Clypeodytes (Clypeodytes) nicolaii Hendrich, Freitag, Balke & Wendlandt sp. nov.

(Figs 1–4)

Type locality. Cabayugan River Plain, shallow pond between limestone rocks SE Manturon, Cabayugan, GPS coordinates 10°09’N 118°53’E, Puerto Princesa City, Palawan, Philippines.

Type material. HOLOTYPE: Male, “ Philippines, Palawan, P. Princesa SE Manturon, Cabayugan River Plain, shallow pond between limestones, dist. prim. forest, 28m a.s.l., 10°09 ‘N 118°53’E, 19.8.2001 H. Freitag (LSP1) M.” [white printed label] (PNM); “HOLOTYPE Clypeodytes nicolaii sp. nov. Hendrich, Freitag, Balke & Wendlandt des. 2025” [red printed label]. PARATYPES: 13 exs. (7 ♂♂, 6 ♀♀ with same data as holotype and a red printed paratype label (PNM, NMW, ZSM); 4 exs. (3 ♂ ♂, 1 ♀) “ Philippines: Palawan, San Vincente, Port Baton, Pamuayan Falls, muddy pool with rotten leaves, 75m, 10°25’01N 119°12’08E 09.iii.1994, leg. local collector” [white printed label] (CWB); 7 exs. (4 ♂♂, 3 ♀♀) with same data but differing date (“ 11.iii.1994 ”) (CWB).

Description of holotype. TL = 1.7 mm; TL-H = 1.5 mm; MW = 1.05 mm. Body short and robust, attenuated posteriad. Body surface with dense coarse punctures.

Colouration. Head and pronotum yellow, elytra more brownish yellow with black patterns as in Figs 1A, 1B. Epipleura, legs, antennae, maxillary palps and labial palps yellowish (Figs 1A–C), and ventral surface more brownish yellow (Fig. 1C).

Head. Anterior margin of clypeus with thick bead (Figs 1A, B). Frons with sparse and very fine setiferous punctures.Eyes large; posterior margin of eyes contacting occipital line.Behind occipital line surface microreticulated (Figs 1A, B).

Prothorax. Pronotum with setiferous punctures similar to those on frons, increasingly coarser posteriad; lateral pronotal bead present; basal striae distinct (Figs 1A, B). Prosternum slightly tectiform; prosternal process lanceolate, with apex broadly rounded (Fig. 1C).

Meso- and metathorax. Elytron with short basal stria and without sutural line, with prominent and longitudinal carina sublaterally; surface of elytron with dense coarse punctures. Epipleuron in anterior third broad, increasingly narrower posteriad; humeral portion of epipleuron with oblique carina delimiting genicular fossa (Fig. 1D). Anepisternum, metaventrite and metacoxa with sparse setiferous punctures; metaventrite with scattered fine punctures on each side of discrimen (Fig. 1C). Metacoxal lines present. Lobes of metacoxal processes not prominent, with posterior margin straight (Fig. 1C).

Abdomen. Abdominal ventrites 2–3 with coarse punctures similar to those on metacoxa. Abdominal ventrites 4–6 with finer punctation. Punctation almost missing on last visible abdominal ventrite (Fig. 1 C).

Male genitalia. Median lobe of aedeagus in ventral view as in Fig. 2A and in lateral view as in Fig. 2B; in ventral view apical portion straight and slender, with rounded tip. Parameres with two segments and with hookshaped apex (Figs 2C, 2D).

Females. Females are indistinguishable from males externally.

Variation. Paratypes: TL = 1.7–1.75 mm; TL-H = 1.4–1.55 mm; MW = 1.0– 1.05 mm. Some paratypes are generally more lightened than others, so the dark markings on the elytra are not as prominent. Presumably, these specimens were lightened due to prolonged storage in high-proof alcohol.

Etymology. The species is dedicated to Nicolai Wendlandt (Berlin, Germany), father of the last author. Together they began studying aquatic beetles, undertaking countless memorable field trips. His continuous support has been crucial for the last author’s progress in coleopterology. The name is a substantive in the genitive case.

Distribution. Only known from two localities on Palawan Island (Fig. 3). Probably endemic to the island.

Diagnosis. The only other species of Clypeodytes s.str. known from the Oriental region, Clypeodytes bufo (Sharp, 1890), is rather different in the habitus (see Mai et al. 2022). The new species can be easily distinguished from all other species of the genus by the shape of the median lobe with a rounded tip without a pointed and elongated extension, the elytral colour pattern, and the completely yellowish head.

Habitat. As many species of the genus in Asia and Australia, C. nicolaii sp. nov. inhabits stagnant water bodies associated with lotic habitats. At the type locality, all specimens were collected in shallow water, in small puddles along limestone rocks (Fig. 4) in the Cabayugan River flood plain. Here, C. nicolaii sp. nov. co-occurs with an unidentified species of Leiodytes and Hydaticus confusus Boheman, 1858 (both Dytiscidae). A remarkably high abundance of Hydraena (Hydraenopsis) palawanensis Freitag & Jäch, 2007 (Hydraenidae) was also reported from the same puddle (Freitag & Hornyák, 2021). At the other locality the species are labelled as being retrieved from small residual pools with decaying leaves and muddy ground. Based on the coordinates and label, the site is also in a riverbed. Hydaticus confusus, H. philippensis Wehncke, 1876, H. zetteli Wewalka, 2016, Hydrovatus sp. and Lacconectus laccophiloides laccophiloides Zimmermann, 1928 (all Dytiscidae), and Coelostoma sp. (Hydrophilidae) are available with the same collection label and probably occur syntopically with the new species.