National Repository of Grey Literature 43 records found  beginprevious21 - 30nextend  jump to record: Search took 0.01 seconds. 
Causes of bee loss (Anthophila) in the landscape
Bureš, Vít ; Straka, Jakub (advisor) ; Tropek, Robert (referee)
Bees (Anthophila) are one of the most important pollinators in the majority of Earth's biotopes. They interact with almost one-fifth of flowering plants and together with other pollinators they secure one- third of human food sources. Since the end of World war II,along-term decrease in numbers of bees and other insects is observed due to degradation of natural habitats, expansion of agriculture, pesticide usage, parasites, and infections. In North America and Europe, several studies reported a significant loss of bee diversity and abundance. The situation in tropics is unclear and there is not enough evidence if bees are threatened there. Specific changes in relation to the decrease of the bee population are observed in the case of honey bee (Apis mellifera). Due to human beekeeping activities and specific honey bee attributes such as bigger body size or tolerance to lower temperature, honey bees show different trends in their abundance than other bees. This study discusses the causes of these losses and possible future consequences, for example, the collapse of ecosystems as a result of pollination crisis or lack of human food. On the other hand, several phenomena such as extensive agriculture, green cities, or wildfires have a positive impact on bee abundance and diversity. This thesis presents...
Evolution of sociality and parental care in bees of the genus Ceratina
Mikát, Michael ; Straka, Jakub (advisor) ; Schwarz, Michael (referee) ; Bogusch, Petr (referee)
Small carpenter bees (genus Ceratina) are an excellent model taxon for the study of evolution of parental care and origin of eusociality. Prolonged offspring care is typical for this bee genus. Females usually guard their offspring until adulthood and later feed their adult offspring pollen and nectar. Moreover, most of studied species are facultatively eusocial, a trait probably inherited from the common ancestor of the genus. Although Ceratina bees have generally very interesting behavior, detailed studies were performed in only a few species, usually from North America, Japan and Australia. Only anecdotal observations of natural history existed for a few European species, and detailed research has not been performed before my thesis. The goal of my thesis is to explore the natural history of European species of Ceratina and to identify possible costs and benefits of this species' behavioral traits. I focused on following these behavioral traits: social nesting, guarding of offspring until adulthood, and feeding of mature offspring. Through my master project, I discovered biparental care in species C. nigrolabiata, therefore the most important goal of my Ph.D. project is the evaluation of costs and benefits of this behavior. Guarding of offspring by mother significantly influences their survival,...
Význam včelařství a podmínky pro jeho rozvoj v regionu
Janštová, Ivana
The bachelor thesis is devoted to beekeping and its conditions for development in Vysočina region. The first part defines the meaning of beekeping in regional development and beekeeping like a form of small business. There is basic information for upcoming beekepers inluding the possible obstacles or forms of financial support. The practical part is focused on analysis of the Vysočina region and its suitability of beekeeping development. In this part is model study of estimated initial investment and profit for beginning beekeepers. The final part of thesis includes controlled interview with the chairman of Czech Beekepers Association in Velká Bíteš. The aim of this interview is to find out the current situation of beekeeping in the region from a perspective of a beekeeper. Afterward the shortcomings are defined with suggested possible solutions for improving the situation in the region.
Simulation and Management System for Beekeepers
Kaňovský, Zdeněk ; Kočí, Radek (referee) ; Peringer, Petr (advisor)
This bachelor thesis deals with analysis, design and implementation of the management and simulation system for beekeepers. The management system provides storing, updating and browsing the state of bee hives and is designed for the type of hives with removable frames. The simulation system contains the model of collecting nectar by honey bees and is addapted to management system. Depending on parameters of simulation model the application visualizes locations where would honey bees probably fly for the nectar and shows the amount of collected honey in one day.
