Desmopachria tumida, Miller, 2022

Miller, Kelly B., 2022, Nineteen new species of Desmopachria Babington, 1841 (Coleoptera, Adephaga, Dytiscidae, Hydroporinae, Hyphydrini) with notes on the taxonomy of the genus, ZooKeys 1136, pp. 1-56 : 1

Desmopachria tumida sp. nov.

Figures 23-27 , 77

Type locality.

Venezuela, Bolivar State, Gran Sabana, Pauji, Esmeraldes, 4°28.233'N, 17°35.559'W.

Diagnosis.

This species is characterized by the distinctive lateral longitudinal tumidity on the elytron (Figs 23 , 24 ). The humeral angle in dorsal aspect is subsinuate because of lateral expansion of the tumidity. The male genitalia are distinct with the median lobe broad with the lateral margins medially bisinuate and apically narrowed to an apically rounded apex (Fig. 25 ) and in lateral aspect with the base large and rounded and the apical portion with the dorsal margin linear and with a broad expansion on the ventral margin with the apex slender and apically narrowly rounded (Fig. 26 ). The lateral lobe is broad medially and apically tapered to a pointed apex with a distinct apical socketed “tooth” (Fig. 27 ). This tooth is shared with two other species, Desmopachria apicodente sp. nov. and Desmopachria lateralis sp. nov., together making up the Desmopachria apicodente species-group (see Diagnosis under Desmopachria apicodente for discussion of differences). Desmopachria lateralis also has a prominent lateral longitudinal elytral tumidity, but that species has differently shaped male genitalia (Figs 20-22 ).

Description.

Measurements. TL = 2.0 mm, GW = 1.5 mm, PW = 1.1 mm, HW = 0.7 mm, EW = 0.4 mm, TL/GW = 1.4, HW/EW = 1.8. Body very broad, laterally broadly rounded, lateral margins nearly continuously curved between pronotum and elytron (Fig. 23 ).

Coloration. Head and pronotum evenly orange. Elytron brown, laterally and apically somewhat paler brown-orange. Ventral surfaces and appendages orange to orange-brown.

Sculpture and structure. Head broad, short; anterior margin of clypeus distinctly margined with continuous flattened bead, broader and flatter medially; surface of head shiny, punctation extremely fine and sparse; eyes large (HW/EW = 1.8); antennae short, scape and pedicel relatively large and rounded, flagellomere III long and slender, apically expanded, antennomeres IV-X short and broad, antennomere XI elongate, apically pointed. Pronotum short, lateral margins short, gently curved with continuous narrow marginal bead; surface shiny, punctation very fine, of the same size and evenly distributed except more coarsely punctate posteromedially. Elytron broad, laterally broadly curved, lateral margin distinctly sinuate at humeral angle, with distinct lateral tumidity extending posteriorly from humeral angle (Figs 23 , 24 ); surface shiny, punctation of two sizes, minute and small, evenly punctate. Prosternum extremely short, longitudinally compressed, medially flattened; prosternal process broad, flattened, concave with broad lateral bead, apically pointed. Metaventrite broad and evenly smoothly convex medially, surface shiny, impunctate; metaventrite wings extremely slender. Metacoxa with medial portion short, <1/3 length of metaventrite medially, metacoxal lines slightly sinuate, divergent anteriorly; lateral portion of metacoxa extremely large, anteriorly strongly expanded; surface shiny, extremely minutely punctate. Metatrochanter very large, longer than length of ventral margin of metafemur; legs otherwise not noticeably modified. Abdomen with surfaces shiny and smooth, surface impunctate.

Male genitalia. Male median lobe in in lateral aspect with large, broad, rounded base, apical portion with dorsal margin linear, ventral margin with large expansion medially, apically narrowed and slender to narrowly rounded apex (Fig. 25 ); in ventral aspect broad, long, lateral margins distinctly sinuate medially, apically narrowed to broadly rounded apex (Fig. 26 ). Lateral lobe large, broad medially, narrow basally and apically strongly and evenly narrowed to pointed apex, dorsal margin with long dense series of long setae (Fig. 27 ).

Sexual dimorphism and variation. Only a single male specimen was examined.

Etymology.

This species is named Desmopachria tumida , Latin for swollen, for the laterally tumid, or swollen, elytral margins (Figs 23 , 24 ).

Distribution.

This species is known only from one site in the Gran Sabana of Bolivar State, Venezuela (Fig. 77 ).

Type material.

Holotype in MIZA, male labeled, "VENEZUELA: Bolivar State 4°28.233'N, 61°35.559'W, 867 m Gran Sabana, Pauji: Esmeraldes 16.vii.2010;leg. Short, Tellez, Arias detrital pools by forested stream VZ10-0716-02A/ SEMC0908227 KUNHM-ENT [barcode label]/ HOLOTYPE Desmopachria tumida Miller, 2021 [red label with black line border]." This species is only known from the holotype.

Checklist of Desmopachria apicodente species group

Desmopachria apicodente sp. nov. - Guyana, Venezuela

Desmopachria lateralis sp. nov. - Venezuela

Desmopachria tumida sp. nov. - Venezuela

Figures

Figures 13 - 27. Desmopachria apicodente - group species. (13 - 17) Desmopachria apicodente 13 habitus 14 male median lobe, right lateral aspect 15 male median lobe, ventral aspect 16 male median lobe and lateral lobes, ventral aspect 17 right lateral lobe, right lateral aspect (18 - 22) Desmopachria lateralis 18 habitus 19 left elytron, left lateral aspect 20 male median lobe, right lateral aspect 21 male median lobe and right lateral lobe, ventral aspect 22 right lateral lobe, right lateral aspect (23 - 27) Desmopachria tumida 23 habitus 24 left elytron, left lateral aspect 25 male median lobe, right lateral aspect 26 male median lobe, ventral aspect 27 right lateral lobe, right lateral aspect. Scale bars: 1.0 mm for habitus drawings.

Figures 76, 77. Desmopachria species distributions. 76 ungrouped Desmopachria species 77 Desmopachria apicodente species group.