Hydraena (Hydraenopsis) jojoorculloi 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 : 12-15

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

(Figs. 4, 16a–h)

Type locality. Manguao Stream (Lake Manguao tributary), Municipality of Taytay, northern Palawan, Philippines.

Type material. Holotype ɗ ( NMW): “ PHIL.: Palawan, Taytay; Lake Manguao tributary, Alipuran Stream, semi-prim. forest c. 40m asl, 10°45'N 119°32' E 29.4.1995, leg. Freitag (15)M”, terminal parts of abdomen and aedeagus glued separately. Paratypes: 2 ΨΨ ( NMW): same locality data as holotype; 1 ɗ ( NMW, aedeagus lacking), 2 ΨΨ ( NMW, mutilated): “ 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”; 2 ΨΨ ( NMW, 1 ex. mutilated): “ PHIL.: Palawan, Taytay; 1/3way high-way to Lake Manguao , Manguao Stream trib., prim.forest c. 35m asl, 10°47'N 119°31' E 29.4.1995, leg. Freitag (13b)M”; 1 Ψ ( NMW): “ PHIL.: Palawan, P.Princesa; S. Vincente Taranaban Riv; 0.5km N of Highway, mountain riv. resid. pool, 10m asl 10°01'N 119°01'E, 30.4.1995 leg. Freitag (16)M”; 1 Ψ ( NMW): “ PHIL.: Palawan, P.Princesa; Junction to Napsan, 8km SW PPC; 20m S Binuan Bridge, sec.veget. c. 20m asl 9°43'N 118°40'E, 28.3.1995 leg. Freitag (22)M”; 1 Ψ ( UPLB): “ PHIL.: Palawan, P. Princesa Panaguman R.PR1, 1.Drift 10°15'09''N 118°58'03''E 17.V.2001, leg. Freitag (47)”; 1 Ψ ( NMW): “ Philippines, Palawan centr. Ulangoan river, 18 km NE San Rafael, 6. XII. 1995, J. Kodada & B. Rigová lgt.”.

Description. Body approximately 1.25 mm long. Habitus as in Fig. 4. Elytra brown; frons dark brown; pronotum, legs and maxillary palpi distinctly paler yellowish brown to gold-brown.

Pronotum wider than long, broadest at anterior 0.3; entire pronotum densely punctate; punctures small and moderately deeply impressed, interstices glabrous; anterior margin slightly concave; anterior angles rounded; lateral rim denticulate; lateral margins anteriorly convergent, posteriorly sinuously convergent; pronoto-elytral angle obtuse; posterior margin slightly biconcave; lateral hypomeron posteriorly slightly broader than profemur, mesal hypomeron narrow, inconspicuous.

Elytra elongately oval, not conjointly rounded apically; each elytron with a tiny excision next to sutural keel, with ca. 16 longitudinal, more or less regular rows of punctures (approximately nine between suture and shoulder); punctures small and moderately deeply (apically shallowly) impressed, interstices and intervals convex to microreticulate; lateral portion moderately explanate, not reaching elytral apex, anteriorly and posteriorly denticulate; inflexed lateral portion (pseudepipleuron) anteriorly slightly broader than metafemur, reaching posterior 0.2, row of punctures inconspicuous; epipleuron narrow, short.

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

Femora with inner margin straight to concave, outer margin conspicuously convex; tibiae with inner margin straight, outer one slightly convex.

Aedeagus ( Figs. 16 a–c) elongate and slender; main piece rather straight in ventral view, slightly sinuous in lateral view; without setae (three micropores present); phallobase asymmetric. Distal lobe intricately shaped, not clearly delimited from main piece; ejaculatory duct distally ending in a tapered stout flagellum, which is dorsally embedded in a less sclerotized ovoid structure. Parameres firmly fused to main piece; left paramere short, moderately wide, inserted at about basal 0.50 of aedeagus, latero-apically with ca. seven moderately long setae; right paramere inserted at about basal 0.55 of aedeagus, longer, wide, apically attenuately rounded, subapically with two parallel rows of ca. four moderately long setae.

Gonocoxite ( Fig. 16 e) subsemicircular, more or less evenly rounded; lateral margin only slightly convex subbasally; setae of subapical tufts straight; basal area of ventral plate with very few small scattered setae; condyles small and inconspicuous; dorsal plate asymmetric, simple, not surpassing outer plate.

Spermatheca as in Figs. 16 f–g; proximal portion distally globular, proximately tubular, bent; distal portion wide and tubular, slightly curved.

Secondary sexual characters. Male profemur with tiny denticle near base of ventral face (dissection of leg recommended). Male terminal sternite elongately subpentagonal, apical margin widely rounded; base slender, very slightly produced laterad; spiculum gastrale almost twice as long as terminal sternite, slightly bent ( Fig. 16 d). Male tergite X apically distinctly excised. Female tergite X ( Fig. 16 h) subsemicircular; lateral margins evenly rounded; disc sparsely covered with setae; subapical fringe of vermiform setae widely interrupted medially, laterally with short trichoid setae; hyaline apical margin notched medially.

Differential diagnosis. This species can easily be distinguished from Hydraena scabra by the smaller size, by the conspicuously yellowish pronotum, and by its smaller and only moderately deeply impressed elytral and pronotal punctures. Furthermore, it can easily be recognized by its aedeagus (main piece rather straight, distal lobe ovoid with flagellum-like structure), the shape of the gonocoxite, and the presence of vermiform setae on female tergite X.

Distribution ( Fig. 30 ). Known only from three localities in northern and central Palawan.

Ecology. This species occurs in small and medium-sized creeks draining hilly lowlands with forest cover. The species was collected manually in shallow, slowly flowing, unshaded reaches with sand, gravel, FPOM and CPOM.

Etymology. Named for Jojo Orcullo (Puerto Princesa City), Palawan artist, for his support during the field work in Palawan and his personal loyalty to the first author.

Figures

FIGURE 16. Hydraena jojoorculloi sp. n. a – c) aedeagus (holotype) in ventral (setae of right paramere omitted), dorsal and lateral view; d) male sternite X and spiculum; e) gonocoxite; f – g) spermatheca; h) female tergite X.

FIGURE 30. Collecting sites and geographical distribution of Hydraena species in Palawan and Busuanga, including enlarged map of St. Paul National Park: Hydraena scabra d’Orchymont, H. jojoorculloi sp. n., H. nielshaggei sp. n., H. zetteli sp. n., H. castanescens sp. n., H. claudia sp. n., H. kodadai sp. n.