Hexanchorus virilis, Linsky, Marek, Ciamporova-Zatovicova, Zuzana & Ciampor Jr, Fedor, 2019

Linsky, Marek, Ciamporova-Zatovicova, Zuzana & Ciampor Jr, Fedor, 2019, Four new species of Hexanchorus Sharp from Ecuador (Coleoptera, Elmidae) with DNA barcoding and notes on the distribution of the genus, ZooKeys 838, pp. 85-109 : 91-94

Hexanchorus virilis sp. n. Figs 3, 4, 14, 15, 25, 26, 36

Material examined.

Holotype (PUCE) ♂: "Ecuador, Pastaza prov., Río Uklan, 01°17 ’13.8” S, 77°38 ’52.5” W 468m a.s.l., 18.8.2013, bigger river with lowland character, stream ca 15m wide, slow flowing with small riffles, with boulders, rock tables and sand, Čiampor & Čiamporová-Zaťovičová lgt.". Paratypes (PUCE, NMW, CCB): 10 ♂♂ with the same locality as holotype.

Diagnosis.

Hexanchorus virilis sp. n. can be distinguished from all species of the genus by combination of the following male characters: 1) smaller size (CL: 2.78 - 2.97 mm); 2) protibiae apically dilated; 3) mesotibiae with medial pubescent area long, reaching to 2/4 of tibia and lateral pubescent area short, only in first fourth; 4) mesotibiae with small tubercle on inner apex; 5) metatibiae with indistinct tubercle on inner apex; 6) elytra with rounded apices; 7) fifth ventrite moderately deeply but narrowly emarginate; 8) aedeagus with slightly zagged apical portion in ventral view.

Description.

Male. Body elongate, subparallel, dorsum moderately convex (Fig. 3). Length (CL) 2.78 - 2.97 mm; greatest width (EW) 1.02 - 1.07 mm, dorsal side dark brown with greenish iridescence; venter brown to almost black, tarsal claws reddish-brown. Dorsal surface densely covered with short recumbent setae and sparser, longer, dark, semi-erect setae; ventral surface densely covered with longer, golden, recumbent setae, especially on trochanters.

Head partly retractable into prothorax. Clypeus with anterior margin straight, about three times wider than long, shorter and narrower than labrum. Labrum feebly emarginate anteromedially, expanded laterally with sides broadly rounded, densely setose. Frontoclypeal suture visible, almost straight. Eyes suboval in lateral view, protruding from head outline, bordered by long black curved setae ( “eyelashes”) that arise near dorsal and ventral sides of eyes and extend toward middle of eye. Antenna moniliform, 11-segmented, pubescent; first two segments with dense long, dark brown setae, rest of antenna with only few such setae on sides; scape curved, about twice as long as pedicel, remaining segments about three times longer than first and second combined; segments 3-10 short, subtriangular; terminal segment subglobular with slightly pointed apex. Pronotum (PL) 0.65 - 0.69 mm long, widest (PW: 0.81 - 0.83 mm) at base; with complete transversal depression at apical third and small basolateral impressions, with two prescutelar foveae; sublateral carinae absent; lateral margins convex before and after depression, basal angles slightly projected outwards; disc raised with concave sides near base; two tiny depressed dots medially near base; middle portion of base produced posteriorly; basal margin straight on sides, broadly rounded before scutellum. Scutellum subtriangular. Hypomeron narrow, straight. Prosternum extremely short in front of procoxae; prosternal process parallel-sided, apical portion subtriangular. Mesoventrite short with a deep, broad, V-shaped depression for reception of prosternal process. Metaventrite long and wide, slightly depressed along midline; discrimen thin and long, reaching abdomen. Legs slender, long. Procoxae and mesocoxae rounded, metacoxae transverse. Forelegs shortest, with all segments slightly wider than remaining pairs. Protibiae apically widened, emarginated before apex. Mesotibiae with medial pubescent area long, reaching to 2/4 of tibia and lateral pubescent area short, only in first fourth. Mesotibiae with small tubercle on inner apex, metatibiae with small tubercle on inner apex. Tarsi simple, fourth tarsal segment with fine, nearly erect setae ventrally, fifth segment longest. Tarsal claws long and stout.

Elytra (EL) 1.91 - 2.16 mm long, widest (EW: 1.02 - 1.07 mm) across humeri; subparallel in anterior 4/5, with ten rows of small punctures forming striae; punctures separated by a distance three to four times the puncture diameter; humeral area slightly swollen. First four or five striae distinct, in nearly straight lines, remaining ones feebly visible, obscured apically. Epipleuron thin, widest in anterior third. Apical margin of elytra narrowly rounded.

Abdomen with five clearly visible ventrites (Fig. 14). Intercoxal process subtriangular with rounded apex. First three ventrites depressed medially; fifth ventrite moderately deeply but narrowly emarginate. Cuticle densely covered with short, golden, recumbent setae. Aedeagus (Figs 25, 26) elongate. Penis in ventral view subparallel with long apophyses, apical part slightly zagged, firstly wide then strongly narrowing into long apical portion with rounded apex, in lateral view slender, sinuate, with widened basal third; with corona membranous, fibula not visible, curved oblong sclerotized structure present in middle. Parameres asymmetrical, about 1.5x shorter than penis, in lateral view subparallel, widest in middle, feebly tapering towards rounded apex, skewed on one side, in ventral view jointed in middle, with rounded apex. Phallobase parallel-sided, feebly curved in lateral view. Penis and parameres with sparse fine spines.

Female. Even females were collected at the same locality as males, we failed to get molecular data from them to confirm their conspecificity. Due to that we refrained from formal description of females and including them in the type series, but we provide their habitus photographs (Figs 4, 15).

Variation. We observed variation in size, color from dark brown to brown and pubescence, especially on abdominal sterna. Scale of green iridescence differed substantially.

Etymology.

Latin, virilis (manly, masculine, virile), in reference to male sexual dimorphism.

Distribution.

Known only from the one locality in Pastaza Province (Fig. 36).