Rumilara riberai, Linský & Čiamporová-Zaťovičová & Laššová & Čiampor Jr, 2022

Linsky, Marek, Ciamporova-Zatovicova, Zuzana, Lassova, Kristina & Ciampor Jr, Fedor, 2022, Molecular phylogeny of the riffle beetle genus Hexanchorus revealed a presence of a new genus (Coleoptera: Elmidae), Arthropod Systematics & amp; Phylogeny 80, pp. 575-602 : 575

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.

Figures

Figure 2. Dorsal habiti of Rumilara gen. nov. species: a R. obscura sp. nov. male holotype; b R. suppressa sp. nov. male holotype; c R. riberai sp. nov. male holotype; d R. paterna sp. nov. male holotype; e R. leleupi comb. nov. male holotype. Scale: 0.5 mm.

Figure 3. Lateral habiti of Rumilara gen. nov. species. a R. obscura sp. nov. male holotype; b R. suppressa sp. nov. male holotype; c R. riberai sp. nov. male holotype; d R. paterna sp. nov. male holotype; e R. leleupi comb. nov. male holotype. Scale: 0.5 mm.

Figure 5. Antennae of Rumilara gen. nov. and Hexanchorus: a R. obscura sp. nov.; b R. suppressa sp. nov.; c R. riberai sp. nov.; d R. paterna sp. nov.; e R. leleupi comb. nov.; f H. mcdiarmidi; g H. virilis; h H. shannoni; i H. angeli; j H. rostratus; k H. cordillierae; l H. onorei; m H. tarsalis; n H. usitatus; o H. gracilipes; p H. caraibus; q H. crinitus; r H. dimorphus; s H. emarginatus; t H. browni. (a, k based on dissected antennae; b-j, l-r based on photographs, not to scale, setae omitted).

Figure 6. Pronota of Rumilara gen. nov. species: a R. obscura sp. nov. male holotype; b R. suppressa sp. nov. male holotype; c R. riberai sp. nov. male holotype; d R. paterna sp. nov. male holotype; e R. leleupi comb. nov. male holotype. Scale: 0.2 mm.

Figure 7. Ventral habiti of Rumilara gen. nov. species: a R. obscura sp. nov. male paratype; b R. suppressa sp. nov. male paratype; c R. riberai sp. nov. female paratype; d R. paterna sp. nov. paratype; e R. leleupi comb. nov. male holotype. Scale: 0.5 mm.

Figure 8. Abdomens of Rumilara gen. nov. species: a R. obscura sp. nov. male holotype; b R. suppressa sp. nov. male holotype; c R. riberai sp. nov. male holotype; d R. paterna sp. nov. male holotype; e R. leleupi comb. nov. male holotype. 0.2 mm.

Figure 9. Larvae of Rumilara gen. nov. species: a R. obscura sp. nov., dorsal; b R. suppressa sp. nov., dorsal; c R. riberai sp. nov., dorsal; d R. paterna sp. nov., dorsal; e R. obscura sp. nov., ventral; f R. suppressa sp. nov., ventral. Scale: 1 mm.

Figure 10. Larva of Rumilara obscura sp. nov. (a - d): a prosternum and mesosternum; b foreleg (without coxa); c midleg; d hindleg. Schematic illustrations: e midleg of Hexanchorus cordillierae (alp - anterior lateral pubescence; mst - mesotibial tubercle; plp - posterior lateral pubescence; vs - ventral seta); f aedeagus of Rumilara riberai sp. nov. (ap - apophyse; co - corona; df - dorsal fibula; en - endophallus; mi - fibula minor; mj - fibula major; ml - median lobe; pa - paramere; ph - phallobase). Scale: 0.1 mm.

Figure 13. Rumilara riberai sp. nov.: a aedeagus, left lateral view; b aedeagus, ventral view; c aedeagus, right lateral view; d ovipositor; e male sternite VIII; f female sternite VIII. Scale: 0.1 mm.

Figure 16. Sampling sites of Rumilara gen. nov. in Ecuador: a Cotopaxi prov., Otonga env., Rio Esmeralda; b Cotopaxi prov., Artos env., stream above confluence with Rio Esmeralda; c Santo Domingo de los Tsachilas prov., Otongachi env., tributary of Rio Toachi; d Santo Domingo de los Tsachilas prov., thin water layer on rock, Otongachi env.; e Morona-Santiago prov., small stream near Indanza; f Morona-Santiago prov., Santa Rosa de Mamanguy env., Cascada la Encanada; g fast-flowing stream in Napo prov.; h Morona-Santiago prov., tributary of Rio Tinajillas; i Morona-Santiago prov., tributary of Rio Tinajillas; (localities of R. obscura - a, b; R. riberai - c, d; R. paterna - e, f; R. suppressa - g - i).