Onychelmis leleupi Delève, 1968

Linský, Marek, Čiamporová-Zaťovičová, Zuzana & Čiampor, Fedor, 2021, A revision of Onychelmis Hinton, 1941 (Coleoptera: Elmidae), with description of new species, DNA barcoding and notes on the geography of the genus, European Journal of Taxonomy 739 (1), pp. 1-35 : 11-13

publication ID

https://doi.org/ 10.5852/ejt.2021.739.1263

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scientific name

Onychelmis leleupi Delève, 1968


Onychelmis leleupi Delève, 1968 View in CoL

Figs 3A View Fig , 6A View Fig , 8 View Fig A–B, 10E, 11A, 12A–B

Onychelmis leleupi Delève, 1968: 217 View in CoL , figs 4–11.

Onychelmis leleupi View in CoL – González-Córdoba et al. 2016: 10, figs 5c–d, 6b–c.

Differential diagnosis

Onychelmis leleupi can be distinguished from all species of the genus by the combination of the following characters: 1) larger size (CL: 1.44–1.51 mm); 2) pro- and mesofemora with tomentum reaching around middle ( Fig. 6A View Fig ); 3) humeri produced; 4) prominent carina on sixth interval present; 5) elytral punctures shallowly impressed; 6) apeX of aedeagus trilobate ( Fig. 8 View Fig A–B).

Material examined

ECUADOR • 5 ♂♂, 10 ♀♀, 1 eX.; “Ecuador, Morona-Santiago prov., Limón env., Río Yungantza , 02°59′49.3″ S, 78°29′18.9″ W, 1522 m a.s.l., 27. 8. 2013, stream ca. 3 m wide, fast flowing, partly shaded, with boulders, stones, gravel, Čiampor & Čiamporová-Zaťovičová lgt.”; PUCE / CCB GoogleMaps .



BODY. Obovate, black ( Fig. 3A View Fig ); length 1.44–1.51 mm; width 0.66–0.68 mm; dorsum conveX, glabrous with sparse, light yellowish setae. Hairy or scale-like tomentum distributed on following areas: genae, sides of prosternum, mesoventrite, metaventrite and abdomen, epipleura, and medial and lateral portions on bases of femora.

COLOUR. Head, pronotum and elytra black; venter dark brown to black with reddish tinge; coxae, femora and tarsi dark brown with reddish tinge; trochanters and tibiae brown; basal segments of antennae and tarsal claws pale brown.

HEAD. Partly retractable into prothoraX, dorsally shiny. Antennae filiform, 11-segmented; pedicel about twice as long as scape; remaining segments about 4 times as long as scape and pedicel combined; segments 3–10 subrectangular, subequal in length; terminal segment longest, suboval, with pointed apex. Labrum with anterior margin very slightly emarginate medially; anterolateral angles broadly arcuate with numerous golden, recumbent hair-like setae; clypeus shorter and wider than labrum, about 3.5 times as wide as long, anterior margin slightly concave, anterolateral angles rounded; frontoclypeal suture almost straight. Eyes well developed, HW: 0.29–0.31 mm, ID: 0.13–0.15 mm, suboval in lateral view, protruding from head outline in dorsal view, circumocular surface raised. Frons convex between eyes.

THORAX. Pronotum widest behind middle, PW: 0.41–0.43 mm, PL: 0.66–0.68 mm; surface shiny, with microreticulation only along basal margin and posterolateral angles, with dense tiny punctures; sublateral carinae never well-developed, but a short, very fine raised line in basal ¼ present; disc conveX, divided by a broad, deep transverse impression before middle; two prescutellar foveae separated by a raised line extending from base to apical discal half, connecting both halves and merging into them; anterior margin arcuate; posterior margin bisinuate; sides of pronotum convex before and after transverse constriction; lateral margins narrowly rimmed; posterolateral angles orthogonal; anterolateral angles slightly produced. Hypomeron finely microreticulate, widest in middle. Prosternum moderately long in front of procoxae, with anterior margin concave; sides raised around procoxae, forming carinae, not reaching anterior margin, prosternal process long, moderately broad and with posterior margin broadly rounded. Mesoventrite coarse, short and wide, with deep triangular groove for reception of prosternal process; posterior margin around mesocoxae raised. Metaventrite slightly wider than long, wrinkled, more or less shiny; disc convex with deep, medial, triangular depression in posterior half; discrimen in basal ¾; with one prebasal fovea on each side. Elytra (EL: 0.96–0.99 mm, EW: 0.68–0.69 mm) conveX, widest in anterior ¾; sides strongly declivous; surface shiny, with dense tiny punctures; elytral margin narrowly rimmed; humeri protruding from outline; epipleuron tapering posteriorly. Prominent carina on siXth interval reaching ⅘ of elytron. Elytra with ten rows of small, shallowly impressed punctures, separated by 2–4 times puncture diameter, diminishing toward lateral margins and elytral apeX. Scutellum subovate, flat. Legs moderately long; femora clavate; tibiae longest. Protibiae with anterior cleaning fringe on apical ⅓; mesotibiae with two cleaning fringes – anterior on apical ⅕ and posterior on apical ⅓; metatibiae with posterior cleaning fringe on apical ⅓. Tarsi 5-segmented, first four segments each with one fine pale, recumbent seta, fifth segment slightly shorter than remaining segments combined; claws with a large subbasal and smaller basal teeth.

ABDOMEN. With 5 ventrites. First ventrite with basal margin broadly rounded; fifth ventrite longest, apically setose, with posterior margin broadly arcuate. Aedeagus ( Fig. 8 View Fig A–B) elongate. Penis without fibula; corona at apeX, well developed; in ventral view parallel-sided, apically eXtended, apeX rounded with medial projection; in lateral view slender, evenly narrowed from base to slightly curved apex. Parameres absent. Phallobase slightly longer than penis, parallel-sided, in ventral view straight, curved in lateral view.


Externally similar to male, except metaventrite without distinct medial, triangular depression in posterior half and without two prebasal foveae, fifth ventrite more elongate and eXtension of femoral tomentum slightly greater. Ovipositor ( Fig. 10E View Fig ) with very short, laterally curved stylus; preterminal segment long, narrow, widened at base, well sclerotized, about 10 times as long as stylus, with sparse curved blunt and acuminate spines; basal segment membranous, about as long as preterminal and distal segments combined, baculus curved, well sclerotized.


This species inhabits fast-flowing, mountain or submontane streams ( Fig. 11A View Fig ).


Known from Ecuador, Colombia and Peru ( Delève 1968; Shepard & Chaboo 2015; González-Córdoba et al. 2016) ( Fig. 12 View Fig A–B).


Central College, Bangalore














Onychelmis leleupi Delève, 1968

Linský, Marek, Čiamporová-Zaťovičová, Zuzana & Čiampor, Fedor 2021

Onychelmis leleupi

Gonzalez-Cordoba M. & Zuniga M. C. & Manzo V. & Giraldo L. P. & Chara J. 2016: 10

Onychelmis leleupi Delève, 1968: 217

Deleve J. 1968: 217
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