalogue, complete synonymy.

Type locality. Continent indien [= India].

Type material. Not examined.

Additional material examined. CHINA: GUANGDONG: 2 males, 3 females ( SYSU): Canton, South China, Honam Island, Panyu District, 22.94ºN 113.38ºE, 9.iii.1948 (hand-written).

Redescription. Length 1.9–2.1 mm. Dark yellow brown with light color apically. Elytra with intervals elevated apically ( Figs 32, 34 ), intervals much broader than striae, with irregular punctures on intervals ( Figs 32, 35 ), the seventh and eighth striae completely separated ( Fig. 35 ), interval eight as wide as neighbor intervals. Metaventrite with a curved fine elevated line enclosing mesocoxal cavity that derived from femoral line near anterolateral angle of metaventrite ( Figs 36 ), middle portion of elevation smooth between coarse punctures but shagreened around edges. Aedeagus ( Figs 37, 38 ): length of parameres and phallobase combined ca. 7× as long as basal width of both parameres. Paramere ca. 1.7× as long as phallobase, apex narrowly rounded and curved inwards subapically, with membrane projecting slightly inwards subapically. Median lobe ca. 7.2× as long as width at midlength, abruptly narrowed at apical fifth, apical portion thin.

Differential diagnosis. This species can be easily distinguished from other known species occurring in the Oriental Region by these two characters combined: elytra with the seventh and eighth striae completely separate, interval eight as wide as the neighboring intervals ( Figs 34, 35 ); and the metaventrite with a curved elevated line enclosing the mesocoxal cavity, being sharply defined mesally, and laterally connected to the femoral lines near the anterolateral angle ( Fig. 36 ).

Biology. Unknown.

Distribution. Widespread Oriental species so far recorded from India, Sri Lanka, Vietnam, Singapore and Sumatra (Indonesia), in the west reaching up to Saudi Arabia. Newly recorded from China (Guangdong).

Remark. Cryptopleurum ferrugineum was recorded with a question mark by dʼORCHYMONT (1913) from Taiwan (Taihorin), which was adopted by KNISCH (1924) and FIKÁČEK et al. (2015a). However, dʼORCHYMONT (1926) stated that this record actually refers to C. subtile , which was correctly reflected by HANSEN (1999). Therefore, previous records of C. ferrugineum from Taiwan are based on misidentification, and the species is not known to occur in Taiwan at the moment.

Figures

Figs 32–38. Cryptopleurum ferrugineum Motschulsky, 1863. 32–34 – habitus (32 – dorsal; 33 – ventral; 34 – lateral view). 35 – lateral part of right elytron (A – seventh stria; B – eighth stria). 36 – meso- and metaventrite. 37–38 – aedeagus (37 – dorsal, 38 – ventral view).