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Functional Ultrastructure of Hymenopteran Stingers: Devastating Spear or Delicate Syringe
ČERNÝ, Jan
In this study, we tested the hypothesis that a micro-serrated edge on the honey bee Apis mellifera stinger tip serves as a tool for more intensive crushing of cell membranes in the victim's tissues. This could have mechanical consequences as well as initiate metabolic pathways linked to cell membrane breakdown (e.g., production of biogenic amines). Accordingly, we found that hymenopteran species that use their stingers as an offensive or defensive weapon to do as much damage to the victim's body as possible had this cuticular microstructure. In parasitic hymenopterans, on the other hand, this structure was missing, as stingers are solely used to delicately transport venom to the victim's body in order to do little mechanical harm. We also demonstrated that the stinger lancets of the honey bee A. mellifera are living organs with sensilla innervated by sensory neurons and containing other essential tissues, rather than mere cuticular structures.
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Factors affecting behaviour of avian predators to hoverflies (Syrphidae) and their models (Aculeata)
Truhlářová, Marie ; Exnerová, Alice (advisor) ; Sedláček, František (referee)
Batesian mimicry is an antipredator strategy used by harmless species to mimic dangerous models by their appearance. The so-called imperfect mimics are a phenomenon within Batesian mimicry. It would be expected that Batesian mimics are selected to resemble the model as perfectly as possible. However, in some species the resemblance is very poor. The aim of this study was to test reaction of predators towards a textbook example of Batesian mimics with imperfect mimicry, i.e., hoverflies (Syrphidae) and to verify some of the hypotheses describing imperfect mimicry. We conducted two experiments in which the model predators were great tits (Parus major). The topic of the first experiment was the effect of diversity of models on categorization and generalization of hoverflies. Birds were divided into two groups, with the first group receiving high diversity of models (10 species of Hymenoptera) and second group receiving low diversity of models (2 species of Hymenoptera). There were two parts of this experiment. Categorization training when great tits learn to discriminate between two categories of prey, palatable and unpalatable and generalization test, when great tits generalized their experience from categorization training to novel prey. Palatable prey was represented by non-mimetic flies (Diptera),...
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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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Preferences of the main groups of pollinators for the functional floral traits
Malá, Karolína ; Janovský, Zdeněk (advisor) ; Hadrava, Jiří (referee)
This bachelor thesis summarizes the preferences of the main functional groups of pollinators towards floral traits of plants. Due to coevolution and mutual selection pressures, these two life forms have begun to adapt to each other and develop traits on which the future of their life depends. The plant seeks to attract its pollinators, thus ensuring efficient pollen transfer or reproduction for its species. Attractants are used to motivate visitors to its flowers. These attractants provide pollinators with either direct rewards (food, shelter, brood) or rewards in the form of sensory perceptions (colour, scent, morphology). Recently, it has become apparent that flower colour, morphology and the type of food reward offered by the flower have the greatest influence on pollinator choice. Based on preferences towards attractants, we can organize several functional groups whose representatives have the same or similar choice preferences. Key words Pollination syndromes, pollinator, selection pressures, plant traits, coevolution, preferences, fidelity, diptera, coleoptera, lepidoptera, hymenoptera, birds, colour, morphology, rewards
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Parental care and sociality in family Halictidae (Anthophila)
Vinická, Eliška ; Straka, Jakub (advisor) ; Klimeš, Petr (referee)
Halictidae is an important family of bees interesting mainly for the diversification of social organisation of individual species. Their sociality ranges from solitary individuals who live and care for their offspring themselves, through species that build common nests, to eusocial colonies in which the reproductive division of labour has developed. Exploring such diversity among closely related species may contribute to understanding the evolution of sociality. Thus, we can observe the development of social organization up to its higher levels, such as eusociality, or conversely, gradual evolutionary regression to solitary individuals. For such research, however, it is necessary to know not only the phylogenetic development but especially a detailed description of social behaviour in individual species. However, there are few such studies. Some of them are summarized in this work.
