Desmopachria manco, Miller, 2020

Miller, Kelly B., 2020, Two new species of Desmopachria Babington, 1841 in the D. convexa species group (Coleoptera, Adephaga, Dytiscidae, Hydroporinae, Hyphydrini), ZooKeys 923, pp. 65-77 : 65

Desmopachria manco sp. nov. Figures 1-5 , 58

Type locality.

Guyana, Region IX, Parabara, trail to mines, 2°05.095'N, 59°14.174'W, 250m.

Type material.

Holotype in CSBD (currently in KUNHM, see above), male labeled, "Guyana: Region IX 2°05.095'N, 59°14.174'W, 250 m Parabara, Trail to mines detrital pools in forest leg. Short, Isaacs, Salisbury 2.xi.2013; GY13-1102-01A/ SEMC1271259 KUNHM-ENT/ Holotype Desmopachria manco Miller, 2020 [red label with black line border]." Paratypes, 1 labeled, "Guyana: Region IX 2°52.204'N, 59°55.003'W, 124 m nr. Kusad Mts., marshy area leg. Short, Isaacs, Salisbury 27x.2013; GY13-1027-01A/ SEMC1271270 KUNHM-ENT [barcode label]/ Paratype Desmopachria manco Miller, 2020 [blue label with black line border]."

The paratype specimen was not dissected but it has the same color pattern, size, and other features as the holotype. It is assigned to this species even though it is from some geographic distance away.

Diagnosis.

This is an extremely small species among Dytiscidae and even among Desmopachria (Fig. 1 ; TL = 1.2-1.3 mm). The dorsal diffuse maculae on the elytra are characteristic (Fig. 1 ). The male genitalia include a dispositively diagnostic set of features (Figs 2-5 ) and place the species in the Desmopachria convexa-signata subgroup (see above). The median lobe is short (Figs 2 , 3 ). In lateral aspect it is irregular in shape, medially expanded ventrally and with the apical portion slender, short, slightly curved dorsad and apically narrowly rounded (Fig. 2 ). In ventral aspect it is very broad, basally deeply U-shaped, apically deeply bifid, each ramus broad basally, apically narrowed and slightly curved laterad (Fig. 3 ). The lateral lobe in ventral aspect is elongate, broad, of subequal width throughout to a broadly truncate apex, with the subapical articulable lobe small and broad (Fig. 4 ). The lateral lobe in lateral aspect is very broad basally with the apex slender, subapically slightly expanded on the dorsal margin and apically sharply pointed with the subapical articulable process short and slender (Fig. 5 ).

Description.

Measurements. TL = 1.2-1.3 mm, GW = 0.8 mm, PW = 0.7 mm, HW = 0.4-0.5 mm, EW = 0.2 mm, TL/GW = 1.9, HW/EW = 2.0. Body round, subspherical, lateral margins continuous between pronotum and elytron (Fig. 1 ), dorsoventrally broad.

Coloration (Fig. 1 ). Head and pronotum yellow. Elytron orange, with distinct but weakly margined maculae at humeral angle, anterolaterally extending to near suture, lateromedially and apically; surface not iridescent. Ventral surfaces and appendages yellow.

Sculpture and structure. Head (Fig. 1 ) broad, anteriorly produced in rounded margin; anterior margin of clypeus margined with conspicuous, continuous, flattened bead; surface of head shiny, very finely and sparsely punctate; eyes large (HW/EW = 1.2-1.4); antennae short, scape and pedicel relatively large and rounded, flagellomere III long and slender, apically expanded, antennomeres IV-X short and broad, lobe at anterodorsal angle, antennomere XI elongate, apically pointed. Pronotum short, lateral margins short, broadly curved with narrow, even bead; surface shiny, nearly impunctate medially, more but sparsely punctate along anterior and posterior margins, punctation variable, fine to course. Elytron moderately broad, laterally broadly curved; surface impunctate. Prosternum extremely short, longitudinally compressed, medially slightly carinate; prosternal process slender anteriorly, with distinctive, small medial tubercle, apically short and broad, concave, apically broadly pointed. Metaventrite broad and evenly smoothly convex medially, surface shiny, impunctate, anteromedially with curved transverse carina between posterior margins of mesocoxal cavities; metaventrite wings extremely slender. Metacoxa with medial portion short, about 1/3 length of metaventrite medially, metacoxal lines distinctly divergent anteriorly; lateral portion of metacoxa extremely large, anteriorly strongly expanded; surface shiny, impunctate, but slightly rugulose medially. Metatrochanter large, longer than ventral margin of metafemur anterior to metatrochanter apex; legs otherwise not noticeably modified. Abdomen with surfaces shiny and smooth, impunctate.

Male genitalia. Male median lobe in lateral aspect short, medially somewhat expanded on ventral margin, apically convergent to sharply angulate apex (Fig. 1 ). Median lobe in ventral aspect broad, base in broad “U” shape, apically deeply bifid, each ramus elongate, broad basally, and apically pointed (Fig. 2 ). Lateral lobe in ventral aspect moderately broad, apically gently curved laterad, with apex subtruncate, subapical articulable process oblique and flattened (Fig. 3 ). Lateral lobe in lateral aspect very broad basally, constricted medially, apically slender, slightly and broadly curved dorsad, apex pointed, subapically articulable lobe slender, directed ventrad (Fig. 4 ).

Etymology.

This species is named manco , after Manco, the younger bounty hunter in the Sergio Leone film "For a Few Dollars More".

Distribution.

This species is known from two localities in Guyana, Region IX (Fig. 58 ).

Habitat.

The type and paratype were collected in "detrital pools" and a "marshy area."

Figures

Figures 1 - 10. Desmopachria species. 1 - 5 D. manco 1 habitus 2 - 5 male genitalia 2 male median lobe, right lateral aspect 3 male median lobe, ventral aspect 4 male left lateral lobe, ventral aspect 5 male left lateral lobe, left lateral aspect 6 - 10 D. mortimer 6 habitus 7 - 10 male genitalia 7 male median lobe, right lateral aspect 8 male median lobe, ventral aspect 9 male left lateral lobe, ventral aspect 10 male left lateral lobe, left lateral aspect. Scale bars: 1.0 mm (1, 6).

Figures 58, 59. Desmopachria new species, distribution. 58 D. manco (South America). 59 D. mortimer (Central America).