A revision of Onychelmis Hinton, 1941 (Coleoptera: Elmidae), with description of new species, DNA barcoding and notes on the geography of the genus

Abstract

The genus Onychelmis Hinton, 1941 was for a long time regarded as a small taxon with only three known species distributed in the Andes. A study of new material from Ecuador, using morphological and molecular data, has resulted in the discovery of five new species: Onychelmis lenkae sp. nov., O. lobata sp. nov., O. minor sp. nov., O. onorei sp. nov. and O. splendida sp. nov. We also revised the entire genus and redescribed the three known species, O. longicollis (Sharp, 1882), O. leleupi Delève, 1968 and O. whiteheadi Spangler & Santiago, 1991. Habitus photographs of adults are provided, together with line drawings of male and female genitalia, and schematic illustrations of the distribution of femoral tomentum for each species. DNA sequences for barcoding the COI mtDNA fragment were used to support species delimitation and to suggest possible relationships among species. The revision includes a key to adults of all species of Onychelmis and notes on the biogeography of the genus, with an updated distribution map.

Molecular phylogeny of the riffle beetle genus Hexanchorus revealed a presence of a new genus (Coleoptera: Elmidae)

“…However, the study also showed how many gaps still exist in our knowledge of this specialized group of insects, so closely tied to globally threatened freshwater habitats. The use of molecular data in Elmidae taxonomy has been proven to work well in the past (e.g., Linský et al 2021). The combination of DNA characters and morphological characterization contributed significantly to support the taxonomic claims presented here, again validating the feasibility of this approach and suggesting that it should become the standard for future studies of the diversity and evolution of these beetles.…”

“…The use of molecular data, or more specifically DNA barcoding, has significantly improved discriminatory power in revealing true species diversity and phylogenetic relationships. This is increasingly being confirmed also in the study of the Elmidae taxonomy (e.g., Čiampor Jr et al 2017Čiampor Jr et al , 2019Hayashi et al 2019;Linský et al 2019Linský et al , 2021. Unfortunately, we often encounter a lack of material suitable for DNA analysis as most known species are dry-pinned in museum collections, and the situation is similar in the genus Hexanchorus.…”

Spanglerelmis, a new genus of Elmidae (Insecta: Coleoptera) from Brazil with new species and biological notes

“…The knowledge of Neotropical Elmidae has increased in recent years with the description of several new species (Polizei & Barclay 2018, 2019a, 2019bLinský et al 2019Linský et al , 2021Polizei et al 2020aPolizei et al , 2020bČiampor et al 2021), and two new genera: Amazonopsis Barr, 2018 from Peru, Venezuela, and French Guiana; and Ictelmis Čiampor, Linský & Čiamporová-Zaťovičová reported from Ecuador. In Brazil, although new species have been regularly described in recent years (Polizei 2018a(Polizei , 2018bAlmeida et al 2020;Polizei et al 2020b;Polizei & Fernandes 2020;Polizei & Hamada 2021), the last genera, Tolmerelmis Hinton, 1972 andTyletelmis (Hinton, 1972), were described approximately 50 years ago.…”

Aquatic beetle diversity from Volcán Tacaná, Mexico: altitudinal distribution pattern and biogeographical affinity of the fauna

“…Note. This genus is distributed in Central and South America, contains eight described species (Linský et al 2021), and this study provides the northernmost point of its range.…”

“…Distribution. Mexico (new country record, Chiapas), Nicaragua, Panama, Colombia (González-Córdoba et al 2016;Linský et al 2021). Previous altitudinal records were from 1,219 to 1,828 m (González-Córdoba et al 2016;Linský et al 2021).…”