Population genetics of bees
Beranová, Tereza ; Straka, Jakub (advisor) ; Munclinger, Pavel (referee)
Bees are one of the most important group of all insect, which plays a significant role in crop pollination. This bachelor thesis is review of articles, which speaks about genetic diversity of Apidae (Apoidea, Anthophila) and factors, which influence genetic diversity of this family. This thesis represents anthhropogenic impact, such as urbanization and fragmentation, and impact, which was not caused by human population, such as, climate change and parasite impact, on bee population. Part of this thesis is created by bee life overview and basic information about population genetics. The aim of this work is finding extent of declining pollinator problem, especially wild bees and also naming the bacic methods, which are used in this work. Key words: population, DNA analysis, threats, conservation genetics, bees, biogeography
A new approach for assessing the suspected pesticide poisonings of honeybees: certified methodology
Erban, Tomáš ; Kamler, Martin ; Kadlíková, Klára ; Markovič, Martin ; Titěra, Dalibor ; Seifrtová, Marcela ; Halešová, Taťána
Honeybee colonies are exposed to hundreds of plant protection products, which are especially due to improper use possible source of honeybee poisoning. The methodology introduces to the issue of honeybee poisoning including legislation and contributes with novel aspects to the indication and evaluation of the suspected honeybee poisonings, which are anually investigated by the State Veterinary Administration and the Central Institute for Supervising and Testing in Agriculture in Czechia. The methodology provides instructions to identify honeybee posining and notification of that finding. Moreover, possible confusions of the poisonings with honeybee diseases are highlighted. Some sections of the methodology provide innovative recommendations for improvement of honeybee poisoning assessing including determination of the extent of colony contamination. The present methodology is useful for the state administration, beekeepers, scientific and educational purposes.
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Population genetics and speciation in Stylops (Strepsiptera)
Kodejš, Karel ; Straka, Jakub (advisor) ; Černá, Kateřina (referee)
This thesis is focused to population genetics of selected species of genus Stylops in Europe. Within this genus, five species was analysed by usage of two approaches - microsatellite analysis in Stylops ater and analysis of mitochondrial DNA in all five species. Mitochondrial gene for cytochome c oxidase (1st subunit) was used. For microsatellite analysis was performed bayesian clustering analysis and ABC approach (Aproximate Bayesian Computation). Mitochondrial markers were processed by making haplotype networks and demography analysis by computing Bayesian skyline plots. For Stylops ater, surprisingly low lewel of population subdivision was detected, yet with clearly differentiated population clusters from Scandinavia and baltic coast of Europe, which may imply period of isolation of these populations or relativelly recent population expansion and genetic differentiation due to lower population sizes. Next, hypotesis of possible temporal segregation of subpopulations of Stylops nevinsoni based on different aktivity period of their host species groups, was supported. In other three species, population subdivision was observed to be related either due to host specialisation (Stylops mellitae) or geographic consequences (S.nassonowi, S.spreta). Interesting finding is also detection of population...
Social monogamy and parental care in bees of the genus Ceratina
Mikát, Michael ; Straka, Jakub (advisor) ; Bryja, Josef (referee)
Parental care is one of the most successful strategies for providing offspring survival. There are differences in type of care between taxa. There are biparental care, maternal care, paternal care and alloparental care. Bees of the genus Ceratina are suitable model taxon for study of parental care evolution. There is a long time known maternal care and eusociality, in this genus. A species of the genus Ceratina, which has biparental care, is introduced in this thesis. Field experiments were performed from 2011 to 2013 in Podyjí National Park, especially in locality Havraníky heath. Four model species, which are occurring in the Czech Republic, were selected: C. chalybea, C. cucurbitina, C. cyanea and C. nigrolabiata. Artificial nesting opportunities were installed to the field site. Relationship between individuals in nests of C. nigrolabiata was examined by newly developed microsatellite loci. All studied species are solitary in nesting behavior. Their nest structure and nesting phenology is described. Guarding of full brood nest to adulthood of offspring is characteristic behavioral trait for Ceratina bees. This guarding is essential for offspring survival. Experimental nests with removed mother often failed by ant predation, parasitation by chalcid wasp and nest usurpation by other individuals of the...

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