Andrijana Andrić

Systematics and taxonomy of the ruficornis group of genus Merodon Meigen (Diptera: Syrphidae)

We revise the ruficornis group of species of Merodon Meigen (Diptera, Syrphidae) providing an illustrated key, a discussion of taxonomic characters and a morphological diagnosis. A total of 18 species from the ruficornis group are treated including distributional data. Descriptions are provided for seven new species: M. gallicus Vujić & Radenkovićsp.n., M. hoplitis Hurkmans sp.n., M. lamellatus Vujić & Radenkovićsp.n., M. nigripodus Vujić & Hayat sp.n., M. ovaloides Vujić & Radenkovićsp.n., M. ponticus Vujić & Radenkovićsp.n., and M. turcicus Vujić & Hayat sp.n. The taxon M. auripes Sack, is redefined and a neotype designated. Lectotypes are designated for M. graecus Loew; M. planiceps Loew and M. crymensis Paramonov. The monophyly and systematic position of this species group was assessed based on parsimony and maximum likelihood analyses of mitochondrial COI and nuclear 28S rDNA sequences. A very high level of endemism was observed in the ruficornis species group. Among 18 taxa, 12 are limited‐range endemics, present in few mountain areas or in a small part of the total range of the group. These endemics clearly show the importance of geographic isolation in the process of speciation.

Biogeographical patterns of the genus Merodon Meigen, 1803 (Diptera: Syrphidae) in islands of the eastern Mediterranean and adjacent mainland

The objective of this study was to obtain a biogeographical perspective on the hoverfly genus Merodon (Diptera, Syrphidae) based on data from 32 islands in the Aegean and Ionian archipelagoes vis‐à‐vis the adjacent mainland. In this part of the world, the genus comprises 57 species, out of more than 160 species described worldwide. The importance of eco‐geographical variables (area, elevation, distance to the nearest island and distance to the nearest mainland) and the species–area relationship (SAR) were studied in order to explain patterns of species richness. All tests supported the dynamic equilibrium concept. The area and distance to closest island were found to be the most important drivers of species richness on the Aegean and Ionian archipelagoes. Out of three SAR models evaluated in this study, the exponential function fitted our data best. It was found that a power model with no intercept value (C = 1) performed even better by using symbolic regression for non‐linear equation optimisation. The cluster and null‐model analyses performed to detect inter‐island similarities and origins of the insular Merodon fauna indicated a clear influence of colonisation history of the species on different islands. The results imply that the current distributions of Merodon species in the study area exhibit the combined effects of historical and present‐day processes.

Pupal stages of three species of the phytophagous genus Merodon Meigen (Diptera: Syrphidae)

plants, are mostly unknown. All known immature stages of Merodon feed on underground storage organs (bulbs, rhizomes and corms) of geophytes of the families Asparagaceae, Iridaceae and Amaryllidaceae. Of 160 known Merodon species, to date, the pupal stages have been described for only four: M. equestris (Fabricius), M. bombiformis Hull, M. luteihumerus Marcos-García, Vujić Mengual, and M. geniculatus Strobl. During field investigations in Đerdap National Park, Serbia, Merodon puparia were found in the ground near the bulbs of Ornithogalum umbellatum L. (Asparagaceae). DNA barcoding revealed that they belonged to the species M. aureus Fabricius and M. avidus (Rossi). Analysis of museum material from the Bavarian State Collection of Zoology in Germany revealed the puparium of an additional species, M. rufus Meigen. In our study we provide for the first time descriptions of the puparia of these three Merodon species. The main diagnostic morphological characters of the pupal spiracles and posterior respiratory processes are described using scanning electron microscopy, and cephalopharyngeal skeletons using binocular microscopy. In addition, puparium morphology of M. aureus, M. avidus and M. rufus is compared with known puparia of four other Merodon species and with the third larval stage of M. hurkmansi Marcos-García, Vujić Mengual.

Deceptive taxonomic importance of the Ornithogalum (Asparagaceae) seed morphology

Ornithogalum taxonomy is under constant revision. Numerous studies relating to morphology, anatomy, cytology, seed micromorphology and molecular phylogenies have been published to date, yet the number of species within the genus continues to be debated. In the Mediterranean region and rest of Europe, the genus comprises c. 120 species that share many common characters. In published resources, seed morphology has mostly been designated as species specific, having low taxonomic value for higher systematics. However, our comparative review of the published data and additional comparative analyses of seed morphology, detailed here, has revealed some discrepancies and limitations in species identifications. Our study included 14 Ornithogalum species, sampled from the Balkan Peninsula and Pannonian Plain. The main aims of the study were to describe seed structure characteristics, determine features upon which species could be identified, and examine the taxonomic relevance of differentiating characteristics. We confirm considerable variability in seed dimensions and shape. Testa primary structure exhibits non-species-specific features and we identify secondary testa structure as being an additional parameter for seed description. Overall, we found that while it is possible to define particular seed morphology patterns, they are of limited value in the taxonomy of this genus.

