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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,...
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The effect of experience and floral traits on preferences and flower constancy in Eristalis tenax
Haveldová, Alice ; Janovský, Zdeněk (advisor) ; Mikát, Michael (referee)
Intraspecific pollen transfer is crucial for ensuring successful pollination and subsequent reproduction of many plant species. Mechanisms directly influenced by plants, that can increase the proportion of intraspecific pollen through their flower form (individual floral traits) are preferences and constancy of pollinators. The proportion of intraspecific pollen transfer increases with higher preferences or constancy of the pollinator. Pollinator preferences and constancy tend to change over its lifetime based on experience with the flowers they have visited. Very few studies have examined the effect of experience on preferences and especially constancy in relation to multiple floral traits in hoverflies (Syrphidae, Diptera), which are an important pollinator group. In this study, I investigated the degree of preference and constancy of common drone fly Eristalis tenax L (Syrphidae) as a function of two floral traits, colour and size, and as a function of experience. I did so by monitoring visits and flights in arrays of artificial flowers. The hoverflies were of two origins: naïve (reared under laboratory conditions, with no previous experience of visiting flowers) and experienced (captured in the wild with previous experience). Naïve individuals made decisions primarily based on colour, with size...
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Pollination in urban ecosystems
Krygielová, Anna ; Janovský, Zdeněk (advisor) ; Mikát, Michael (referee)
Pollination success in the urban area mainly depends on the characteristics of plant populations and their pollinators, which are determined by the structure and characteristics of the urban ecosystem. Urbanization is a complex and uneven integration of landscape attributes such as habitat fragmentation, a high proportion of built-up area, the often limited size of green areas, and lower connectivity between them. These particular predictors have different effects on plant and pollinator abundance and species diversity. In general, an increasing level of urbanisation reduces the quantity and quality of pollination and therefore negatively affects the reproductive success of plants. On the other hand, in comparison with intensive agricultural landscapes urban areas (especially urban fringes and semi-natural urban areas) can contribute to the diversity, abundance, and reproductive success of plants and the diversity and abundance of their pollinators. This potentially positive influence of the city on biodiversity can be further developed through effective urban planning and appropriate management of existing public and private green areas in the city. Keywords: pollination, urban ecosystems, urbanisation, urban characteristics, urban green spaces, plant-pollinator interactions, plant reproductive success
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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,...
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Pollinator pollen carryover effectiveness and plants' ability to enhance it
Freudenfeld, Martin ; Janovský, Zdeněk (advisor) ; Mikát, Michael (referee)
Pollinators carry over pollen from one flower to another. They facilitate plant reproduction. Pollinator functional groups differ in their effectiveness of pollen carryover. Quantity of pollen grains on their body and deposition on stigma are very important. Pollinator carryover capacity depends on its functional traits. Body size, hairiness, visitation behaviour, foraging preferences, flower constancy and abundance of pollinators are significant. Plants can enhance effectiveness of their pollination by adaptations to specific pollinator functional groups. They improve positioning of pollen on pollinators by specific changes to floral morphology, quantity and size of pollen grains. They can also enhance the effectiveness through aggregation of pollen grains into groups or into pollinia or by optimisation of pollen release in time.
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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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Cyclic development of social communities in insects
Mikát, Michael ; Straka, Jakub (advisor) ; Zrzavý, Jan (referee)
A lot of animal species forms societies - groups of regularly interacting individuals. Societies vary in social structure and relations among their members. Societies with reproductive division of labour are the most complex. Origin of reproductive division of labour is one of main themes of evolutionary biology. In this thesis classification of societies according actual composition is summarized and modified. Societies very changed during colony cycle in taxons which forms eusocial levels societies. For these taxons is describing of society cycle very valuable for comprehension of social strategy. In this thesis cycles of societies are classified and selection pressures which may change society cycle are summarized.
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