Hydaticus (Prodaticus) panguana, Megna & Balke & Apenborn & Hendrich, 2019

Megna, Yoandri S., Balke, Michael, Apenborn, Rico & Hendrich, Lars, 2019, A review of Peruvian diving beetles of the genus Hydaticus Leach, 1817, with description of Hydaticus (Prodaticus) panguana sp. nov. and notes on other Neotropical species (Coleoptera: Dytiscidae), Zootaxa 4615 (1), pp. 113-130 : 114-116

Hydaticus (Prodaticus) panguana sp. nov.

( Figs 2A , 4 , 8, 9A )

Type locality. Peru, Huánuco Department, Panguana, River Yuyapichis ; at 9.62S 74.93W, ca. 230 m above sea level (a.s.l).

Holotype, male ( MUSM). “ PERU, Yuyapichis river, Panguana, Huánuco Department , Peru , 10.v-25.vii.2013, - 9.6167S, - 74.9333W, ca. 230 m, leg. R. Apenborn ”, / “ Holotype Hydaticus panguana sp. nov., Y. S. Megna, L. Hendrich & M. Balke det. 2018” [red printed label] . Paratypes: 4 specimens with the same label data ( MUSM, ZSM) ; 1 ex., “ Peru Prov. Huánuco R. Yuyapichis, Stat. Panguana, 9°37ʹS, 74°35ʹW, Wald Station 27.9.- 10.10.2017 leg. Burmeister ” ( ZSM). Each paratype is provided with a red printed paratype label .

Description of holotype. TL = 14.0 mm; TL-H = 13.3 mm; MW = 7.2 mm. Body oval, elongate, slightly attenuated posteriorly, dorsoventrally depressed; subparallel medially, widest just behind middle, lateral outline continuous in dorsal aspect.

Colour. Dorsal surface predominantly black. Head capsule black with clypeus and frons testaceous ( Fig. 2A ). Pronotum black with lateral margins testaceous. Elytron black, with two lateral testaceous spots, one basal and another just behind middle, lateral margin of apex largely irrorated. Ventral surface predominantly rufous, antenna, prosternum, mouthparts, pro-, meso- and metathoracic legs testaceous.

Sculpture and punctation. Dosal sculpture consisting of very fine, dense micropunctures and fine microreticulation. Protarsomeres II with strong reticulations on the dorsal surface.

Structure. Pronotum with posterolateral angle produced and acute, posterior margin broadly sinuate and recurved lateral to basomedial lobe. Prosternal process almost flat. Metaventral wing relatively broad basally, narrow laterally with anterolateral margin straight. Protarsomere I with a series of spines across the dorsal surface. Protibia with stout pegs on the apicodorsal surface. Mesotarsomeres with a small basal brush of setae ventrally. Metatibial spurs acuminate apically. Posterior surface of metafemur with few large punctures on anterior surface and without interspersed small punctures. Metatibia without punctures on anterior surface; posterior surface with dorsal series of seven bifid setae curved ventro-basally, not parallel to dorsal margin. Metatarsal claws unequal, anterior claw shorter than posterior one.

Male genitalia. Median lobe of aedeagus narrow in ventral view; in lateral view enlarged in apical third and with apex rounded ( Fig. 4 ). Parameres are not illustrated because by no means useful in identification of most species of Hydaticus .

Sexual dimorphism. Male with protarsomeres I-III enlarged to form a large oval palette which ventrally bears 22 rounded suckers; mesotarsomeres I-III moderately enlarged, ventrally with 14 rounded suckers. Female with TL = 13.0– 13.2 mm; TL-H = 12.3–12.5; MW = 6.9–7.1 mm; metatarsomeres of female with natatory setae on posteroventral margin.

Diagnosis. TL = 13.0–14.0 mm; TL-H = 12.3–13.3 mm; MW = 6.9–7.15 mm; pronotum black with lateral margins testaceous; elytron with two lateral testaceous spots, one basal and another just behind middle, lateral margin of apex largely irrorated; protarsomere I with a series of spines across the dorsal surface; metatibia with bifid setae curved ventro-basally on posterior surface; median lobe of aedeagus with apex rounded and curved toward the dorsal margin in lateral view.

Differential diagnosis. The shape of the median lobe of H. panguana sp. nov. is similar to that of H. xanthomelas ( Fig. 7 ) but both species can be easily separated by its different size (TL= 13.0–14.0 mm in H. panguana sp. nov. and TL = 9.6–10.4 mm in H. xanthomelas ) and the colour pattern of the elytra ( Figs 2A, 2D ).

Etymology. This species is named in reference to the “Área de Conservación Privada Panguana”, where the species was discovered. The name is a noun in the nominative singular standing in apposition.

Distribution. So far Hydaticus panguana sp. nov. is only known from the type locality in Huánuco Department, Panguana Field Station, Peru ( Fig. 8). Probably more widespread in the Amazonian lowlands.

Ecology. Most specimens of Hydaticus panguana sp. nov. were collected in a partly shaded, shallow, temporary, ditch-like forest pool, rich in decaying leaves and twigs ( Fig. 9A ). The species is sympatric if not syntopic with H. lateralis and H. subfasciatus .

Figures

FIGURE 2. Dorsal habitus of H. panguana sp. nov. (A), H. lateralis (B), H. subfasciatus (C) and H. xanthomelas (D). All specimens collected in Panguana, Peru. Scale bar = 5 mm.

FIGURE 9. Habitats of H. panguana sp. nov. and H. lateralis (A), and H. subfasciatus and H. lateralis (B) in Panguana, Huànuco, Peru. Shallow and temporary forest pool with rotten leaves and wooden debris (A), and Aguajal forest pond (B).

FIGURES 4–7. Median lobe of aedeagus in dorsal (A) and lateral view (B): H. panguana sp. nov. (4), H. lateralis (5), H. subfasciatus (6), and H. xanthomelas (7). Scale bar = 1 mm.