Desmopachria lineata, 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 lineata sp. nov.

Figures 3 , 4 , 76

Type locality.

Venezuela, Amazonas State, near Iboruwa, “Tobogancito,” 5°48.414'N, 67°26.313'W.

Diagnosis.

This species is distinct in having coarse punctation on the pronotum and elytron with many punctures on the elytron arranged in distinctive longitudinal linear series, often confluent such that linear grooves are formed (Fig. 3 ). The male genitalia are distinctive with the median lobe shorter than half the length of the lateral lobes, broad and apically truncate and the lateral lobes elongate, apically somewhat expanded and with a dense series of elongate setae on the apicomedial surface (Fig. 4 ). Specimens are rather large for Desmopachria (TL = 2.6-2.8 mm). This species is similar to members of the Desmopachria portmanni group, especially Desmopachria grammosticta Braga & Ferreira-Jr., which also has linear series of elytral punctures. However, Desmopachria lineata does not have the characteristic sexually dimorphic prosternal process of the Desmopachria portmanni species-group (including Desmopachria grammosticta ). The prosternal process in males of Desmopachria lineata is not bifurcate with a medial pit, instead it is similar to the process in females. This is an unusual species in that it appears phonetically similar to members of the Desmopachria portmanni group, but it lacks the bifid male prosternal process. It is certainly possible that the character states and relationships among these taxa is more complicated than currently understood. It seems clear that investigation of the utility and diversity of these and other characters among this group of Desmopachria should be investigated in the future.

Description.

Measurements. TL = 2.6-2.8 mm, GW = 1.9-2.0 mm, PW = 1.4-1.5 mm, HW = 1.0 mm, EW = 0.5-0.6 mm, TL/GW = 1.4, HW/EW = 1.8. Body large for genus, very broad, rounded, laterally broadly curved, lateral margins slightly continuous between pronotum and elytron, body broadest across elytra anterior at ca. midlength of body (Fig. 3 ).

Coloration. Dorsal surface of head, pronotum and elytron red brown, moderately uniform in color throughout. Head appendages, pro- and mesothoracic legs and ventral surfaces of head and prothorax orange; other ventral surfaces red.

Sculpture and structure. Head broad, anteriorly produced in rounded lobe; anterior margin of clypeus curved, flattened, margined with conspicuous, continuous flattened bead; surface of head shiny, finely but distinctly punctate over entire surface; eyes moderately 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, lobed at anterodorsal angle, antennomere XI elongate, apically pointed. Pronotum very short, lateral margins short, broadly curved, more so anteriorly, with continuous narrow bead; surface shiny, coarsely punctate medially and along most of anterior margin, less punctate lateromedially, punctures irregular, some confluent. Elytron moderately broad, laterally broadly curved; surface shiny, more coarsely punctate than pronotum, punctation distinctive and prominent, irregular, many punctures confluent forming distinctive longitudinal lines and grooves. Prosternum extremely short, longitudinally compressed, medially slightly carinate; prosternal process slender anteriorly, with distinctive, low medial tubercle, apical portion broad basally with broad basal U-shaped region and concave slender apical process emerging from between branches of U, apically narrowly rounded. Metaventrite broad and evenly convex medially, surface shiny, coarsely punctate, punctures forming longitudinal, linear series; 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, evenly and coarsely punctate. Metatrochanter large, subequal to length of ventral margin of metafemur; legs otherwise not noticeably modified. Abdomen with surfaces shiny and smooth, most of surface coarsely punctate.

Male genitalia. Male median lobe in dorsal aspect short and broad, <1/2 length of lateral lobe, apex slightly broadened, apically truncate with rounded lateral margins, medially very finely emarginate, (Fig. 4 ). Lateral lobe in dorsal aspect slender, elongate, evenly expanded apically and broadly curved mediad, apicomedial surface with dense, long setae (Fig. 4 ).

Sexual dimorphism. No obvious sexual dimorphic features were discovered.

Variation. There is some degree of variation in the punctation on the pronotum, elytron and ventral surfaces from specimen to specimen with some with punctures coarser, more confluent, with more strongly marked linear series. But in all cases, some degree of coarse linear series is present on the elytra and punctation is coarse overall compared with most other species in the genus.

Etymology.

This species is named Desmopachria lineata , Latin for lined, for the distinctive linear series of punctures on the disc of the elytron (Fig. 3 ).

Distribution.

This species is known from Amazonas and Bolivar States, Venezuela, and (Fig. 76 ).

Type material.

Holotype in MIZA, male labeled, "VENEZUELA: Amazonas State 5°48.414'N, 67°26.313'W, 80m nr. Iboruwa: “Tobogancito” 13.ii.2009; leg. K.B. Miller VZ09-0113-02E; leaf-choked detrital pools in forest/ SEMC0858759 KUNHM-ENT/ HOLOTYPE Desmopachria lineata Miller, 2021 [red label with black line border]." Paratypes, 2 in SEMC labeled, "VENEZUELA: Bolivar State 4°28.782'N, 61°34.904'W, 853m 1 km E. Pauji, trib. Of Rio Pauji 16.vii.2010;leg Short, Tellez, Arias along stream; VZ10-0716-01A/ …” with barcode labels SEMC0906695 and SEMC0906722.

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.