Desmopachria pseudocavia, 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 pseudocavia sp. nov.

Figures 43-45 , 78

Type locality.

Venezuela, Bolivar State, Rio Caripito, near Rio Orinoco, 6.58694°N 67.02912°W.

Diagnosis.

This species belongs to the Desmopachria convexa-signata subgroup based on the small articulable, subapical process on the lateral lobe (Fig. 45 ). Specimens are similar to those of Desmopachria cavia Braga & Ferreira Jr. in size, shape, general features, and the presence of a setose depression medially on abdominal sternite VI. However, Desmopachria pseudocavia has a distinctly different dorsal color pattern (Fig. 43 ; Braga and Ferreira-Jr. 2010: fig. 3A) and similar, but differently shaped male genitalia. In Desmopachria pseudocavia the male median lobe terminates in two short rami which are apically rounded and evenly and strongly curved mediad (Fig. 45 ). In Desmopachria cavia these rami are more linear and are apically more distinctly pointed (Braga and Ferreira-Jr. 2010: figs 3D, E). Also, although both species are extremely small diving beetles, Desmopachria pseudocavia (TL = 1.1-1.2 mm) are even smaller than Desmopachria cavia (TL = 1.3-1.5 mm, Braga and Ferreira-Jr. 2010).

Description.

Measurements. TL = 1.1-1.2 mm, GW = 0.8 mm, PW = 0.6 mm, HW = 0.4-0.5 mm, EW = 0.2 mm, TL/GW = 1.4-1.5, HW/EW = 2.3-2.4. Body broad, ovoid, laterally broadly curved, lateral margins continuous between pronotum and elytron, body broadest across elytra at midlength of body (Fig. 43 ).

Coloration. Dorsal surface of head and pronotum yellow. Elytron brown with diffuse, complex maculae, margins of maculae indistinct (Fig. 43 ). Head appendages, legs, and ventral surfaces yellow.

Sculpture and structure. Head broad, anteriorly rounded, anterior margin of clypeus curved, flattened, margined with conspicuous, continuous flattened narrow bead; surface of head shiny, very finely and sparsely punctate; eyes very large (Fig. 43 , HW/EW = 2.3-2.4); 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, curved with continuous narrow bead of even width throughout; surface shiny, impunctate to very finely and sparsely punctate. Elytron broad, laterally broadly curved; surface shiny, very finely and sparsely punctate. Prosternum extremely short, longitudinally compressed, medially slightly carinate; prosternal process slender anteriorly, with distinctive, small, sharp medial tubercle, apically short and broad, medially slightly carinate, concave, apically acutely 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 divergent anteriorly; lateral portion of metacoxa extremely large, anteriorly strongly expanded; surface shiny, impunctate. 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; abdominal sternite VI with medial longitudinally oval depression with field of setae around margins (Fig. 44 ).

Male genitalia. Male median lobe in lateral aspect short, slightly curved ventrad; in ventral aspect broad basally, narrowed apically, apex formed as lateral, curved rami with medial rounded emargination (Fig. 45 ). Lateral lobe in ventral aspect robust, subapically concave on lateral margin, apex truncate, with distinct small subapical articulable process (Fig. 45 ).

Sexual dimorphism. No obvious sexually dimorphic features were discovered.

Variation. There is substantial variation in the extent and distinctiveness of the dorsal coloration on the elytra (Fig. 43 ), though the basic pattern seems to be conserved. The humeral and anteromedial maculae and the apical maculae are nearly always present and distinctive. The medial longitudinal macula and lateral maculae are range from nearly absent to vague or indistinct to distinctive.

Etymology.

This species is named Desmopachria pseudocavia , Latin for resembling Desmopachria cavia , for the similarities of this species to Desmopachria cavia Braga & Ferreira Jr.

Distribution.

This species is known from Venezuela from the states of Amazonas, Anzoategui, Apure, Bolivar, and Monagas (Fig. 78 ).

Type material.

Holotype in MIZA, male labeled, "VENEZUELA: Amazonas State 4°58.838'N, 67°44.341'W; 95m Communidad Caño Gato, on Rio Sipapo; 16.i.2009; leg. Short, Miller, Camacho, Joly, and García VZ09-0116-01X: along stream/ SM0842899 KUNHM-ENT [barcode label]/ HOLOTYPE Desmopachria pseudocavia Miller, 2021 [red label with black line border]." Paratypes, 94 specimens, each with paratype label, “… / PARATYPE Desmopachria pseudocavia Miller, 2021 [blue label with black line border]" and different barcode labels (Table 1 ); 69 in in MIZA, MSBA and SEMC labeled same as holotype; 3 in SEMC labeled, "VENEZUELA: Amazonas State 4°58.845'N, 67°44.345'W; 100m Communidad Caño Gato on Rio Sipapo; sandy stream; 7.i.2006 AS-06-016; leg. A.E.Z. Short/ …”; 4 in SEMC labeled, "VENEZUELA: Amazonas State 4°55.849'N, 67°44.645'W, 87m Stream along Río Sipapo 16.i.2009; leg. Short, Garcia, Camacho, Miller, & Joly VZ09-0116-02X: stream habitats/ …”; 3 in SEMC labeled, "VENEZUELA: Anzoategui State 9°05.808'N, 64°19.445'W, 236 m River along highway, N. El Tigre 3.ii.2010; leg. A. Short; vegetated backwaters; VZ10-0203-03B/ …”; 2 in SEMC labeled, "VENEZUELA: Apure State 7°37.298'N, 69°3.679'W, 83m side road ca. 10 km E. Mantecal leg. Short, Garcia, & Camacho 18.i.2009; marshy area and pool by road; VZ09-0118-02X/ …”; 2 in SEMC labeled, "VENEZUELA: Apure State 7°38.660'N, 69°18.004'W, 90m between "La Ye" & Bruzual 19.i.2009; Short, Camacho, & García; VZ09-0118-03X: lagoon/ …”; 3 in SEMC labeled, "VENEZUELA: Bolívar State 6.558694°N; 67.02912°W Río Caripito, nr. Río Orinoco, 12.i.2009; leg. Short & Miller VZ09-0112-02A: river margin/ …” 7 in SEMC labeled, "VENEZUELA: Monagas State 9°36.591'N, 63°8.295'W, 45 m S. of Maturin; vegetated river/ morichal margin;2.ii.2010; leg. Short & Garcia; VZ10-0202-01B/ …”.

Figures

Figure 78. Desmopachria species distributions. Desmopachria bifurcita species group and Desmopachria convexa species group.

Figures 28 - 45. Desmopachria species. (28 - 30) Desmopachria bifurcita 28 habitus 29 male median and lateral lobes, dorsal aspect 30 male lateral lobe, right lateral aspect (31 - 33) Desmopachria lata 31 habitus 32 male genitalia, ventral aspect 33 right lateral lobe, right lateral aspect. (34, 35) Desompachria bifasciata 34 habitus 35 male genitalia, ventral aspect (36 - 38) Desmopachria bolivari 36 male genitalia, dorsal aspect 37 right lateral lobe, right lateral aspect 38 median lobe, right lateral aspect 39 Desmopachria ovalis, male genitalia, dorsal aspect (40 - 42) Desmopachria varians 40 habitus 41 male genitalia, ventral aspect 42 right lateral lobe, right lateral aspect (43 - 45) Desmopachria pseudocavia 43 habitus 44 abdominal sternite VI, ventral aspect 45 male median lobe and right lateral lobe, ventral aspect. Scale bars: 1.0 mm for habitus drawings; 0.25 mm (44).