Hydaticus (Prodaticus) hauthi, Hendrich & Balke, 2020

Hendrich, Lars & Balke, Michael, 2020, Hydaticus (Prodaticus) hauthi sp. nov., a new diving beetle from the cloud forest in the Cordillera El Sira, Peru (Coleoptera: Dytiscidae), Zootaxa 4743 (3), pp. 419-426 : 420-421

Hydaticus (Prodaticus) hauthi sp. nov.

( Figs 1a , 2 , 5, 6 , 7 )

Type locality. Peru, Huanuco Department, Cerros del Sira , 1,550 m, 9°25’34.05”S 74°44’8.38”W .

Holotype,male ( MHN-UNMSM).“ PERU, Huanuco Dep., Cerros del Sira , 1550m, 9°25’34.05”S 74°44’8.38”W, 6.10.2012, local collector”, “ Holotype Hydaticus hauthi sp. nov., Hendrich & Balke det. 2019” [red printed label] ( MHN-UNMSM) . Paratypes (5 specimens): 4 males and one female with the same label data as holotype ( ZSM). Each paratype is provided with a red printed paratype label .

Description of holotype. TL = 14.1 mm; TL-H = 13.5 mm; MW = 7.5 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 slightly testaceous ( Fig. 1a ). Pronotum black with lateral margins testaceous. Elytron black, lateral margin of apex sparsely irrorated. Ventral surface predominantly black, antenna, prosternum, mouthparts and fore legs testaceous, middle and hind legs almost black.

Structure and sculpture. Head with fine dense punctation and scattered stronger punctures; additionally with strong punctures concentrated in two spots in anterior third, and with longitudinal rows of strong punctures along postero-medial margins of eyes. Pronotum with posterolateral angle produced and acute, posterior margin broadly sinuate and recurved lateral to basomedial lobe. Pronotum with fine, dense punctation, and row of strong punctures along anterior margin; scattered strong punctures and traces of wrinkles near lateral margins, and row of stronger punctures near posterior margin on both sides of middle. Elytron with very fine microreticulation and scattered stronger punctures. Two rows of well-developed and deep punctures visible. Ventral surface with fine microreticulation; metacoxae and ventrites with fine scattered punctation and with stronger punctures along margin of last ventrite. Prosternal process almost flat. Metaventral wing relatively broad medially, narrow laterally with anterolateral margin straight. Dorsal surface of protarsomeres I and II with strong and dense reticulations and a series of spines. Protibia with stout pegs on apicodorsal surface. Mesotarsomeres ventrally with a small basal brush of setae. 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; metatibial spurs acuminate apically. 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. 2 ). Parameres are not illustrated because by no means useful in identification of most species of Hydaticus ( Megna et al. 2019) .

Sexual dimorphism. Male with protarsomeres I-III enlarged to form a large oval palette ventrally bearing 22 rounded suckers of different sizes; male protarsomeres I and II with a series of spines across dorsal surface; mesotarsomeres I–III moderately enlarged, ventrally with 14 rounded suckers. Wrinkles on pronotum similar to those in males. Female with TL = 13.6 mm; TL-H = 12.9 mm; MW = 7.4 mm; metatarsomeres of female with natatory setae on posteroventral margin.

Differential diagnosis. The habitus of Hydaticus hauthi sp. nov. is near to that of H. panguana Megna, Balke, Apenborn & Hendrich, 2019 ( Fig. 1c ), but both species can be separated by their different size (TL = 13.6–14.6 mm in H. hauthi sp. nov. and TL = 13.0–14.0 mm in H. panguana ), colour patterns of the elytra ( Figs 1a, c ), and length and shape of the median lobes ( Figs 2 , 4). The other larger species in Peru, H. lateralis Laporte, 1835 (TL = 12.9–13.8 mm), has yellow longitudinal stripes and a subtriangular, postmedial and broad spot on each elytron ( Fig. 1b ). Furthermore, the median lobe of H. lateralis is much smaller and has a different shape than the median lobe of H. hauthi sp. nov. ( Fig. 3 ).

Etymology. The new species is dedicated to our young and keen colleague David Hauth (Marburg, Germany), specialist for different xylophagous beetle families. The specific epithet is a substantive in the genitive case.

Distribution. So far Hydaticus hauthi sp. nov. is only known from the type locality in the El Sira Mountains ( Figs 5, 6 ).

Ecology. All specimens of Hydaticus hauthi sp. nov. were collected in a partly shaded, shallow, temporary forest pool, rich in decaying leaves ( Fig. 6 ). No other Dytiscidae were collected, just a few Gyrinidae have been observed.

Figures

FIGURE 1. Dorsal habitus of H. hauthi sp. nov., holotype, male (a); H. lateralis (b) and H. panguana (c), both from Panguana Research Station, Huanuco Department, Peru. Scale bar = 5 mm.

FIGURE 7. Map, type locality of H. hauthi sp. nov..

FIGURES 2–3. Median lobe of aedeagus in dorsal (a) and lateral view (b): H. hauthi sp. nov. (2), H. lateralis (3) and H. panguana (4). The anterior margin of the membranous lateral “wings” of the median lobe in 3b and 4 b have been enhanced digitally for more contrast and better visibility. Scale bar = 1 mm.

FIGURES 5–6. Cloud forest at 1500 m in the Cordillera El Sira, Peru (5) and habitat of Hydaticus hauthi sp. nov. in Peru (6) (Photos by Armin Niessner).