Hemiosus quindiensis González-Rodríguez & Clarkson, 2019

González-Rodríguez, Liza M., García-Hernández, Andrea L. & Clarkson, Bruno, 2019, Two new species of the water scavenger beetle genus Hemiosus Sharp (Coleoptera: Hydrophilidae) from Colombian Andes, Zootaxa 4565 (4), pp. 493-500 : 496-498

Hemiosus quindiensis González-Rodríguez & Clarkson sp. nov.

( Figs. 8‒14 )

Type Material. Holotype (male) (MAUQ-14456) : “ Colombia: Quindío Department, Municipality: La Tebaida,/ Neighborhood : Pizamal / 04°41' 27.6'', 075° 85' 37.7'', 1044 msnm/ 10-10-2014 / Liza María G.R. col./ Lorena G.H y Liza María G.R. det. // Habitat: temporary ponds,/ substrates: muddy/stony, stony/sandy. (Deposited in MAUQ). Paratypes (24): (same data as Holotype: 3 males, 4 females; MAUQ (MAUQ-14457-14458)), (3 males, 3 females; UPTC), (3 males, 3 females; CZUT), (3 males, 3 females; DZUP).

Diagnosis: Total body length 2.8‒3.0 mm in males, 2.8‒3.5 mm in females. Pronotum testaceous with a pair of

black longitudinal markings nearly at medial position. Elytra testaceous with melanic areas. Mesoventral process raised, subrhomboid with raised anterior tooth. Metaventral process narrow. Ventrite 1 with fine acuminate medial carina. Apical notch in ventrite 5 with median portion slightly raised. Aedeagus with each paramere gradually tapering towards apex, rounded at apex; median lobe shorter than parameres, appendices shorter than median lobe, acuminate. Phallobase shorter than parameres in length, strongly asymmetrical in basal half with manubrium distinct.

Description. Size and form (Measurements of the holotype). Total length 3.00 mm; maximum width 1.40 mm; maximum width of head 0.85 mm; maximum width of pronotum 1.00 mm; humeral width 1.30 mm; elytral length 2.15 mm. Body oval, elongate, strongly convex in lateral view ( Fig. 8 ).

Color. Head melanic with strong metallic sheen ( Fig. 8 ). Mouthparts dark brown; maxillary and labial palps testaceous, maxillary palps darkened at apex ( Fig. 8 ); antennae testaceous. Pronotum testaceous, with a pair of black longitudinal markings nearly at medial position, separated by half the width of one spot, without metallic sheen; elytra testaceous with melanic areas ( Fig. 8 ). Ventral face of thorax and abdomen dark-brown to black. Anterior, middle and hind legs testaceous.

Head. Head flattened in lateral view. Ground punctation on frons and clypeus strongly impressed and densely distributed, distance between punctures lesser than width of one puncture; mentum width 0.28 mm, with scattered punctures, shiny and glabrous; maxillary palps nearly as long as maximum width of head; labial palps nearly as long as mentum width.

Thorax. Pronotal margins smooth. Ground punctation on pronotal disc densely distributed, punctures larger than those on head; distance between punctures half width of one puncture. Elytra with serial punctures, moderately impressed; about twice the size of ground punctures on pronotal disc; inner interstriae flat, about 3 times width of a stria; outer interstriae narrow and convex; ground and systematic punctures on inner interstriae about half the size of serial punctures on striae ( Fig. 13 ). Mesoventral process raised, subrhomboid in ventral view, depressed in median portion, posterior portion narrow and long ( Fig. 9 ), projected between mesocoxae, raised anterior portion as a tooth-like projection in lateral view ( Fig. 10 ). Metaventral process narrow, anteriorly with narrow raised carina not projected between mesocoxae, almost reaching the posterior margin of, and as elevated as, mesoventral process; posteriorly with edge of process produced, wide and slightly acuminate; posterolateral margins not produced posteriorly ( Fig. 11 ).

Abdomen. Ventrite 1 with fine acuminate medial carina, slightly broadening posteriorly, anteriorly extended between metacoxae, restricted to anterior portion of the ventrite. Lateral carinae narrow, slightly raised, blunt, about two-thirds the length of the ventrite. Ventrite 2 with fine medial basal carina not reaching posterior margin of the ventrite. Apical notch of ventrite 5 with median portion slightly raised, lateral portions smooth ( Fig. 12 ). Aedeagus with outer margins of parameres subparallel to slightly convex along basal half, gradually tapering distally along apical half, rounded at apex, slightly turned inwards; median lobe shorter than parameres, subcylindrical, rounded at apex; appendices rather shorter than median lobe, acuminate; phallobase elongated, nearly as long as parameres, maximum width at apex, strongly asymmetrical at basal half with manubrium distinct, narrow and truncate at base ( Fig. 14 ).

Variation. Coloration: specimens with lighter-colored and darker melanic areas. Sexual: No obvious sexual dimorphisms other than females being generally larger than males.

Etymology. The species epithet is a reference to the Quindío Department, from where the type specimens were collected.

Natural history. Specimens were collected along riverbanks and in temporary ponds on muddy leaf litter as well as on muddy/stony and stony/sandy substrates ( Fig. 16 ).

Remarks. Hemiosus quindiensis sp. nov. is fairly similar to H. multimaculatus, (Jensen-Haarup) (distributed in Argentina, Chile, and Bolivia) in the coloration pattern (head with strong metallic sheen, maxillary palp darkened at apex, pronotum and elytra with melanic areas), and in some features of the male genitalia (median lobe shorter than parameres; phallobase asymmetrical). The new species differs from H. multimaculatus by the morphology of the metaventral process, with a narrow anterior carina (blunt carina in H. multimaculatus ); the ventrite 1 exhibits a fine acuminate medial carina, slightly broadening posteriorly, not bifurcate posteriorly (carina narrowly Y-shaped, bifurcate posteriorly, in H. multimaculatus ); ventrite 2 with fine carina (wide carina in H. multimaculatus ); ventrites 3 and 4 flat, without carina (vestigial carinae in H. multimaculatus ); and aedeagus with parameres rounded at apex (apex acuminate in H. multimaculatus ) and appendices of the median lobe shorter than median lobe (as long as median lobe in H. multimaculatus ).

Figures

FIGURES 8–14. Hemiosus quindiensis, sp. nov., 8: dorsal habitus; 9: mesoventral process in ventral view; 10: mesoventral process in lateral view; 11: metaventral process in ventral view; 12: abdominal ventrites in ventral view; 13: left elytron in lateral view; 14: aedeagus in ventral view. Scale: fig. 8 = 1 mm, fig. 13 = 1 mm, fig. 14 = 0.1 mm.

FIGURES 15–16. Habitat of Hemiosus molanoi sp. nov. and Hemiosus quindiensis sp. nov.: 15: Colombia, Quindío Department, Córdoba Municipality, Río Verde; 16: Colombia: Quindío Department: La Tebaida Municipality, Pizamal, type locality of both species.