Cryptic speciation in theMerodon luteomaculatuscomplex (Diptera: Syrphidae) from the eastern Mediterranean

Abstract

The Merodon aureus group is characterized by high endemism and the presence of morphologically cryptic species. Within one of its subgroups, M. bessarabicus, seven species and four more species complexes have been described to date. One of these complexes, the M. luteomaculatus, comprises new taxa that are the subject of the present study. Its members have allopatric ranges restricted to the Balkan Peninsula and Aegean islands. This complex exhibits morphological variability that could not be characterized using a traditional morphological approach. Thus, we used integrative taxonomy with independent character sets (molecular, geometric morphometric, distributional) to delimit species boundaries. Data on three molecular markers (COI, 28S rRNA, and ISSR) and geometric morphometry of the wing and male genitalia, together with distributional data, enabled recognition of six cryptic species within the complex: M. andriotes sp. n., M. euri sp. n., M. erymanthius sp. n., M. luteomaculatus sp. n., M. naxius sp. n., and M. peloponnesius sp. n. We discuss the possible influence of Aegean paleogeographical history on the speciation of this complex.

First record of the bacterial endosymbiont Wolbachia for phytophagous hoverflies from genus Merodon (Diptera: Syrphidae)

“…; Radenković et al . ). However, subtle differences in wing and surstylus shape were detected using geometric morphometry (see Ačanski et al .…”

“…; Radenković et al . ). Maximum likelihood (ML) analysis of COI sequences including representatives of all potential complexes from M. aureus species group revealed deep divergences between morphologically close species (Fig.…”

“…The members of the taxa are small sized (8-13 mm), with a short, rounded abdomen, a distinct spike on the metatrochanter in males and a characteristic structure of the male genitalia Radenkovi c et al 2011). Until recently, the group comprised altogether 18 previously known and newly discovered taxa from the Mediterranean region and southern European mountain regions (Marcos-García et al 2007;Vuji c et al 2007;Milankov et al 2008;Radenkovi c et al 2011;Speight 2014); however, new data indicate the presence of additional species (Šaši c et al 2016;Veseli c et al 2017;Radenkovi c et al 2018;Šaši c Zori c et al 2018).…”

“…The first results about the molecular diversity of the M. aureus group were based on analyses of 3 0 and 5 0 fragments of the mitochondrial DNA (mtDNA) COI gene and suggested the presence of multiple cryptic species complexes within the group. The morphological character states usually used in taxonomy of hoverflies mostly failed to discern these potential species (Šaši c et al 2016;Radenkovi c et al 2018). However, subtle differences in wing and surstylus shape were detected using geometric morphometry (see A canski et al 2016;Šaši c et al 2016;Radenkovi c et al 2018).…”

“…The morphological character states usually used in taxonomy of hoverflies mostly failed to discern these potential species (Šaši c et al 2016;Radenkovi c et al 2018). However, subtle differences in wing and surstylus shape were detected using geometric morphometry (see A canski et al 2016;Šaši c et al 2016;Radenkovi c et al 2018). Maximum likelihood (ML) analysis of COI sequences including representatives of all potential complexes from M. aureus species group revealed deep divergences between morphologically close species (Fig.…”