Caccothryptus thai, Hernando, Carles & Ribera, Ignacio, 2017

Hernando, Carles & Ribera, Ignacio, 2017, Three new species of the genus Caccothryptus Sharp, 1902 from Asia (Coleoptera: Limnichidae), Zootaxa 4243 (2), pp. 366-370 : 368-370

Caccothryptus thai sp. n. (Figs 3,4)

Caccothryptus compactus group sp2: Hernando & Ribera (2014: 289).

Type locality. Doi Inthanon , Bang Khun Klang, Thailand.

Type material. Holotype male (NMW): "N-THAILAND, 3.-10.10. // 18°32'N 98°32'E // Doi Inthanon, 1200m // Bang Khun Klang, Malicky // & Chantaramongkol 1989"; genitalia extracted and mounted on a transparent card pinned with the specimen; plus red holotype label.

Paratypes. 4 exx ( NMW): 2 exx. same data as holotype, with red paratype labels ; 2 females "NW-THAILAND // Doi Inthanon, 1200m // Bang Khun Klang / 98°32'E 18°32'N"; "1989 // Malicky & // Chantaramongkol"; " Caccothryptus sp.n.? // Hernando & Ribera det 2002"; plus red paratype labels.

Description. Holotype: length 4.9 mm, width 2.6 mm; paratypes: length 4.6-4.8 mm, width 2.5-2.6 mm. Body dark brown (most specimens are teneral, with a lighter colour); oval, elongated, parallel sided. Tarsi and antennae light brown, legs dark brown (as body).

Head: Eye margin strong, with a small denticle by insertion of antennae; with a very narrow supra-ocular sulcus. Eyes slightly prominent. Puncturation on head uniformly fine and very dense; space between punctures similar to their diameter. Two types of pubescence, one erect, castaneous limited to disk; a second golden, very dense, recumbent. Pubescence on frons orientated towards clypeum; pubescence on the lateral and basal areas orientated towards vertex.

Pronotum: Transvere, same width than base of elytra, lateral margins regularly and slightly curved; strongly bordered, borders narrowing towards base. Puncturation similar to that on head, very uniform; spaces between punctures wider than diameter. Pubescence mostly formed by longer erect setae, castaneous; some shorter greyish setae on the lateral margins, absent from disk, which only has erect setae.

Elytra: Disk with coarser puncturation than on pronotum and head; puncturation double, one very fine and dense, a second coarser, very irregular but with 3-4 poorly defined series on disc; some coarse punctures forming irregular 2-3 series on elytral margins. Elytral pubescence double; erect setae castaneous, recumbent setae generally golden, but in some areas darker (colour depends on angle of incidence of light). Recumbent seta with a zig-zag pattern, orientated towards apex. Elytra strongly bordered, border stronger in the humerus and less marked apically, from middle part to apex; almost indistinguishable at apex. Membranous wings well developed.

Venter: Uniformly dark brown. Fully pubescence except hypomeras, which are glabrous; prosternum strongly encased into mesosternum. Prosternum densely punctured, punctures deeper and larger than on dorsum; margins bordered; mesosternum with slightly shallower puncturation than on proternum; disk of metasternum with fine puncturation; lateral process of the metaventrite (metasternal wings) with very coarse puncturation. Glandular pores in 4th abdominal sternite only.

Aedeagus (Figs 3,4): ventral margin of the median lobe with two series of 3-4 irregular, small dents ( Fig. 4 ). Dorsal part of base of parameres in lateral view with a small denticle; apex of parameres and median lobe narrow, fusiform; tips of parameres slightly divergent.

Comparative notes. The species can be clearly separated by the presence of small dents in the median lobe, which is unique among the species of the C. compactus group. The shape of the aedeagus in ventral view ( Fig. 3 B) is also peculiar, with a very compact and fusiform apex, in contrast to all other known species of the group ( Fig. 2 B; Hernando & Ribera 2014).

Etymology. Named in reference to their known distribution. The name is a noun in apposition.

Distribution. So far only known from the type locality.

Remarks. Two females of this species were recorded by Hernando & Ribera (2014) as " Caccothryptus compactus group sp2", but not described due to the absence of males. The finding of males collected together with these females among the unsorted collections of the Naturhistorisches Museum Wien (NMW) allowed us to describe this new taxon here.

Figures

FIGURE 4. Detail of the denticles in the main lobe of the aedeagus of Caccothryptus thai sp. n.

FIGURES 1 – 3. Male genitalia of: 1) Caccothryptus occidentalis sp. n., 2) Caccothryptus schillhammeri sp. n., 3) Caccothryptus thai sp. n. — aedeagus in A) lateral and B) ventral views; C) sternite XIX; D) sternite VIII. Scale bar: 0.5 mm.