An overlooked case for a century: taxonomy and systematics of a new Iberian species of Eumerus Meigen, 1822 (Diptera, Syrphidae)

Abstract

The hoverfly genus Eumerus Meigen, 1822 (Eristalinae: Merodontini) comprises 250+ described species, of which 36 are reported from the Iberian Peninsula. The high species diversity linked to the low degree of morphological differentiation between some species, which is even lower in females, leads to a high taxonomic complexity in this genus. The aim of this work is to confirm the morphological and molecular validity of an undescribed species of Eumerus, which is widespread in the Iberian Peninsula. The new species is described and compared with similar species. The genitalia of the new species are similar to those of Eumerus clavatus Becker, 1923 and Eumerus uncipes Rondani, 1850, but also share some features with Eumerus nudus Loew, 1848. The COI-5’ barcode is provided for the new taxon and analysed together with those of other named Eumerus sequences/species publicly available online. In the light of the morphology and barcoding data, the systematic position of the new species is discussed.

National records of 3000 European bee and hoverfly species: A contribution to pollinator conservation

“…Knowledge on the taxonomy, ecology and distribution of many taxa encompassed by this study is of course prone to changes in the future. Taxonomic revisions are still an ongoing process for some challenging groups, such as the bee genera Andrena Fabricius, 1775 (Praz et al, 2022; Wood, 2021; Wood et al, 2021), Dasypoda Latreille, 1802 (Ghisbain et al 2023; Radchenko, 2016, 2017; Radchenko et al, 2019), Nomada Scopoli, 1770 (Smit, 2018), Osmia Panzer, 1806 (Müller, 2018, 2022b) and Hoplitis Klug, 1807 (Müller, 2014a; Müller & Mauss, 2016); and the hoverfly genera Merodon Meigen, 1803 (Vujić, Tot, et al 2021; Vujić, Likov, et al, 2021; Vujić, Radenković, et al, 2020; Vujić, Radenković, et al, 2021; Vujić, Speight, et al, 2020) and Eumerus Meigen, 1822 (Aguado‐Aranda et al, 2022; Grković et al, 2019, 2021). In these groups, the number of described species (including cryptic ones) is continuously increasing in part thanks to increased access to a large array of diagnostic methods such as DNA barcoding, semio‐chemical analysis and geometric morphometrics.…”

Are Appearances Deceiving? Morpho-Genetic Complexity of the Eumerus tricolor Group (Diptera: Syrphidae) in Europe, with a Focus on the Iberian Peninsula

“…The Ibero-Balearic region (mainland Portugal and Spain, plus Andorra, Gibraltar and the Balearic Islands) hosts a great diversity of hoverflies, with 420+ species recorded [18][19][20][21]. The genus Eumerus is particularly diverse in the Ibero-Balearic region, with 37 species reported, of which 7 are endemic [22][23][24]. Nowadays, 9 species groups and a number of "individual species" (not assigned to a species group) have representation in the Ibero-Balearic area, with the E. tricolor group having the highest number of species included [22,24] Recent findings of new species of Eumerus in the Iberian Peninsula [14,[23][24][25] suggest that the Eumerus diversity from this area might be underestimated, especially for the highly diverse E. tricolor group, which has been poorly explored in this region.…”

“…The genus Eumerus is particularly diverse in the Ibero-Balearic region, with 37 species reported, of which 7 are endemic [22][23][24]. Nowadays, 9 species groups and a number of "individual species" (not assigned to a species group) have representation in the Ibero-Balearic area, with the E. tricolor group having the highest number of species included [22,24] Recent findings of new species of Eumerus in the Iberian Peninsula [14,[23][24][25] suggest that the Eumerus diversity from this area might be underestimated, especially for the highly diverse E. tricolor group, which has been poorly explored in this region. Thus, in the framework of an ongoing taxonomic revision of the Ibero-Balearic Eumerus, the objectives of the present work are to assess the diversity of this species group and to explore the taxonomy and systematic position of its species through an integrative approach.…”

“…The Ibero-Balearic region (mainland Portugal and Spain, plus Andorra, Gibraltar and the Balearic Islands) hosts a great diversity of hoverflies, with 420+ species recorded [ 18 , 19 , 20 , 21 ]. The genus Eumerus is particularly diverse in the Ibero-Balearic region, with 37 species reported, of which 7 are endemic [ 22 , 23 , 24 ]. Nowadays, 9 species groups and a number of “individual species” (not assigned to a species group) have representation in the Ibero-Balearic area, with the E. tricolor group having the highest number of species included [ 22 , 24 ]: Eumerus azabense Ricarte & Marcos-García in Ricarte et al, 2018, Eumerus grallator Smit in Grković et al, 2019a, Eumerus grandis Meigen, 1822, Eumerus hispanicus van der Goot, 1966, Eumerus larvatus Aracil, Grković & Pérez-Bañón in Aracil et al, 2023, Eumerus ovatus Loew, 1848, Eumerus sabulonum (Fallén, 1817), Eumerus tarsalis Loew, 1848 and E. tricolor .…”

“…Recent findings of new species of Eumerus in the Iberian Peninsula [ 14 , 23 , 24 , 25 ] suggest that the Eumerus diversity from this area might be underestimated, especially for the highly diverse E. tricolor group, which has been poorly explored in this region. Thus, in the framework of an ongoing taxonomic revision of the Ibero-Balearic Eumerus , the objectives of the present work are to assess the diversity of this species group and to explore the taxonomy and systematic position of its species through an integrative approach.…”