Our scientific articles

1. Comparative phylogeography and integrative taxonomy of Ochlerotatus caspius (Diptera: Culicidae) and Ochlerotatus dorsalis

Abstract

Given that accurately identifying pathogen vectors is vital for designing efficient mosquito control programs based on the proper surveillance of the epidemiologically important species, it has been suggested the complementary use of independently evolving genes and morphometric traits as a reliable approach for the characterization and delimitation of related species. Hence, we examined the spatial distribution of COI mtDNA and ITS2 rDNA variation from the historical perspective of Ochlerotatus caspius (Pallas, 1771) and O. dorsalis (Meigen, 1830), while simultaneously testing the utility of the two markers in integrative species delimitation when combined with phenotypic character analyses of larvae and adults. Despite the striking difference in haplotype diversity (high in COI mtDNA, low in ITS2 rDNA), no evident phylogeographic structure was apparent in the Palearctic O. caspius. The Holarctic O. dorsalis species was subdivided into two highly distinctive COI mtDNA phylogroups which corresponded to the Nearctic and Palearctic regions. Strong support for the independence of the two allopatric evolutionary lineages suggested that geographical barrier and climatic changes during Pleistocene caused vicariance of the ancestral range. COI mtDNA reliably distinguished O. caspius and O. dorsalis, while ITS2 rDNA yet again lacked the proper resolution for solving this problem. An integrative approach based on the larval and adult morphological traits have varying taxonomic applications due to their differential diagnostic values. Thus, by the implementation of an integrative taxonomic approach, we successfully detected species borders between the two epidemiologically relevant species and uncovered the presence of cryptic diversity within O. dorsalis.

Full article

2. Toward the conservation of the endemic monotypic fish genus Aulopyge from the Balkan Dinaric karst: Integrative assessment of introduced and natural population

Abstract

The complex biogeographical history of the Balkan Peninsula caused remarkable freshwater fish diversity and endemism, among which Cyprinidae fish dominate. The Dinaric karst was a Pleistocene refugium and it harbors ancient and endemic cyprinids, including Aulopyge huegelii, a sole representative of its genus. Being highly distributionally restricted, it faces various threats that promote a critical decline in population abundance and even population extinction. Phenotypic and molecular diversity of the introduced (Šator Lake, Šator Mountain) and natural (Studena River, Duvanjsko Polje) populations of Dalmatian barbelgudgeon from Bosnia and Herzegovina was studied by using two mitochondrial genes and morphometric traits (linear and geometric morphometrics). Nonparametric ANOVA showed that two analyzed populations significantly differed in six linear measurements, except snout length and postorbital head length. Contrary to centroid size, two populations were found to be significantly different in body shape. Deformation grids indicated that individuals from Studena River are characterized by wider and slightly shorter body comparing to individuals from Šator Lake. Incongruence in cytochrome c oxidase subunit I (COI) and cytochrome b (cyt b) mitochondrial DNA (mtDNA) variation was observed since a common COI haplotype was observed, while four and three cyt b haplotypes were registered in Šator Lake and Studena River, respectively. Since it was demonstrated that cyt b mtDNA was a faster evolving gene, we encourage its use in intraspecies studies, especially for evaluating the connectivity of fragmented populations and for studying the evolutionary footprint of the processes incorporated into the distinctive evolution of Aulopyge. Finally, findings herewith provide a firm basis for designing a long‐term sustainable conservation strategy for endemic species in Dinaric karst.

Full article

3. DNA barcode assessment and population structure of aphidophagous hoverfly Sphaerophoria scripta: Implications for conservation biological control

Abstract

With the advent of integrated pest management, the conservation of indigenous populations of natural enemies of pest species has become a relevant practice, necessitating the accurate identification of beneficial species and the inspection of evolutionary mechanisms affecting the long‐time persistence of their populations. The long hoverfly, Sphaerophoria scripta, represents one of the most potent aphidophagous control agents due to a worldwide distribution and a favorable constellation of biological traits. Therefore, we assessed five European S. scripta populations by combining molecular (cytochrome c oxidase subunit I‐ COI, internal transcribed spacer 2‐ ITS2, and allozyme loci) and morphological (wing size and shape) characters. COI sequences retrieved in this study were conjointly analyzed with BOLD/GenBank sequences of the other Sphaerophoria species to evaluate whether COI possessed a sufficient diagnostic value as a DNA barcode marker to consistently delimit allospecific individuals. Additionally, the aforementioned characters were used to inspect the population structure of S. scripta in Europe using methods based on individual‐ and population‐based genetic differences, as well as geometric morphometrics of wing traits. The results indicate numerous shared COI haplotypes among different Sphaerophoria species, thus disqualifying this marker from being an adequate barcoding region in this genus. Conversely, the analyses of population structuring revealed high population connectivity across Europe, therefore indicating strong tolerance of S. scripta to environmental heterogeneity. The results imply a multilocus approach as the next step in molecular identification of different Sphaerophoria species, while confirming the status of S. scripta as a powerful biocontrol agent of economically relevant aphid pests.

Full article