Four new species of the genus Caccothryptus (Coleoptera, Limnichidae)

. Four new species of the genus Caccothryptus (Coleoptera: Limnichidae) are described: C . taiwanus from Taiwan; C . orion from Okinawa; C . tibetanus and C . chayuensis from Tibet. All the species belong to the testudo species group ( sensu Hernando & Ribera 2014). Additional specimen data and an updated species list are also given, and C . testudo Champion, 1923 is newly recorded from Thailand.


Introduction
The family Limnichidae, minute marsh-loving beetles, is aquatic and semiaquatic, and represented by about 400 species belonging to 37 genera (Spangler et al. 2001;Hernando & Ribera 2005b).The species diversity of this family is high in the Neotropical and the Oriental Regions (Hernando & Ribera 2005b), but the Oriental fauna of this family has not been well studied.

Diagnosis
Smaller species in the genus; TL = 3.73-4.05mm in male, 3.75-4.20mm in female; parameres weakly pointed in lateral view; apical emargination of parameres deeply U-shaped, with small projections in inner margins.

Etymology
The species is named after the type locality.

Description Male
Body (Fig. 1A) oblong, convex dorsally and ventrally, shiny, densely covered with short and long silver setae.Coloration of body black; legs and antennae paler.
Sternite VIII (Fig. 2D) U-shaped, bearing short setae in apical parts.Sternite IX (Fig. 2E) elongate, with long and stout lateral projections.Aedeagus (Fig. 2A-C) stout, straightly curved ventrally in apical part, punctate in apical part of median lobe and parameres; median lobe wide in lateral view, rather pointed at apex; apical emargination of parameres deeply U-shaped, with small projections in inner margins; apices of parameres rounded in ventral view, weakly pointed in lateral view.

Distribution
Only known from the type locality, Taiwan.

Remarks
This species belongs to the testudo species group (sensu Hernando & Ribera 2014).It resembles C. sinensis Hernando & Ribera, 2014, known from Fujian, China, in the shape of the parameres, which are broadly and deeply emarginated, and differs from it in the following male genital characteristics: apex of the median lobe rather rounded (rather pointed in C. sinensis); median lobe straightly projecting posteriorly (curved postero-ventrally in C. sinensis).

Diagnosis
Smaller species in the genus; TL = 3.68-3.73mm in male, 3.82-4.00mm in female; parameres rather pointed in lateral view, with furrows in ventral part; apical emargination of parameres deeply U-shaped.

Etymology
The species is named after "Orion Beer" (copyright: Orion Breweries, Ltd), which is a local, but wellknown and favored beer in Okinawa.The type locality of this species is situated near the Nago Factory of Orion Beer.
Sternite VIII (Fig. 2I) U-shaped, bearing short setae in apical parts.Sternite IX (Fig. 2J) rather wide, with long and stout lateral projections.Aedeagus (Fig. 2F-H) stout, curved ventrally in apical part, punctate in apical part of median lobe and parameres; median lobe wide in lateral view, pointed at apex; apical emargination of parameres deeply U-shaped; apices of parameres rounded in ventral view; pointed in lateral view.

Distribution
Only known from the type locality, Okinawa-jima, the Ryukyus, Japan.

Remarks
This species belongs to the testudo species group (sensu Hernando & Ribera 2014).It is similar to C. taiwanus sp.nov. in the shape of the male genitalia, but differs from it in the following characteristics: parameres rather pointed in lateral view, with furrows in the ventral part; apex of the median lobe rather pointed in lateral view.

Biological notes
The type locality (Fig. 5A-B) is a small river and the specimens were collected from under the surface of water-logged wood (personal communication from Mr. Masato Mori).

Etymology
The species is named after the type locality.

Description Male
Body oblong, convex strongly in dorsal and slightly in ventral parts, shiny, densely covered with short silver setae.Coloration of body dark brown, but femora and tarsi paler.

Diagnosis
Larger species in the genus; TL = 5.90 mm in male; median lobe minutely serrate in ventral part; apical emargination of parameres V-shaped.

Etymology
The species is named after the type locality.

Male
Body oblong, convex strongly in dorsal and slightly in ventral parts, shiny, densely covered with short silver setae.Coloration of body dark brown, but femora and tarsi paler.
Sternite VIII (Fig. 3H) U-shaped, bearing short setae in apical parts.Sternite IX (Fig. 3I) elongate, with long and slender lateral projections.Aedeagus (Fig. 3E-G) slender, slightly curved ventrally, fi nely punctate in apical part of median lobe and parameres; median lobe wide in lateral view, rather pointed at apex, minutely serrate in ventral part; apical emargination of parameres V-shaped; apices of parameres pointed in ventral view, forming thumb-like projection in lateral view.

Female
Unknown.

Distribution
Only known from the type locality, Tibet.
European Journal of Taxonomy 147:1-17 (2015)RemarksThis species belongs to the testudo species group (sensu Hernando & Ribera 2014).It is related to C. fujianensis Hernando & Ribera, 2014 known from China (Fujian), C. malickyi Hernando & Ribera, 2014 from Vietnam and C. jendeki Hernando & Ribera, 2014 from India, but differs from them in the following characteristics: median lobe with minute serrae in the ventral part, pointed at apex; emargination of parameres rather shallow.