Hydaticus kadumane Wewalka & Hájek, 2025, sp. nov.
Creators: name: Wewalka, Günther
name: Hájek, Jiří
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Dytiscidae
Hydaticus
Hydaticus kadumane

description: Hydaticus kadumane sp. nov.
(Figs 1–2)
Type locality. India, Karnataka State, Kadumane Village, 12°54.9’N, 75°40.5’E.
Type material. Holotype ♂ (NMPC), labelled: “ INDIA: KARNATAKA KADUMANE 12.9152300, 75.6750200 top of a grassy hill; at light, Local coll., 22.XI.2003 ” [printed white label] \ “HOLOTYPUS Hydaticus kadumane sp.n. Wewalka & Hájek 2025” [printed red label].
Description. Habitus. Regularly oval, broadest almost in middle, dorsally little convex; shiny.
Colouration. Head predominantly reddish-brown, dark brown along eyes and on vertex, with two curved dark brown lines between eyes; clypeus brown medially and with two black, oblique, narrow lines near insertion of antennae. Pronotum predominantly yellowish-brown to reddish-brown, narrowly dark brown to black along posterior margin and with a dark brow triangular spot in middle. Elytron dark brown to black with yellowish-brown to reddish-brown pattern: a narrow band on lateral margin almost reaching apex; a curved humeral spot fused with a transverse spot near base; one small fragmented sublateral spot behind middle; a triangular preapical lateral spot with few irrorations. Ventral side predominantly dark brown to black; labium, gula, lateral sides of pronotum, prosternum and epipleura reddish-brown to yellowish-brown. Antennae and palps yellowish-brown. Anterior and middle legs reddish-brown; posterior legs dark brown, femur reddish-brown laterally (Fig. 1).
Structures. Clypeus truncate, clypeal margin and lateral margins of pronotum without beads. Prosternum sinuate anteriorly, obtusely keeled medially. Prosternal process short, in cross-section almost flat, beaded laterally, apex rounded. Metacoxal lines short, divergent anteriorly.
Sculpture. Head with fine, dense punctation and less dense, coarse punctures; additional coarse punctures present along eyes and in two dimples on fronto-clypeal suture; without microreticulation. Pronotum with fine, dense punctation and scattered coarse punctures; with coarse punctures along anterior and near lateral margins and less distinct near posterior margin (except in middle); surface of pronotum (except in middle and at lateral sides) with very fine longitudinal wrinkles; without microreticulation. Elytron with very fine, dense punctation and scattered coarser punctures; with three longitudinal rows of coarse punctures on disc, punctures of sutural row quite regularly and densely distributed, those of discal row more irregularly distributed, and lateral row only indicated by few groups of coarse punctures; additionally with a band of coarse punctures along lateral margin; surface of elytra with very fine dense microreticulation. Prosternal process finely punctured. Lateral parts of metaventrite and metacoxal plates with coarser punctures and shallow wrinkles; metacoxae and abdominal ventrites with fine punctation. Abdominal ventrites laterally with distinct longitudinal wrinkles and traces of fine microreticulation.
Male. Protarsomeres and mesotarsomeres I–III dilated and ventrally provided with suckers; protarsomere I with a dense fringe of setae along basal margin. Median lobe of aedeagus in lateral view bisinuate, lateral lobes arising shortly behind rounded apex (Fig. 2a); in ventral view, apex slightly pointed, lateral lobes broadest close to apex (Fig. 2b).
Female. Unknown.
Measurements. TL: 10.1 mm; TL-h: 9.4 mm; MW: 5.7 mm.
Differential diagnosis. In body size and elytral pattern, Hydaticus kadumane sp. nov. most resembles H. balkei Wewalka, 2015 from Indonesia (West Kalimantan) but it can be separated from that species by more regularly oval habitus, pronotum without microreticulation and shape of the median lobe of aedeagus. In colouration, the new species is also similar to H. macularis Régimbart, 1899 from the Philippines and Malaysia (Sabah) and to H. laetabilis Régimbart, 1899 from both Indonesian and Malayan parts of Borneo Island; it can be distinguished from them by its smaller size and different shape of male genitalia. From other species of the H. sexguttatus group, the new species can be separated by the elytral pattern and the unique shape of the median lobe of aedeagus, which is bisinuate in lateral view.
Etymology. The new species is named after its type locality—Kadumane village, as a gratitude to the people of the village for supporting entomological research. The specific epithet is a noun in the nominative singular, standing in apposition.
Distribution. The species is so far only known from the type locality in south-western Karnataka, India.
description: Published as part of Wewalka, Günther & Hájek, Jiří, 2025, A new species of the Hydaticus sexguttatus species group from India (Coleoptera: Dytiscidae), pp. 595-598 in Zootaxa 5604 (4) on pages 596-597, DOI: 10.11646/zootaxa.5604.4.11, http://zenodo.org/record/15213949