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Phytophagy as an alternative feeding strategy of parasitic Hymenoptera larvae
Böhmová, Julie ; Janšta, Petr (advisor) ; Skuhrovec, Jiří (referee)
Parasitoidism is considered to be the primary larval feeding strategy of parasitic Hymenoptera (Hymenoptera: Apocrita: Parasitoida). However, many species became secondarily phytophagous, in particular some species of Ichneumonoidea, Cynipoidea and Chalcidoidea. The bachelor thesis summarizes the knowledge about phytophagy in these superfamilies and divides them into four categories. The thesis further evaluates morphological and behavioural adaptations related to this way of life as well as other aspects of their coevolution with host plants.
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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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Spatial Variability in Pollination Networks
Hadrava, Jiří ; Janšta, Petr (advisor) ; Keil, Petr (referee)
Plant-pollinator interaction assembly can be represented as so called pollination network. Using these networks, assembly of plant-pollinator communities and geographic patterns in pollination networks can be studied. During last years, a great progress in describing patterns in structure of plant-pollinator interaction webs and in describing their spatial variability was made. However, these results are mostly based on data from previous studies, which are not seamlessly comparable due to their nonuniformity. My thesis aims at the methodological concepts of study on pollination networks. Based on meta- analysis of previously published data and on data from four years detailed study of plant-pollination system from one locality, I show several methodological problems caused by dissimilarities in sam- pling method of current pollination-network data. These dissimilarities could be responsible for some observed patterns in the assembly of pollination networks. Thus, I propose a uniform method for observing pollination networks suitable for macroecolo- gical meta-analyses (pollination network samples). I tested this method in the field and I described 49 pollination networks from the central and eastern Europe by using such method. In these ne- tworks, no nonrandom structure character such as...
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Spreading of praying mantis (Mantis religiosa) in Europe
Vitáček, Jakub ; Janšta, Petr (advisor) ; Gvoždík, Václav (referee)
Climate change is one of the most important factor determining species ranges. In Europe there is now evidence for northward areal expansion in many Mediterranean insects including the praying mantis (Mantis religiosa). This species is the only representative of the order Mantodea inhabiting central Europe. The northern edge of the species distribution currently reaches latitude 53ř North. Although, the praying mantis is well known insect there is not enough evidence about its phylogeography. In this work three mitochondrial genes (COI, COII, Cyt b) were selected for phylogenetic study. Results indicate three statistically supported distinct lineages in Europe: Eastern European, Central European and Western European. Presumably these lineages are consistent with isolation during the last glacial and re-colonization from glacial refugia. Reduced haplotype diversity on the northern edge suggests currently established populations at the northern distribution border. To validate mtDNA results it was also considered four microsatellite loci. Due to different type of inheritance mtDNA and nuclear DNA it is possible to compare two independent genetic datasets. Microsatellite analysis confirmed results obtained on mitochondrial data. Three major genetic clusters were found: east, west and central. Spatial...
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Parasitoid hymenoptera hosts specialisation and defensive mechanisms of their host species
Bubeníková, Kristýna ; Janšta, Petr (advisor) ; Holý, Kamil (referee)
Parasitoids (Hymonoptera: "Parasitica") are very large group of insects. Their diversity is also enormous in various morphological adaptations and hosts specialisations. The bachelor thesis summarize particular types of host specialisations and compare generalits and specialists from taxonomical, ecological, evolutionary and geographical point of view. The thesis include summary of theories concerning host-defence adaptations against parasitoids (i.e. morphological adaptations, space-time adaptations) as well. Key words: Apocrita, specialist, generalist, defensive mechanism, evolutuion
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Tribe Microdontomerini (Hymenoptera: Chalcidoidea: Torymidae) - phylogeny and evolution
Stiblík, Petr ; Janšta, Petr (advisor) ; Bogusch, Petr (referee)
Superfamily Chalcidoidea (chalcid wasps) represent the most species-rich group of the Hymenoptera and includes 22 families. Family Torymidae is one of those families and it's monophyly is currently intensively discussed. This particular thesis aims at the tribe Microdontomerini (Torimidae: Toryminae). Species of this tribe are usually minute inconspicuous wasps (body length ranges from 2 to 4 mm). Recent progress in phylogenetics of chalcid wasps allowes us to formulate robust hypothesis of Microdontomerini evolution, as a component of broader study of Chalcidoidea phylogeny and classification. My approach combines molecular and morphological evidence to formulate the most plausible evolutionary scenario. Dataset of 35 mostly morphological characters for 33 taxa including all existing Microdontomerini genera and 10 outgroups has been scored. Almost all characters has been studied and documented using Hitachi S-3700N-VP scanning electron microscope. In 117 taxa, 5 nuclear genes segments (18S, 28SD2, 28SD3-5, EF1alfa, Wingless) and 3 mitochondrial genes segments (COI-LCOHCO, COI-JerryPat, CytB) were sequenced, to get together the final molecular dataset of 387 Kbp. Molecular trees were built using maximum likelihood and Mr.Bayes algorithms. Evolution of morphological characters were mapped on the...
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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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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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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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