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Genome Assembly and Annotation of Biparental Bee Ceratina nigrolabiata
Fraňková, Tereza ; Straka, Jakub (advisor) ; Kolísko, Martin (referee)
Biparental care in Hymenoptera is a little studied behaviour. This kind of parental care was discovered and the ethological aspect described in the bee Ceratina nigrolabiata from the Czech Republic and is well understood on the ethological level. However, biparental care is not a common behaviour and the lack of genomic studies of this behaviour complicates the understanding of the origin of the biparental care and its underlying pathways on the genomic and physiological level. This master's thesis presents the genome analyses of a biparental bee Ceratina nigrolabiata. It consists of a brief summary of the known parental behaviour across insects, characteristics of the genus Ceratina, summary of the used genomic methods and presents a candidate genes for the transcriptomic study of the biparental behaviour of Ceratina nigrolabiata. Key words: biparental care, genomics, Hymenoptera, Insecta, Ceratina, small carpenter bees
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Biosynthesis of the bumblebee male pheromones and its hormonal regulation.
Bártová, Adéla ; Valterová, Irena (advisor) ; Smrček, Stanislav (referee)
Bumblebees are important pollinators, commercially used in large-scale plant growing in greenhouses. Their males produce marking pheromones for mating, which attract young bumblebee queens. These pheromones are often a complicated mixture of chemicals, which is produced in the male labial gland, and the mixture itself is specific for each bumblebee species. The regulation of bumblebee sexual pheromone biosynthesis is largely unknown, and this Master's thesis is focused on the analysis of the mechanisms which lead to the regulation of the Bombus terrestris male pheromone's fat-acid and terpenes biosynthesis, specifically on stereospecific enzymatic reduction of double bond of farnesol. This thesis studies the influence of potential neurohormones on a specific enzymatic mixture, which is involved in the pheromone biosynthesis. Methods used in this project include biochemical, analytic and molecular-biology methods.
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Selected Meadow Pollinators and Their Didactical Use
Huňková, Helena ; Říhová, Dagmar (advisor) ; Hanel, Lubomír (referee)
This Master thesis is focused on selected pollinators of our meadows and their didactic integration into education. The thesis is divided into two parts - theoretical and practical. In theoretical part, there are defined two orders (Hymenoptera and Diptera), process of pollination, plants pollination strategies and pollen grain. Practical part is focused on research of dipterans (particularly on hoverflies) of which purpose was to find out which plants are most pollinated. Subsequent section deals with analysis of secondary school Biology textbooks in terms of representation of selected pollinators. Next section contains plan of practical exercise, which deals with whether honey contains pollen grains. In final section of practical part, a worksheet is presented, which verifies pupil's knowledge about pollinators. KEYWORDS Hymenoptera, Diptera, hoverfly research, pollinators, pollen, textbook analysis
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Signs of the Origin and Evolution of Eusociality in Hymenoptera on Genomic Level
Fraňková, Tereza ; Straka, Jakub (advisor) ; Musilová, Zuzana (referee)
Eusociality has evolved independently many times in social Hymenoptera and some of them are now at the brink of eusociality. Eusociality is a complicated set of genomic, ecological and behavioural traits closely interacting with each other. Recent studies presented many interesting outcomes which explain at least partially the possible connections to eusociality on the genomic level. However, the true origin and evolution of eusociality is yet to be refined. Because eusociality is such a dominant quality in the lives of eusocial Hymenoptera, it is important to clarify what causes eusociality to arrise. This thesis summarises the most prominent findings in the field of genomics and reviews not only the outcomes but also the issues of this problematics. The thesis deals with the classification of eusociality, brief introduction to the species lifestyles, which are of great importance for understanding the main part. The main part focuses on the concrete genomic data elucidating possible signs of the evolution of eusociality recognised so far. Key words: eusociality, genomics, evolution, Hymenoptera, Insecta
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