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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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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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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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Speciation of the genus Lethrus (Coleoptera: Geotrupidae) of the eastern mediterranean
Drožová, Dana ; Janšta, Petr (advisor) ; Bezděk, Aleš (referee)
Earth-boring dung beetles of the genus Lethrus Scopoli, 1777 belong to the family Geotrupidae, classified into three subfamilies (Geotrupinae, Lethrinae a Taurocerastinae). The description of about 120 species, divided into nine subgenera, is based on morphology and geographic distribution. Shape of mandibles, ventral mandible processes, pronotum and structure of external male genitalia are used as diagnostic morphological characters for taxa. The richest species diversity is known from Central Asia. The distribution area reaches, in the east, up to Mongolia and China, and in the west, up to Southeast Europe. All species are robust, relatively large flightless beetles with low dispersial ability. They feed on parts of fresh plants instead of feces like other dung beetles. Master thesis is focused on the species distributed in the Eastern Mediterranean and Central Europe. This area is inhabited only by nominotypical subgenus Lethrus. The main goal of thesis is to clear up phylogenetic relationships between species of subgenus and speciation events using molecular genetic methods. We have examined 91 samples of the genus Lethrus using two mitochondrial genes - cytochrome b (382 bp, 80 sequences), cytochrome oxidase I (815 bp, 87 sequences) and nuclear gene 28S rDNA (D2-D5) (1100 bp, 11 sequences)....
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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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Phylogeography of the praying mantis (Mantis religiosa) in central Europe
Urbánková, Hana ; Janšta, Petr (advisor) ; Kočárek, Petr (referee)
The praying mantis (Mantis religiosa) is the only representative of the order Mantodea in central Europe. Within Czech Republic, this species is distributed mostly on xerothermic localities in southern Moravia. However, M. religiosa has been spreading more to the north not only in Czech Republic, but also in other Europian countries recently. The aim of this study was to reconstruct phylogeography based on genetic markers. It seems that studied species was distributed at least in three lineages in Europe, which could be connected with glacial refugias. First lineage was spread to the north probably from Pyrenean peninsula, second lineage from Crimea peninsula and third lineage from Balkan area. Nine microsatellite loci were tested and will be used for consequent sctudy of phylogeography and distribution of M. religiosa within Europe. Keywords: Mantis religiosa, mtDNA, microsatellite, expansion, phylogeography, phylogeny.
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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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