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Design and functional morphology of insect wings
Jechová, Kateřina ; Prokop, Jakub (advisor) ; Janšta, Petr (referee)
Animal fly ability is undoubtedly one of the biggest innovation in evolution that allow animals to settle down another space on the Earth - the air. However, there are significant impacts on the other organisms during the evolution, too. The insect is single group of invertebrates with abilities to fly and because of that it became the most diversified group of organisms. There are a couple of theories about origin of the insect wings. Two major hypotheses considering the recent insects with their fossil record are widely known. Nevertheless, there is no direct clue to the first Pterygota due to the discontinuity of fossil record in the initial phase of their evolution The wing is very complex and unique structure throughout organisms. Insects became very good fliers during the evolution and wings are also used to protect of the body, carrying sensory organs, etc. Nevertheless, only very few insect species are well explored in term of flight and, an open theme for future studies. Aim of the present work is to describe the significance of the wing and to briefly review its morphological and design properties. Key words: Insecta, Pterygota, wing, venation, morphology, flight, evolution.
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Biology of gall wasps (Diplolepis spp.) (Hymenoptera: Cynipidae) in palearctic region
Vitáček, Jakub ; Janšta, Petr (advisor) ; Holý, Kamil (referee)
This bachelor thesis is focussed on description of biology of gall wasps from the genus Diplolepis spp. (Hymenoptera: Cynipidae) in the palearctic region with the emphasis on some interesting phenomenons in their life cycle. These wasps induce galls obligatory on roses (Rosa spp.) and are widely distributed in the holarctic region. Many authors focussed on research of parasitoids, which use wasps larvae as food source. It was also recognized that inquilines lost their ability to induce own galls. However, their development is still dependent on galls tissues, because they feed on cells within galls. Rose gall wasps reproduce mostly without any mating. Female lay unfertilized eggs and males are very rare. Recently, development of modern techniques enable authors to study infection by bacteria of the genus Wolbachia and its role in the wasps parthenogenetic development. It is also apparent difference between the levels of our knowledge about individual species in this bachelor thesis. We have relative rich knowledges about European rose gall wasps, on the other hand biology of some Asian species is still very poor.
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Flow cytometry and its use for study of insects
Stuchlíková, Magdalena ; Janšta, Petr (advisor) ; Sadílek, David (referee)
Flow cytometry is a modern technique in research, playing a significant role in biomedicine and botanics. Despite its benefits (speed, simplicity, low costs), flow cytometry is currently not used in the study of insects on a large scale. This thesis gives an overview as to how flow cytometry is used in research on insects and summarises the results of such study. This pertains to genome size and its connections to other phenomena. Other focal points of research, such as ploidy and base pair ratios, are addressed to a lesser extent. Key words: flow cytometry, use in study of insects, genome size, ploidy, invertebrates
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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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Ecology of pollination networks
Hadrava, Jiří ; Janšta, Petr (advisor) ; Novotný, Vojtěch (referee)
In communities, plants and pollinators are organized into complex network of relations. Description of structure in this network can contribute to understanding of community dynamics and persistence of biodiversity. Better understanding of patterns in assemblages of plants and pollinators may also help in their protection. The aim of this work is to review recent methodological principles in the pollination network analyses and to show potential problems in concept of ecological networks. Graph theory is breefly summarized and applied to the description of pollination networks. As an example, results on comparison of communities from different geographical sites are given.
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Hymenopteran parasitoids (Hymenoptera: "Parasitica") and their impact on hosts species behaviour
Stiblík, Petr ; Janšta, Petr (advisor) ; Bogusch, Petr (referee)
Recently, many scientists have been focused on parasite or parasitoid host's manipulation. They don't describe only the changes in host behavior, but they even search for physiological background. Lots of papers dealing with hymenopteran parasitoids (Hymenoptera: Parasitica) host's manipulation have been published. The most studied are strongly adapted and host specific parasitoids, koinobionts. They developed very sophisticated mechanisms to manipulate their hosts for their own benefit. These parasitic wasps are not only very diverse group of the insect, but they even developed various ways to manipulate the hosts and their physiology. Sometimes the parasitoids use their hosts like a "food's vehicle", sometimes they manipulate just rates of some metabolites or suppress host's immune reaction. If the wasp's life-cycle is successful, the host does not develope to the adult's stage and is often consumed by the parasitoid larve.
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Phylogeny of parasitic wasps of Torymidae (Hymenoptera: Chalcidoidea) and evolution of their life-strategies
Janšta, Petr ; Vilímová, Jitka (advisor) ; Bryja, Josef (referee) ; Melika, George (referee)
The thesis is focused on phylogeny of the family Torymidae (Hymenoptera: Chalcidoidea) and evolution of their life-strategies. The study consists of general introduction to the phylogeny and classification of the family Torymidae chapter, four published papers in international journals and one manuscript prepared for submission. Firstly, our aim was to figure out the phylogenetic position of Torymidae as well as the position of other chalcidoid families inside superfamily Chalcidoidea (paper I and II). The supermatrix of sequencies of two ribosomal genes (18S rDNA and 28S rDNA) were developed for 649 species of chalcidoid taxa. However, family Torymidae was considered as polyphyletic group with the subfamily Megastigminae unrelated to the subfamily Toryminae (paper I). Monophyly of Torymidae was corroborated in another study (paper II) focused on molecular and morphological characters. We used a web-based, systematics workbench mx database for scoring 233 characters of 300 members of all chalcidoid families. Contrary to our previous only DNA-based study, we revealed also potential sister relationships of Torymidae with Ormyridae+Colotrechninae or Cerocephalinae+Diparinae respectively. Other paper (paper V) was focused on detailed study of Torymidae phylogeny. A total of 5 genes (18S rDNA, 28S rDNA,...
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