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 : 38-39

Hydraena (Hydraenopsis) sp. 2

(Figs. 14, 28a)

Material examined. 1 Ψ ( NMW): “ PHIL.: Palawan, P. Princesa Panaguman R. 10°15.150'N 118°58.051' E 17.5.2001, leg. Freitag (d17)”.

Diagnosis. Body approximately 1.20 mm long. Entire body gold-brown; frons and anterior part of elytra slightly darker.

Pronotum slightly wider than long, subquadrate, broadest at the middle; densely but inconspicuously punctate, appearing rather glabrous, interstices shiny; foveae absent; lateral margins convex, not conspicuously denticulate; anterior margin concave almost as broad as posterior margin, the latter biconcave; pronotoelytral angle obtuse; lateral portions widely impressed; hypomeron almost horizontal, lanceolate; distinctly broader than profemora, glabrous, mesal portion narrow, hardly perceptible.

Elytra elongately oval, conjointly rounded, with ca. 17 longitudinal, more or less regular, inconspicuous rows of punctures (approximately 10 between suture and shoulder); punctures very small and very shallowly impressed; interstices and intervals flat, glabrous; explanate margins of elytra narrow, not reaching elytral apex, not serrate; inflexed lateral portion distinctly smaller than metafemur, not reaching elytral apex, glabrous.

Mesoventrite with well developed longitudinal ridges; mesoventral intercoxal process short and broader than pseudepipleuron; metaventral disc distinctly impressed; metaventral plaques widely separated posteriorly, anteriorly convergent, very narrow; intercoxal sternite large, narrower than metafemora and approximately as long as broad.

Gonocoxite ( Fig. 28 a) subtriangular; ventral plate concave in lateral view; margin between apical and basal area not defined; subapical tufts each with two strong setae, almost straight; without pubescence; condyles rather small, slightly retracted; dorsal plate surpassing proximal rim of ventral plate, with one large cavity.

Discussion. This species resembles Hydraena palawanemsis , H. pseudopalawanensis , and H. sp. 1 in shape of the gonocoxite, size, punctures, pronotal shape and general habitus, but deviates considerably from all Palawan species in a number of characters: pronotum and elytra shiny, gold-brown; gonocoxite without pubescence, without demarcation between basal and apical area. However, due to the lack of males we refrain from a formal description.

Distribution ( Fig. 31 ). Panaguman River (10°15.150'N / 118°58.051'E) at border between the two districts of Marufinas and New Panggangan, St. Paul Subterranean River National Park, Puerto Princesa City, central Palawan, Philippines.

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.