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Phylogeny of selected species groups of the genus Torymus (Hymenoptera: Torymidae)
Křížková, Barbora ; Janšta, Petr (advisor) ; Skuhrovec, Jiří (referee)
Chalcid wasps (Chalciodiodea) is superfamily within parasitic group of the order Hymenoptera. These insects attack other arthropods. My thesis is focused on phylogeny of selected species groups of the genus Torymus Dalman 1820, whose range of hosts includes mainly gall-forming insect as gall wasps (Hymenoptera: Cynipidae) and gall midges (Diptera: Cecidomyiidae). Using genes 28D2 rDNA, COI and CytB, I constructed phylogenetic trees, which helped with discussing current view on classification of the genus and with inferring new findings about co-evolution with host organisms. Previously established morphological - ecological species groups were not supported by my analyses in many cases. Morphological traits seem to be convergent for many species. They often do not support observed monophyla as apomorphies. On the other hand, ecology and natural habitat of species was common for many branches in my cladograms. It was found out, that recent hosts are not probably original hosts of the group. Adaptive radiation in different habitats is likely to be the phenomenon that stands behind present-day host range of Torymus species. This process could have occurred after swapping to gall midges and gall wasps. Key words: Chalcidoidea, Torymus, phylogeny, parasitoid, host specifity, co-evolution
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Phylogeny of selected species groups of the genus Torymus (Hymenoptera: Torymidae)
Křížková, Barbora
Chalcid wasps (Chalciodiodea) is superfamily within parasitic group of the order Hymenoptera. These insects attack other arthropods. My thesis is focused on phylogeny of selected species groups of the genus Torymus Dalman 1820, whose range of hosts includes mainly gall-forming insect as gall wasps (Hymenoptera: Cynipidae) and gall midges (Diptera: Cecidomyiidae). Using genes 28D2 rDNA, COI and CytB, I constructed phylogenetic trees, which helped with discussing current view on classification of the genus and with inferring new findings about co-evolution with host organisms. Previously established morphological - ecological species groups were not supported by my analyses in many cases. Morphological traits seem to be convergent for many species. They often do not support observed monophyla as apomorphies. On the other hand, ecology and natural habitat of species was common for many branches in my cladograms. It was found out, that recent hosts are not probably original hosts of the group. Adaptive radiation in different habitats is likely to be the phenomenon that stands behind present-day host range of Torymus species. This process could have occurred after swapping to gall midges and gall wasps. Key words: Chalcidoidea, Torymus, phylogeny, parasitoid, host specifity, co-evolution
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Phylogeny and evolution of the family Megastigmidae (Hymenoptera: Chalcidoidea)
Böhmová, Julie ; Janšta, Petr (advisor) ; Opatová, Věra (referee)
The family Megastigmidae (Hymenoptera: Chalcidoidea), one of the hymenopteran parasitoid families, is unique in containing many species with phytophagous larval feeding strategy. A number of species of different genera are seed-feeders and the genus Bortesia is even capable of inducing galls. The family Megastigmidae is found mainly in the Australian region but a few genera/species groups are widespread throughout different areas, mainly in the Oriental and the Holarctic region. The main goal of this study was to map phylogenetic relationships among genera and clarify the following: the overall number of transitions between a parasitoid and a phytophagous way of life, the ancestral feeding strategy of the family, the evolution of feeding strategies in the genus Megastigmus, and the geographical area of origin of the family. The questions were tested based on a phylogeny reconstructed by a state-of-the-art method - sequencing of "Ultra-Conserved Elements (UCEs)" - using 100 specimens of Megastigmidae from 11 out of 12 currently valid genera selected taking into consideration their feeding strategy and biogeographical origin. The final dataset contains 1210 loci (570,000 base pairs in length) and most nodes are supported by bootstrap value 100. The results show that the family can be divided into 3...
