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Food and host specialization in Aculeata (Hymenoptera)
Hochová, Veronika ; Policarová, Jana (advisor) ; Černá, Kateřina (referee)
Aculeata is a group of insects, its representatives vary significantly in the use of resources which are necessary for its survival and reproduction. Herbivores which live on parts of plants, carnivores which hunt other insects and omnivores are included in this group. There are also parasitic species such as cleptoparazites, brood parasites or parasitoids classified in Aculeata. Particular groups of Aculeata are adapted to resourcing, these adaptations exist in adult and immature stages simultaneously. Adaptation to the kind of source can lead to adjustment of mouthpart for easier prey hunting or nectar collecting, corbicula and special hair intended for collecting pollen or oils, a sting used for incapacitate the host or a sting for defense. Aculeata varies to such an extent how they are specialized in food and the host. Aculeata incorporates closely specialized species together with generalized species. The known information about the specialization Aculeata on food and host is summarized in this thesis.
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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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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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Importance of insect for the pollination of crops
RŮŽIČKA, Vít
The pollination is an essential service of the ecosystem, which involves besides natural influences also animals. Hymenopteran insects belong to the most significant pollinators. For humans, the most important pollinator is the honey bee (Apis mellifera), which is bred for thousands of years, but its state is being declined in last decades. Reasons of the decline of bee colonies can be found in the intensification of agriculture (pesticides, herbicides and other chemicals) and spreading of diseases (American foulbrood and varroasis). Another important pollinator, which could possibly replace honey bees, are solitary wild bee species. But even those are also affected by intensive agriculture. In these species it is not affected only by the massive use of chemical agents, but also by the change in the structure of the landscape and the loss of natural location for nesting. An important step to protect bees (honey bees and wild bees) is the quantification of its value in the ecosystem service. On this basis, the governments compile new laws, but it is also important for protecting at the regional level.
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Diversity of bees (Hymenoptera: Apiformes) in oilseed rape field
VYSKOČILOVÁ, Pavlína
Measuring the diversity of bees was provided in two rapeseed fields (Dešenice, Miletice) in western Bohemia, where various species of bees were caught at eight different locations during two periods (March - April, May June). The bees were collected by using Moerickeho cups (yellow traps) with a concentrated solution of water and detergent.
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Population biology of \kur{Rhytidoponera} ants (Hymenoptera:Formicidae)
BIZOS, Jiří
Ants from the genus Rhytidoponera are known for specific type of social organization in which some workers can reproduce. Species of this ants are commonly occuring in lowland rainforests of New Guinea but their biology is unknown to great extent. This thesis reviews available molecular methods suitable for study of population structure and phylogeography of Rhytidpoponera ants in rainforest environment.
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