Suchergebnisse

The genus Merodon Meigen, 1803 is the largest European hoverfly genus, widely distributed around the Palaearctic and Afrotropical regions. Larvae of Merodon are phytophagous, feeding on buried plant storage structures, often bulbs of plants pollinated by the adults. The larval morphology and habits of most species remain unknown. Merodon planifacies Bezzi, 1915, belongs to the Afrotropical lineage of the M. desuturinus species-group. The latest studies of Merodon in Africa have revealed the existence of two new species within the taxon previously known as Merodon planifacies, found exclusively in the Drakensberg Mountains in Republic of South Africa, specifically in the Cathedral Peak National Park and the Royal Natal National Park. These two new species are M. capi in litt. and M. roni in litt. The current study presents the general description of the pre-imaginal stages of M. capi and M. roni, together with the functional morphology of the cephalopharyngeal skeleton. Geometric morphometry and linear measurements were carried out on the spiracular openings of the Posterior Respiratory Process (PRP) of pupae. There were differences in the shape of the PRP and spiracular openings between the two species. The feeding requirements of adults of the two species were analysed and compared with a third species from the M. desuturinus species-group, found in the same valleys at the same time: M. drakonis Vujić & adenković, 2018. Pollen grains found on the body and in the gut were identified and counted; the morphology of the mouthparts of the adults was also described and compared. ; This study was funded by the project of the European Union: Horizon 2020, Marie kłodowska-Curie action, Research and Innovation Staff Exchange (RISE) Programme: FlyHigh – Insect-plant relationships: insights into biodiversity and new applications.

We investigated the phylogeographic patterns of Merodon species (Diptera, Syrphidae) in the Eastern Mediterranean. Ten species were sampled on five different islands and mainland sites as a minimum. All samples were screened for their mtDNA COI barcode haplotype diversity, and for some samples, we additionally generated genomic fingerprints. The recently established zoogeographic distribution categories classify these species as having (1) Balkan distribution; (2) Anatolian distribution; (3) continental areas and large islands distribution; and (4) with wide distribution. The ancestral haplotypes and their geographical localities were estimated with statistical parsimony (TCS). TCS networks identified as the ancestral haplotype samples that originated from localities situated within the distributional category of the species in question. Strong geographical haplotype structuring was detected for many Merodon species. We were particularly interested to test the relative importance of current (Aegean Sea) and past Mid-Aegean Trench) barriers to dispersal for Merodon flies in the Aegean. We employed phylogenetic β-diversity (Pβtotal) and its partition in replacement (Pβrepl) and richness difference (Pβrich) to test the importance of each explanatory variable (interisland distance, MAT, and island area) in interisland differences using partial Mantel tests and hierarchical partitioning of variation. β-Analyses confirmed the importance of both current and past barriers to dispersal on the evolution of group. Current interisland distance was particularly important to explain the replacement of haplotypes, while the MAT was driving differences in richness of haplotypes, revealing the MAT as a strong past barrier whose effects are still visible today in the phylogenetic history of the clade in the Aegean. These results support the hypothesis of a highly restricted dispersal and gene flow among Merodon populations between islands since late Pleistocene. Additionally, patterns of phylogeographic structure deduced from haplotype connections and ISSR genome fingerprinting data revealed a few putative cases of human-mediated transfers of Merodon spp. ; This research has been co-financed by the European Union (European Social Fund – ESF) and Greek national funds through the Operational Program "Education and Lifelong Learning" of the National Strategic Reference Framework (NSRF) – Research Funding Program: THALES. Investing in knowledge society through the European Social Fund," and Carl Cedercreutz Foundation, Helsinki, Finland.

Merodon capi Vujić et Radenković, 2020 and Merodon roni Radenković et Vujić, 2020 are two cryptic species belonging to the Merodon planifacies Bezzi, 1915 species complex that have recently been described, with the differences between them being revealed by molecular and geometric morphometry studies of adult specimens. In the present study, the preimaginal morphology of both species is described and displayed, with the material used corresponding to samples taken from bulbs of Merwilla plumbea (Lindl.) Speta plants at two locations in KwaZulu-Natal province (South Africa). The preimaginal stages were compared, looking for morphological evidence supporting species divergence. Linear and geometric morphometric analyses of the larval posterior respiratory process were conducted for the first time and the results of these analyses support the separation of the two taxa. Information about the life cycle and the relation with the host plant is also provided. In addition, we carried out a preliminary study of the adult feeding requirements of the species, based on the description of the mouthparts and an analysis of the pollen present in the gut and on the integument of adults. The results of the study supports a close relationship between the preimaginal stages and plant species of the Hyacinthaceae family. ; The study was mainly funded by the European Union project: Horizon 2020, Marie Skłodowska-Curie Actions, Research and Innovation Staff Exchange (RISE) Programme: FlyHigh – "Insect–plant relationships: insights into biodiversity and new applications" (project 645636). The study was partly supported by the Ministry of Education, Science and Technological Development, Republic of Serbia, Grant No. 451-03-68/2022–14/200125 and Grant No. 451-03-68/2022–14/200358. It was also supported by the research department of the University of Alicante in the framework of a predoctoral grant (UAFPU2019-03). This manuscript was written as a part of a PhD project conducted by Andrea Aracil at the University of Alicante (Spain).