Hydraena (Hydraenopsis)

Freitag, Hendrik & Jäch, Manfred A., 2007, Revision of the species of Hydraena Kugelann (Coleoptera: Hydraenidae) from Palawan and Busuanga, with descriptions of eleven new species, and redescription of Hydraena (Hydraenopsis) scabra d’Orchymont, 1925, Zootaxa 1431, pp. 1-44 : 39-40

Hydraena (Hydraenopsis) sp. 3

( Figs. 28 b–d)

Material examined. 1 Ψ ( NMW): “ PHIL.: Palawan, P.Princesa; mountain stream 2km SE Laptay/Napsan, semi-prim.forest, 9°43'N 118°28' E 29.3.1995, leg. Freitag (23)M”; 1 Ψ ( NMW): “ Philippines, Palawan central Tarabanan river, ca. 13 km N San Rafael, ca. 30 m 7. XII. 1995, Kodada & Rigová lgt.”.

Diagnosis. Body approximately 1.45 mm long; habitus as in Fig. 14; elytra and clypeus brown; frons dark brown, almost black; legs and maxillary palpi pale brown; pronotum with broad transverse dark brown band (from anterior 0.3 to posterior 0.2), reaching lateral margins; anterior and posterior margins of pronotum distinctly paler (Fig. 14).

Pronotum about 1.1 times as wide as long, broadest at the middle; disc densely punctate, interstices glabrous; lateral portions less regularly punctate; lateral margins anteriorly slightly convergent, posteriorly sinuate; lateral rim posteriorly inconspicuously denticulate; anterior margin bisinuate; posterior margin convex, slightly narrower than posterior margin; pronoto-elytral angle obtuse.

Elytra elongately oval, apically not conjointly rounded, with approximately 16 longitudinal, rather irregular rows of inconspicuous micropunctures; interstices and intervals slightly convex, glabrous to microreticulate; apical rim inconspicuously denticulate; lateral portion narrow, reaching ca. posterior 0.25; inflexed lateral portion short (reaching ca. posterior 0.3).

Gonocoxite ( Fig. 28 b) subcircular, apically slightly acuminate; margin between apical and basal area not defined; not pubescent, except for a few setae near almost contiguous subapical tufts, which are placed on semicircular discoidal elevation; condyles absent; dorsal plate simple, not surpassing proximal rim of ventral plate, without cavity.

Female tergite X similar to Hydraena kodadai , but more densely setose; hyaline apical margin very slightly emarginate, not notched.

Spermatheca as in Figs. 28 c–d.

Discussion. Undoubtedly, this single female represents an unknown species that can be distinguished from the other known Palawan and Busuanga species by its remarkable gonocoxite. Externally, it differs from the two other species with similar body size, Hydraena scabra and H. hosiwergi , in the slender habitus, and several other characters. However, due to lack of males we refrain from a formal description.

Distribution ( Fig. 31 ). This species was collected from two localities in central Palawan: 1) Tarabanan River, ca. 30 m a.s.l., ca. 13 km north of San Rafael, Conception district; 2) forest stream 2 km south-east of Laptay, Napsan district.

Figures

FIGURE 28. Details of Hydraena (females). a) gonocoxite of Hydraena sp. 2; b) gonocoxite of Hydraena sp. 3; c – d) spermatheca of Hydraena sp. 3.

FIGURE 31. Collecting sites and geographical distribution of Hydraena species in Palawan and Busuanga, including enlarged map of St. Paul National Park: Hydraena palawanensis sp. n., H. pseudopalawanensis sp. n., H. spp. ΨΨ cf. palawanensis / pseudopalawanensis, Hydraena sp. 1, H. manguao sp. n., H. hosiwergi sp. n., H. busuanga sp. n., Hydraena sp. 2, Hydraena sp. 3.