3.2.5. Rumilara riberai sp. nov.

Figs 2c, 3c, 5c, 6c, 7c, 8c, 9c, 10f, 13

Material examined.

Type material: Holotype ♂ (PUCE) " Ecuador, Santo Domingo de los Tsáchilas prov., Otongachi env., tributary of Rio Toachi, 00°19′59.7″ S, 78°56′26.6″ W, 917m a.s.l., 11.8.2013, stream ca 10m wide, with sand, gravel, boulders, Čiampor Jr & Čiamporová-Zaťovičová lgt." ; Paratypes 6♂♂, 1♀ (CCB), 3 ex with the same data as the holotype; 4♀♀, 6 ex " Ecuador, Santo Domingo de los Tsáchilas prov., Otongachi env., next to the tributary of Rio Toachi, 00°19′50.5″ S, 78°56′41.6″ W, 914m a.s.l., 11.8.2013, very shallow stream running along a rock covered by periphyton, Čiampor Jr & Čiamporová-Zaťovičová lgt." Other material: 13 larvae with the same data as the holotype; 6 larvae " Ecuador, Santo Domingo de los Tsáchilas prov., Otongachi env., next to the tributary of Rio Toachi, 00°19′50.5″ S, 78°56′41.6″ W, 914m a.s.l., 11.8.2013, very shallow stream running along a rock covered by periphyton, Čiampor Jr & Čiamporová-Zaťovičová lgt." ; 1 larva " Ecuador, Santo Domingo de los Tsáchilas prov., Otongachi env., tributary of Rio Toachi, 00°19′34.0″ S, 78°56′59.1″ W, 852m a.s.l., 11.8.2013, wild river ca 20m wide, fast flowing, with large boulders, Čiampor Jr & Čiamporová-Zaťovičová lgt." .

Adult diagnosis.

The species can be distinguished by a combination of following characters: 1) head only partially clothed by pubescence, clypeus bare; 2) femora bare or with a row of dark, long hairs on dorsal margin; 3) elytra without dense pubescence; 4) aedeagus with rod-like sclerite; 5) parameres only feebly asymmetrical.

Adult diagnostic description.

Male. Colour: Body (Figs 2c, 3c) black; lateral sides of femora and tibiae brown; tarsal claws pale brown with reddish tincture. Pubescence: Head behind eyes clothed with short, prone pubescence. Elytra very readily covered by short, recumbent pubescence, and with numerous moderately long, curved, semi-erect, hair-like setae. Femora with long, dark, densely set, hair-like setae near dorsal margin; pro- and metatibiae apically with a fringe of long, dark, hair-like setae on inner margin; mesotibiae without pubescence. Metaventrite readily clothed with short, prone pubescence. Surface: Head, clypeus and pronotum densely punctate. Elytra with rows of punctures moderately deeply impressed; third interval slightly elevated in anterior 1/5; remaining intervals nearly flat. Prosternal process (Fig. 7c) moderately wide, concave between procoxae, then subtriangular with rounded apex. Aedeagus (Figs 13a-c) with long, dorsal, rod-like sclerite on penis; parameres asymmetrical, left one slightly longer. - Female externally similar to male, except slightly larger.

Measurements.

♂ - CL: 2.16-2.53 mm; PL: 0.56-0.65 mm; PW: 0.71-0.79 mm; EL: 1.60-1.88 mm; EW: 0.83-0.97 mm. ♀ - CL: 2.68-2.69 mm; PL: 0.68-0.70 mm; PW: 0.82-0.85 mm; EL: 1.99-2.00 mm; EW: 1.04-1.06 mm.

Variation.

The greatest differences were observed in distribution of pubescence (mainly on legs, around eyes, partly on pronotum and elytra) due to its often removal.

Etymology.

Named after Ignacio Ribera Galán a great expert on systematics, phylogeny, evolution, biogeography, and conservation of water beetles, who untimely passed away.

Larva

(Fig. 9c) with length 2.92-2.96 mm, greatest width 0.96-0.99 mm. Pleurites on abdominal segments 1-5. Abdominal segments 1-6 explanate. Surface around the frontal pair of pronotal gibbosities of the same colour as the rest of pronotum. Tergum of abdominal segments 1-7 with a pair of distinct, longitudinally arranged small gibbosities.

Distribution.

Known from three localities in Santo Domingo de los Tsáchilas Province (Figs 16c-d).

Remarks.

Several paratypes are markedly smaller than the rest (including holotype), however, they agree in all diagnostic characters.