Sexual size and shape dimorphism, and allometric scaling in the pupal and adult traits of Eristalis tenax.

The patterns and amount of variation in size, shape, and/or life history traits between females and males are fundamentally important to gain the comprehensive understanding of the evolution of phenotypic diversity. In addition, the covariation of phenotypic traits can significantly contribute to morphological diversification and sexual dimorphism (SD). Using linear and geometric morphometrics, 237 Eristalis tenax specimens sampled from five populations were, therefore, comparatively assessed for the variation in sexual size dimorphism (SSD), sexual shape dimorphism (SShD), and life history traits, as well as for trait covariation (ontogenetic and static allometry). Pupal body, adult wing, and body mass traits were analyzed. Female-biased SSD was observed for pupal length, width, and centroid size, adult wing centroid size, mass, wing loading, and wing area. Conversely, pupal length/width ratio, developmental time, and mass were not found to be sexually dimorphic. Next, wing SShD, but not pupal body SShD was revealed, while allometry was found to be an important "determinant of SD" at the adult stage, with only a minor impact at the pupal stage. By comparing the patterns of covariance (based on allometric slope and intercept) between respective body mass and morphometric traits of pupae and adults, greater variation in allometric slopes was found in adult traits, while static allometries of the two stages significantly differed, as well. Finally, the results indicate that changes in the allometric intercept could be an important source of intraspecific variation and SD in drone fly adults.

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

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 (Sator Lake, Sator 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 Sator 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 Sator 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.

Comparative Phylogeography and Integrative Taxonomy of Ochlerotatus caspius (Dipera: Culicidae) and Ochlerotatus dorsalis.

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.

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

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.

The First Molecular and Phenotypic Characterization of the Invasive Population of Aedes albopictus (Diptera: Culicidae) from the Central Balkans.

Aedes (Stegomya) albopictus (Skuse 1984), the Asian tiger mosquito, represents the most invasive and one of the medically most important mosquito vectors. Although native to South East Asia, the species has recently spread globally, and was registered in the city of Novi Sad (Serbia, Central Balkans) in August 2018. We characterized the invasive population using phenotypic (wing size and shape) and molecular (nuclear, internal transcribed spacer 2- ITS2, and mitochondrial, cytochrome c oxidase subunit I- COI) markers. The results of phenotypic analyses indicated that the Serbian population could be differentiated from the native (Thailand) and invasive (Hawaii and Florida) populations due to restricted gene flow, founder effect, and supposed different strain origin. The Serbian population showed genetic homogeneity, indicative of a small founder number (bottleneck invasion model). Despite the incorporation of ITS2 GenBank sequences into the data set, neither spatial (Geneland) nor nonspatial (BAPS) genetic structuring analyses helped infer the Serbian population origin. However, the comparison of the retrieved COI haplotype with previously characterized mitogenomes indicated a temperate strain origin, capable of overwintering. Such findings suggest that the newly registered Ae. albopictus population could be able to establish itself since previous studies outlined Novi Sad as a suitable area.

Genetic and phenotypic variation in central and northern European populations of Aedes (Aedimorphus) vexans (Meigen, 1830) (Diptera, Culicidae).

The floodwater mosquito Aedes vexans can be a massive nuisance in the flood plain areas of mainland Europe, and is the vector of Tahyna virus and a potential vector of Dirofilaria immitis. This epidemiologically important species forms three subspecies worldwide, of which Aedes vexans arabiensis has a wide distribution in Europe and Africa. We quantified the genetic and phenotypic variation in Ae. vexans arabiensis in populations from Sweden (northern Europe), Hungary, and Serbia (central Europe). A landscape genetics approach (FST , STRUCTURE, BAPS, GENELAND) revealed significant differentiation between northern and southern populations. Similar to genetic data, wing geometric morphometrics revealed two different clusters, one made by Swedish populations, while another included Hungarian and Serbian populations. Moreover, integrated genetic and morphometric data from the spatial analysis suggested groupings of populations into three clusters, one of which was from Swedish and Hungarian populations. Data on spatial analysis regarding an intermediate status of the Hungarian population was supported by observed Isolation-by-Distance patterns. Furthermore, a low proportion of interpopulation vs intrapopulation variance revealed by AMOVA and low-to-moderate FST values on a broader geographical scale indicate a continuous between-population exchange of individuals, including considerable gene flow on the regional scale, are likely to be responsible for the maintenance of the observed population similarity in Aе. vexans. We discussed data considering population structure in the light of vector control strategies of the mosquito from public health importance.

