Desmopachria tenua, 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 tenua sp. nov.

Figures 9-12 , 76

Type locality.

Guyana, Region IX, Parabara, trail to mines, 2°05.095'N 59°14.174"W.

Diagnosis.

This species has a distinctive dorsal maculate color pattern (Fig. 9 ). Also, the male median lobe in lateral aspect is extremely slender (Fig. 10 ). The lateral lobes are moderately broad and twisted with the apical portion leaf-like (Figs 11 , 12 ). The species does not fit into any of the recognized groups of Desmopachria , and it is not especially similar to any others in the “ungrouped” species.

Description.

Measurements. TL = 1.5 mm, GW = 1.0 mm, PW = 0.7 mm, HW = 0.5 mm, EW = 0.2 mm, TL/GW = 1.6, HW/EW = 2.1. Body oval, laterally broadly curved, lateral margins slightly discontinuous between pronotum and elytron, body broadest across elytra at ~ midlength of body (Fig. 9 ).

Coloration (Fig. 9 ). Dorsal surface of head and pronotum pale orange; elytron orange-brown with pale orange maculae at humeral angle, anterobasally, subbasally near humeral angle, medially, along mediolateral margin, subapically along margin and at apex. Head appendages, pro- and mesothoracic legs and ventral surfaces of prothorax pale orange, maculae relatively well defined and variously confluent (Fig. 9 ); other ventral surfaces orange-brown.

Sculpture and structure. Head broad, anteriorly produced, rounded; anterior margin of clypeus curved, flattened, margined with conspicuous, continuous narrow bead; surface of head shiny, very finely and sparsely punctate; eyes large (HW/EW = 2.1); antennae short, scape and pedicel relatively large and rounded, flagellomere III long and slender, apically expanded, antennomeres IV-X short and broad, lobed at anterodorsal angle, antennomere XI elongate, apically pointed. Pronotum short, lateral margins short, slightly curved with continuous narrow bead, slightly wider medially; surface shiny, finely, indistinctly punctate. Elytron moderately broad, laterally broadly curved; surface shiny, finely punctate throughout. Prosternum extremely short, longitudinally compressed, medially slightly carinate; prosternal process slender anteriorly, with distinctive, small medial tubercle, apically short and moderately broad, medially concave, apically pointed. Metaventrite broad and evenly smoothly convex medially, surface shiny, very finely punctate; metaventrite wings extremely slender. Metacoxa with medial portion short, <1/3 length of metaventrite medially, metacoxal lines slightly divergent anteriorly; lateral portion of metacoxa extremely large, anteriorly strongly expanded; surface shiny, extremely finely punctate. Metatrochanter large, subequal to length of ventral margin of metafemur; legs otherwise not noticeably modified. Abdomen with surfaces shiny and smooth, very finely and sparsely punctate.

Male genitalia. Male median lobe in lateral aspect long, extremely slender, and slightly curved, slightly expanded subapically on dorsal surface, apex narrowly pointed (Fig. 10 ); in ventral aspect slender, lateral margins evenly, broadly curved to pointed apex (Fig. 11 ). Lateral lobe in lateral aspect broad, apically twisted, apex leaflike and curved dorsad, apex pointed (Figs 11 , 12 ).

Sexual dimorphism and variation. Two specimens were examined, a male and one other. They are not noticeably different. It is not clear if the second specimen is a male or female.

Etymology.

This species is named Desmopachria tenua , Latin for slender, for the very thin male median lobe in lateral aspect.

Distribution.

This species is only known from the type locality in Guyana (Fig. 76 ).

Type material.

Holotype in CSBD, male labeled, "GUYANA: Region IX 2°05.095'N, 59°14.174'W, 250m Parabara, Trail to mines detrital pools in forest leg. Short, Isaacs, Salisbury 2.xi.2013; GY13-1102-01A/ SEMC1271250 KUNHM-ENT [barcode label]/ HOLOTYPE Desmopachria tenua Miller, 2021 [red label with black line border]." Paratypes, 1 in SEMC labeled same as holotype except “… / SEMC1271268 KINHM-ENT [barcode label] …” and “/… PARATYPE Desmopachria tenua Miller, 2021 [blue label with black line border."

Checklist of ungrouped Desmopachria species

Desmopachria amrishi Makhan, 2012 - Suriname

Desmopachria andreae Megna & Sánchez-Fernández, 2014 - Cuba

Desmopachria attenuata Régimbart, 1895 - Brazil (Braga and Ferreira-Jr. 2014)

Desmopachria balfourbrownei Young, 1990 - Brazil (Braga and Ferreira-Jr. 2014)

Desmopachria barackobamai Makhan, 2015 - French Guiana. Although described as being near Desmopachria geijskesi , this species appears more likely to be in the Desmopachria ubangoides species-group given the shape of the genitalia and the seemingly prominent male anterior clypeal margin in the illustrations provided ( Makhan 2015: fig. 2). The description is inadequate to make a more definitive assessment, so the species is left ungrouped in Desmopachria ( Miller 2001).

Desmopachria divergens sp. nov. - Venezuela

Desmopachria geijskesi Young, 1990 - Suriname

Desmopachria hylobates Young, 1993 - Brazil

Desmopachria nigrocapitata Braga and Ferreira-Jr., 2010 - Brazil

Desmopachria lineata sp. nov. - Venezuela

Desmopachria paradoxa Zimmermann, 1923 - Brazil

Desmopachria rex Gustafson & Miller, 2012 - Venezuela

Desmopachria rishwani Makhan, 2012 - Suriname

Desmopachria soesilae Makhan, 2012 - Suriname

Desmopachria striga Young, 1990 - Peru

Desmopachria subfasciata Young, 1990 - Bolivia

Desmopachria surinamensis sp. nov. - Suriname

Desmopachria tambopatensis Miller, 2005 - Peru

Desmopachria taniae Miller, 1999 - Bolivia

Desmopachria tenua sp. nov. - Guyana

Figures

Figures 1 - 12. Desmopachria species. (1, 2) Desmopachria divergens 1 habitus 2 male genitalia, ventral aspect. (3,4) Desmopachria lineata 1 habitus 2 male genitalia ventral aspect (5 - 8) Desmopachria surinamensis 5 habitus 6 - 8 male genitalia 6 median lobe, right lateral aspect 7 median lobe, ventral aspect 8 right lateral lobe, right lateral aspect (9 - 12) Desmopachria tenua 9 habitus 10 median lobe, right lateral aspect 11 median lobe and right lateral lobe, ventral aspect; 12 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.