Disentangling a cryptic species complex and defining new species within the Eumerus minotaurus group (Diptera: Syrphidae), based on integrative taxonomy and Aegean palaeogeography

Abstract

This study provides an overview of the Eumerus minotaurus taxon group, diagnosing a new species, E. anatolicus Grković, Vujić and Radenković sp. n. (Muğla, Turkey), and unraveling three cryptic species within E. minotaurus: E. karyates Chroni, Grković and Vujić sp. n. (Peloponnese, Greece), E. minotaurus Claussen and Lucas, 1988 (Crete and Karpathos, Greece) and E. phaeacus Chroni, Grković and Vujić sp. n. (Corfu and Mt Olympus, Greece; Mt Rumija, Montenegro). We applied an integrative taxonomic approach based on molecular, morphological and wing geometric morphometric data to corroborate and delimit cryptic species within the complex. In addition, we discuss the latent biogeographic patterns and speciation processes leading to configuration of the E. minotaurus group based on palaeogeographic evolution of the Aegean. Mitochondrial phylogeographic analysis suggested that speciation within the E. minotaurus group is attributable to formation of the mid-Aegean Trench and Messinian Salinity Crisis, and was integrated at the Pleistocene. We show that more accurate estimates of divergence times may be based on geological events rather than the standard arthropod mtDNA substitution rate.

A new species of Eumerus (Diptera, Syrphidae) from the Kingdom of Bhutan, the easternmost representative of the bactrianus subgroup

“…There are over 300 valid species of Eumerus described (Evenhuis and Pape 2019) and taxonomical difficulties abound, mainly due to the large number of species as well as the lack of comprehensive keys. Fortunately, in recent times more and more species groups have been treated integrally, where morphology is often supplemented by molecular characters (Grković et al 2015(Grković et al , 2017(Grković et al , 2019Chroni et al 2017Chroni et al , 2018. One such species cluster is the bactrianus subgroup of the Eumerus strigatus group as defined by Grković et al (2019).…”

Two new European long-legged hoverfly species of the Eumerus binominatus species subgroup (Diptera, Syrphidae)

“…The European fauna is fairly well known, although even here new species are regularly found, especially in the Mediterranean. Since 2010 no less than 17 species have been described from southern Europe and the adjacent Middle East (Ricarte et al 2012, 2018; Grković et al 2015, 2017, 2019; Markov et al 2016; Smit et al 2017; Steenis et al 2017; Chroni et al 2018) and many more await description.…”

“…The members of Eumerus recorded in Southeast Europe belong to the following groups, identified on the basis of molecular markers in Chroni et al (2017) as well as on the basis of morphological similarity: tricolor (Chroni et al 2017; Grković et al 2017), strigatus with subgroup bactrianus (Speight et al 2013; Grković et al 2017, 2019), clavatus (Grković et al 2017), minotaurus (Chroni et al 2018), barbarus (van Steenis et al 2017), olivaceus , ornatus , obliquus (Smit et al 2017), basalis and pulchellus . The Eumerustricolor species group, defined by Chroni et al (2017) based on DNA sequencing and described by Grković et al (2017) displays a wide spectrum of species, but is clearly separated from the other members of the genus by a set of apomorphic characters, including a radially wrinkled basoflagellomere and a fossette clearly expressed, most often with partially to completely red abdominal tergites, but also includes species without red markings.…”

A new species of the genus Eumerus Meigen, 1822 (Diptera: Syrphidae) from Turkmenistan

“…The larvae of these hoverflies breed usually in bulbs and other succulent organs of the angiosperms, and some are known as pests of cultivated plants (Pérez-Bañón & Marcos-García, 1998;Ricarte et al, 2017;Piwowarczyk & Mielczarek, 2018). The species diversity of the genus is the main reason of increased attention from taxonomists (Grković et al, 2015(Grković et al, , 2017Chroni et al, 2018;Grković et al, 2019a, b). There are some distinct species-groups within the genus, but other members of the genus are distinguished by a unique combination of characters as the species described below.…”