Shift in phenotypic variation coupled with rapid loss of genetic diversity in captive populations of Eristalis tenax (Diptera: Syrphidae): consequences for rearing and potential commercial use.

Because of its importance as a pollinator and its potential economic usefulness for the biodegradation of organic animal waste, the genetic and phenotypic diversity of the drone fly, Eristalis tenax L. (Diptera: Syrphidae), was studied in both wild and captive populations from southeastern Europe. Wild specimens from a natural protected habitat (with low human impact), field crop habitat (semisynanthropic condition), and intensive pig farming habitat (synanthropic condition) were compared with a laboratory colony reared on artificial media An integrative approach was applied based on allozyme loci, cytochrome c oxidase I mitochondrial DNA, wing traits (size and shape), and abdominal color patterns. Our results indicate that the fourth and eighth generations of the laboratory colony show a severe lack of genetic diversity compared with natural populations. Reduced genetic diversity in subsequent generations (F4 and F8) of the laboratory colony was found to be linked with phenotypic divergence. Loss of genetic variability associated with phenotypic differentiation in laboratory samples suggests a founder effect, followed by stochastic genetic processes and inbreeding. Hence, our results have implications for captive bred Eristalis flies, which have been used in crop pollination and biodegradation of organic waste under synanthropic conditions.

Genetic diversity and differentiation between Palearctic and Nearctic populations of Aedimorphus (=Aedes) vexans (Meigen, 1830) (Diptera, Culicidae).

Genetic diversity was studied at allozyme loci in two Palearctic and one Nearctic population of Aedimorphus (=Aedes) vexans, a species of public health and veterinary importance. The population from Serbia was the most polymorphic (P= 35%) with the highest observed heterozygosity (H(o) = 0.027). The lowest observed heterozygosity (H(o) = 0.010) was obtained for the Nearctic population. All analyses based on individual (STRUCTURE analysis) and population level (pairwise F(ST), Nm values, AMOVA, Nei's D value) revealed significant structuring between Nearctic and Palearctic populations, indicating a lack of gene flow and thus, the presence of independent gene pools. Taxon-specific alleles at the diagnostic Ao, Hk-2, Hk-3, Hk-4, Idh-1, and Idh-2 loci were used for identification and separation of Nearctic and Palearctic populations. Population genetics study provided valuable information on the correct distinction of Am. vexans populations and their adaptive potential that could find a future use in the studies of vector competence and development of vector-control strategies.

Wing geometric morphometric inferences on species delimitation and intraspecific divergent units in the Merodon ruficornis group (Diptera, Syrphidae) from the Balkan Peninsula.

A study of the Merodon taxa on the Balkan Peninsula, a region with a number of Pleistocene refugia, provides a useful framework for examining evolutionary processes and detecting hidden biodiversity. The phenotypic diversity of 22 samples of the Merodon ruficornis group on the Balkan Peninsula was examined using landmark-based geometric morphometrics. The boundaries of the species M. ruficornis, M. trebevicensis, M. auripes, M. armipes, and M. Ioewi were well defined based on wing shape and size. Canonical variate analysis showed that wing shape possessed sufficient differences to discriminate the species with a successful classification rate of 75-92% for males and 82-100% for females. The observed interspecific differentiation is generally in agreement with a previous study of the M. ruficornis group using a traditional morphological approach and molecular markers (allozyme loci, COI mtDNA). The spatial variability between conspecific populations and interpopulation variation were assessed based on both wing shape and size for male specimens. Phenotypically divergent units were delineated within previously defined species of the M. ruficornis group, indicating the possible presence of evolutionary independent units within the taxa analysed.