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Adaptation of parasitoids used during host utilization in the Chalcidoidea superfamily (Hymenoptera)
Ročková, Lenka ; Janšta, Petr (advisor) ; Holý, Kamil (referee)
The Chalcidoidea superfamily is one of the most diverse groups of parasitic insects. The life strategy prevalent in most species of this superfamily is parasitoidism, which can be used by human as an effective tool in biological control. Parasitoids deal during their reproduction with the fact, that their hosts are often hidden in hardly accessible places. This matter of fact is probably the reason for development of some of the ovipositor's characteristics, that cannot be explained phylogeneticaly. These characteristics are therefore described as adaptations for parasitoid lifestyle. These adaptations mirror the nature of substrate which their hosts inhabitate and where the oviposition is being realised. Species inhabitating the same niche use to show different adaptations of the ovipositor, which could be explained by better distribution of the present resources. It is also considered a speciation factor of sympatric species. Detailed studies of the differences between ovipositor adaptations may simplify the determination procces of life strategies of hymenopteran insects, which could be performed based on ovipositor morphology. Key words: parasitic Hymenoptera, Chalcidoidea, ovipositor structure, hosts seeking, adaptation for host utilization, host discrimination
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Evolution of parasitic Hymenoptera hosts specialisation of the genus Torymus
Bubeníková, Kristýna ; Janšta, Petr (advisor) ; Bogusch, Petr (referee)
The genus Torymus (Chalcidoidea: Torymidae) has very diversified parasitic strategies and adaptations to its hosts. Its larvae are ectoparasitoids and attack mostly larvae of various gall wasps (Hymenoptera: Cynipidae) and gall midges (Diptera: Cecidomyiidae). However, few species prefer also other insect groups as a host or are even phytophagous. Many hypotheses concerning evolution of insect host associations were published, but have not been satisfactorily tested using parasitic insects as a model. In this thesis I studied coevolution of the genus Torymus and its hosts. The main questions are what kind of host shifts occurred during the evolution of host strategies and whether sister species of parasitoids are specific to the related hosts/or nonrelated hosts living in the same type of habitat. I also studied changes at morphological adaptations to its hosts. To test critically these hypotheses, I constructed phylogenetic tree of selected Torymus species based on 5 genes and compared their host association within and between clades of Torymus. Key words: Torymus, Chalcidoide, parasitoid, phylogeny, host specialisation
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Phylogeny of selected species groups of the genus Torymus (Hymenoptera: Torymidae)
Křížková, Barbora
Chalcid wasps (Chalciodiodea) is superfamily within parasitic group of the order Hymenoptera. These insects attack other arthropods. My thesis is focused on phylogeny of selected species groups of the genus Torymus Dalman 1820, whose range of hosts includes mainly gall-forming insect as gall wasps (Hymenoptera: Cynipidae) and gall midges (Diptera: Cecidomyiidae). Using genes 28D2 rDNA, COI and CytB, I constructed phylogenetic trees, which helped with discussing current view on classification of the genus and with inferring new findings about co-evolution with host organisms. Previously established morphological - ecological species groups were not supported by my analyses in many cases. Morphological traits seem to be convergent for many species. They often do not support observed monophyla as apomorphies. On the other hand, ecology and natural habitat of species was common for many branches in my cladograms. It was found out, that recent hosts are not probably original hosts of the group. Adaptive radiation in different habitats is likely to be the phenomenon that stands behind present-day host range of Torymus species. This process could have occurred after swapping to gall midges and gall wasps. Key words: Chalcidoidea, Torymus, phylogeny, parasitoid, host specifity, co-evolution
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Biology and taxonomy of Anaphes flavipes (Hymenoptera: Mymaridae) and potential use for biological control
Samková, Alena ; Janšta, Petr (advisor) ; Holý, Kamil (referee)
My master thesis deals with biology and morphology of the species Anaphes flavipes (Chalcidoidea: Mymaridae) and its potential use for biological control of leaf beetles. Particularly, the fitness of wasps was studied and a statistically significant difference in number of parasitize host eggs for mated females compared to non-mated. The effect of feeding parental population on the number of parasitized host eggs, the number of offspring in F1 generation or their sex ratio, was not proved. Study of host specificity of A. flavipes indicates preference for host eggs of species Oulema melanopus. Preference for heavier host eggs was not confirmed. The effect of host eggs weight on number of eggs wasps inside was not conclusive either. Length of parasitism of host eggs was consistent with earlier studies. The passive defense of host O. gallaecina against parasitoid was observed. Variability of the species depending on location, host, nutrition, etc. was determined using morphological measurements. The third part of the thesis is focused on population density of A. flavipes and its hosts in the localities of organic versus conventional farming in order to use the parasitoid for biological control. There was no significant difference in the size of pest and parasitoid populations between the types of agriculture....
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Phylogeny of selected species groups of the genus Torymus (Hymenoptera: Torymidae)
Křížková, Barbora ; Janšta, Petr (advisor) ; Skuhrovec, Jiří (referee)
Chalcid wasps (Chalciodiodea) is superfamily within parasitic group of the order Hymenoptera. These insects attack other arthropods. My thesis is focused on phylogeny of selected species groups of the genus Torymus Dalman 1820, whose range of hosts includes mainly gall-forming insect as gall wasps (Hymenoptera: Cynipidae) and gall midges (Diptera: Cecidomyiidae). Using genes 28D2 rDNA, COI and CytB, I constructed phylogenetic trees, which helped with discussing current view on classification of the genus and with inferring new findings about co-evolution with host organisms. Previously established morphological - ecological species groups were not supported by my analyses in many cases. Morphological traits seem to be convergent for many species. They often do not support observed monophyla as apomorphies. On the other hand, ecology and natural habitat of species was common for many branches in my cladograms. It was found out, that recent hosts are not probably original hosts of the group. Adaptive radiation in different habitats is likely to be the phenomenon that stands behind present-day host range of Torymus species. This process could have occurred after swapping to gall midges and gall wasps. Key words: Chalcidoidea, Torymus, phylogeny, parasitoid, host specifity, co-evolution
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