Desmopachria anauine, Braga, 2018

Braga, Rafael Benzi, 2018, Six new species and new records of the genus Desmopachria Babington (Coleoptera: Dytiscidae: Hyphidrini) from Brazil and redescription of D. varians Wehncke, 1877, Papéis Avulsos de Zoologia 58, pp. 1-15 : 2-4

Desmopachria anauine sp. nov.

( Figures 1 A-L)

Diagnosis: Medium size for genus 1.7 mm; presence of fine transverse suture on apical ventrite ( Fig. 1C ); medi- an lobe of aedeagus in dorsal view with basal half broad and apical half narrower,apex pointed arch ( Fig. 1J ); each lateral lobe apically divided into two rami: a ventral rami with acute apex and a dorsal rami with rounded apex ( Figs. 1I, L ).

Description: Holotype male: total length 1.7 mm; maximum width of body 1.2 mm; elytral length 1.2 mm; maximum width of pronotum 0.9 mm.

Colouration ( Figs. 1 A-C): Head and pronotum testaceous, each elytron dark brown ( Figs. 1 A-B); venter testaceous with exception of light brown metacoxae and abdomen ( Fig. 1C ).

Structure and sculpture: Body rounded with very fine, shallow and scarcely distributed punctuation; clypeus beaded; antennae with rounded scape, pedicel narrow- er and longer than others antennomeres, antennomeres 5-9 slightly expanded in apical half. Pronotum short and wide, with lateral bead and without basal striae; elytral suture margined. Prosternal process broad, apically pointed, shallowly concave. Apical ventrite with a fine transversal suture ( Fig. 1D ).

Male genitalia ( Figs. 1 E-M): Median lobe in dorsal view with basal half broad and apical half narrower, pointed arch apex ( Fig. 1J ); lateral margins straight until the apex; in lateral view basal and middle thirds of dorsal side rounded and apical third straight,ventral margin straight, apex sickle shape ( Fig. 1L ). Lateral lobes with apical half divided into two ramus: dorsal one straight, longer, with rounded apex bearing few long setae on its inner margin; ventral rami, shorter, rounded in dorsal margin and straight on ventral margin and apex pointed ( Fig. 1I ); few setae and a row of short setae occur on dorsal margin; in lateral-outer view lateral lobe with only apex of ventral branch visible, base broadened, toward middle of lateral lobe length, dorsal rami narrowing to a rounded apex on which a visible a diagonal concave line ( Fig. 1M ).

Intraspecific variation: Small variations of elytra and pronotum width: maximum width of body 1.0- 1.3 mm; maximum width of the pronotum 0.8-0.9 mm.

Taxonomic notes: This new species belongs to the Desmopachria nitida group sensu Miller (2001) because of the lateral lobes of aedeagus being deeply bifid with the apex divided into two distinct rami. The parallel-sid- ed median lobe with apex pointed arched in combination with ventral rami branch of the lateral lobe having a rounded external margin and pointed apex is unique to this group. Species with similar genitalia are D. liosomata Young 1986 ,which has the median lobe apex almost truncated and ventral rami of lateral lobe with rounded apex, and D. psarammo Miller 1999 , with abruptly pointed median lobe apex and ventral rami branch with straight external margin. In addition, both species are smaller than D. anauine sp. nov. and D. psarammo has elytral macula, which are absent in the new species. According to Miller & Wolfe (2018) description of D. nitida group, D. anauine is the only species of the group with transverse suture in the last sternite, but it should be emphasized this characteristic was not considered in many ancient descriptions and this suture can be overlooked in some species.

Type material: Holotype male: “ Brasil, Amazonas , Novo Airão , Rio / Negro , Arquipélago de/ Anavilhanas, Lago do Prato,/ [20°44’44”S, 60°44’42”W]/ 13.ii.1982. Nessimian J.L. [paper white label]”,“ INPA [plastic blue label]”,“ HTYPE [plastic red label]” ( INPA) . Paratypes: “ Brasil, Amazonas, Novo Airão/, Rio Negro, Arquipélago de/ Anavilhanas, Lago do Prato,/ [20°44’44”S, 60°44’42”W]/ 13.ii.1982. Nessimian J.L. [paper white label]”, “490 [plastic blue label]” “ PTYPE [plastic red label]” (1 ex.) ( DZRJ). “ Brasil, Amazonas, Novo Airão,Rio/ Anavilhanas,Rio Negro,Lago Xidaua,/ [20°44’44”S, 60°44’42”W],/ 25.i.1982, Nessimian J.L. [paper white label]”,“2673 [plastic blue label]”,“ PTYPE [plastic red label]” (4 exs.) ( DZRJ).

Etymology: The specific name anauine refers to “Rio Anauiné”, a river that by corruption of word became “Anavilhena” or “Anavilhana”, and is part of the second largest fluvial archipelago in the world, as well as the place of origin of the type material of this new species. It is a noun in the nominative singular standing in apposition.

Geographic distribution: Only known from the type locality on Anavilhanas archipelago in Amazonas State of Brazil.

Figures

Figures 1A-L. Desmopachria anauine. (A) Dorsal View. (B) Colour pattern of elytron. (C) Apical ventrite. (D) Dorsal view. (E-L) Male genitalia. (E) Dorsal view. (F)Ventral view.(G) Lateral view. (H) Coverslip dorsal view. (I) Lateral lobe dorsal view.(J) Median lobe dorsal view (apex slight damaged). (K) Median lobe lateral view.(L) Lateral lobe lateral view.Figs.1A-D scale bars= 1 mm,Figs.1E-L scale bars= 0.1mm.