The Phenolics of the Ornithogalum umbellatum L. (Hyacinthaceae): Phytochemical and Ecological Characterization.

Ornithogalum umbellatum L. is a widely distributed species in Europe, that exhibits considerable variability at ecological, morphological, anatomical, and karyological level. Previous reports of the chemical investigations among Ornithogalum species indicate significant diversity of the secondary metabolites, as well. Knowing that environment affects the phenolic composition in plants to a large extent, the main objective of the research was to define relationship between phytochemical and ecological characters. To estimate an environmental influence on these results, plant material was collected at four habitats that differ in ecological factors and belong to two biogeographical regions: the Balkan Peninsula and the Pannonian Plane. Measured phytochemical characters are yield of dry extract, total phenolic and flavonoid contents, the presence of selected phenolic compounds as well as free‐radical scavenging activity (neutralization of DPPH and OH radicals). Results revealed that all analyzed phytochemical parameters differ between investigated O. umbellatum samples. The moisture level of habitat has the highest correlation, either positive or negative, with most of phytochemical characters, and is followed by temperature and soil reaction. Light intensity and nitrogen level have mostly moderate correlation coefficient with phytochemical characters. More complex correlation is revealed between ecological factors and nine phenolic compounds, with three observed patterns of relationship.

Assessment of genetic diversity within the Merodon ruficornis species group (Diptera: Syrphidae) by RAPD analysis

As one of the most distinct groups in the hoverfly genus Merodon , the monophyletic ruficornis species group has been the focus of several studies using different approaches. Molecular methods have shown incongruences between morphological and molecular data. In the present study, we investigated four species of the Merodon ruficornis group (i.e. M. loewi , M. armipes , M. papillus and M. hoplitis ) with the aim of detecting intra- and interspecific genetic diversity, and we examined the usefulness of random amplified polymorphic DNA (RAPD) in an integrative taxonomic approach to species delimitation. Analysis of Nei’s genetic variation over all loci showed that genetic diversity for the analyzed Merodon species was h=0.24. Based on UPGMA, PCoA and Bayesian clustering analyses, our results clearly differentiated four groups that correspond to the four morphologically-defined Merodon species. Among the analyzed species, M. armipes and M. hoplitis showed the lowest level of genetic divergence; M. loewi was clearly separated from both M. armipes and M. papillus . Based on our data, we propose the use of RAPD-PCR as an additional tool for resolving taxonomic problems within Merodon . https://doi.org/10.2298/ABS160729131A Received: July 29, 2016; Revised: November 15, 2016; Accepted: December 5, 2016; Published online: December 8, 2016 How to cite: Andric A, Kocis-Tubic N, Đan M, Vujic A, Obreht Vidakovic D. Assessment of genetic diversity within the Merodon ruficornis species group (Diptera: Syrphidae) by RAPD analysis. Arch Biol Sci. 2017;69(3):553-60.

Anatomical characteristics of two Ornithogalum L. (Hyacinthaceae) taxa from Serbia and Hungary and their taxonomic implication

Abstract Anatomical characters of two morphologically similar Ornithogalum taxa, O. umbellatum and O. divergens, were investigated. An analysis of leaf and scapus cross-sections was performed on plants from ten populations from Serbia and Hungary, using light microscopy. The aim of this research was to give data about the qualitative and quantitative anatomical characteristics of these taxa, in order to evaluate their taxonomic significance and single out distinctive anatomical features, as well as to contribute to the knowledge of the genus Ornithogalum in the studied region. On the basis of the variability of anatomical characters, similar populations formed two clusters, joining the plants previously determined as O. divergens and O. umbellatum. The two taxa significantly differed for most of the quantitative leaf and scapus characters. Since only quantitative differences were recorded in this research, anatomical characters could not be solely used to separate these two taxa. However, the results of anatomical investigations are consistent with the results of previous morphological and genetic analyses; therefore anatomical parameters could be useful as additional taxonomic characters.