Hydraena (Hydraenopsis) manguao Freitag & Jäch, 2007

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 : 31-32

Hydraena (Hydraenopsis) manguao Freitag & Jäch , sp. n.

(Figs. 11, 25a–h)

Type locality. Manguao Stream (Lake Manguao tributary), 10°46'N 119°31'E, Taytay, northern Palawan, Philippines.

Type material. Holotype ɗ ( NMW): “ PHIL.: Palawan, Taytay; 1/2way high-way to Lake Manguao , Manguao Stream trib., prim.forest c. 30m asl, 10°47'N 119°31'E 03.4.1995,leg. Freitag(13a)M ”, terminal parts of abdomen, aedeagus and several parts of legs glued separately, two legs lacking. Paratypes: 3 ɗɗ (2 exs. NMW, 1 ex. mutilated; 1 ex. UPLB, aedeagus lacking), 3 ΨΨ (2 exs. NMW, mutilated; 1 ex. WPU, mutilated): same locality data as holotype.

Description. Body 1.20–1.30 mm long. Habitus as in Fig. 11. Elytra, pronotal disc and clypeus brown; frons (particularly around eyes) dark brown; pronotal margins, legs, and maxillary palpi distinctly paler.

Pronotum distinctly wider than long, broadest at the middle; entire pronotum moderately densely punctate; punctures small and moderately impressed, interstices glabrous; foveae distinctly impressed; lateral margins convergent anteriorly, slightly sinuously convergent to posterior rectangular angles; lateral rim distinctly denticulate; anterior margins slightly concave, slightly broader than posterior margins; the latter slightly convex; lateral hypomeron distinctly broader than profemur, mesal hypomeron narrow, inconspicuous.

Elytra elongately oval, apex with tiny excision next to sutural keel, with ca. 15 longitudinal, more or less regular, rows of punctures (approximately nine between suture and shoulder); punctures small and moderately deeply impressed; interstices and intervals convex, glabrous; lateral gutter of elytra moderately explanate, not reaching elytral apex; elytral rim posteriorly denticulate; inflexed lateral portion (pseudepipleuron and epipleuron) anteriorly slightly broader than metafemur; pseudepipleuron reaching ca. posterior 0.3; epipleuron distinctly narrower (except at shoulder) and shorter (reaching ca. posterior 0.7) than pseudepipleuron.

Mesoventrite with well developed longitudinal ridges; mesoventral intercoxal process narrower than pseudepipleuron. Metaventral disc moderately impressed; metaventral plaques inconspicuous, pubescent; intercoxal sternite moderately large, as long as broad, slightly narrower than metafemur; metaventrite and ventrites 1–4 moderately pubescent.

Femora slightly curved, inner margin straight to concave. Protibiae slightly curved.

Aedeagus ( Figs. 25 a–c) conspicuously Y-shaped (ventral/dorsal view). Main piece with three setae; apex long, thin, slightly curved to left side; phallobase subsymmetric. Distal lobe intricately shaped, not strongly sclerotized, emerging from lateral projection of main piece. Parameres not articulately connected with main piece, inserted at basal 0.4 of aedeagus; left paramere rather long and slender, slightly curved, apically with one curved and three straight setae; right paramere shorter and broader, apically flat and rounded (dorsal view), curved to left side, with one apical group of (ca. three) rather small setae and another subapical lateral (right) group of ca. five long setae.

Gonocoxite ( Fig. 25 e) subrectangular; apical area of ventral plate very short, setose; subapical tufts short; basal area without pubescence; condyles very weakly developed; dorsal plate simple, not surpassing outer plate.

Spermatheca ( Figs. 25 f–g). Proximal portion crescentic; distal portion discoidal.

Secondary sexual characters. Male profemur with small denticle near base of ventral face. Male terminal sternite subtriangular; apical margin medially convex; lateral margins widely rounded; base moderately broad, distinctly produced into lateral acute appendages; spiculum gastrale rather short (less than two times as long as sternite), almost straight ( Figs. 25 d). Male tergite X distinctly excised apically, rather glabrous. Female ventrite 6 distinctly produced. Female tergite X ( Fig. 25 h) similar to that of Hydraena jojoorculloi , but hyaline apical margin narrow, vermiform setae of subapical fringe very broad and apical notch less deep.

Differential Diagnosis. The external habitus and size of this species are similar to Hydraena palawanensis , H. pseudopalawanensis , H. nielshaggei and H. jojoorculloi . It can be distinguished from H. nielshaggei and H. jojoorculloi by its curved protibia and pronotal colouration (pronotal disc brown), and from H. palawanensis / pseudopalawanensis by its pronotal shape (conspicuously impressed foveae, denticulate lateral rim, which is more convergent anteriorly and posteriorly) and the moderately impressed pronotal and elytral punctures. Primary and secondary sexual characters (aedeagus, spermatheca, female tergite X, gonocoxite, female ventrite 6) illustrate an affiliation to the H. miyatakei lineage (see Jäch & Díaz 1998). Therefore, it can easily be distinguished from the other Palawan species by its typical Y-shaped aedeagus and by the produced female ventrite 6 (abdominal sternite VIII).

Etymology. Named in reference to the geographical distribution, the Manguao (Lake) catchment in the Municipality of Taytay, northern Palawan.

Distribution ( Fig. 31 ). Hydraena manguao is known only from the type locality, Manguao Stream, flowing into Lake Manguao .

Ecology. This species was collected in small creeks draining hilly lowlands with primary forest. It was collected manually in a shallow, very slowly flowing reach with sand, gravel, FPOM and CPOM in an unshaded section.

Figures

FIGURE 25. Hydraena manguao sp. n. a – c) aedeagus (holotype) in ventral, dorsal and lateral view; d) male sternite X and spiculum; e) gonocoxite; f – g) spermatheca; h) female tergite X.

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.