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Plasticity of circadian rhythms of the common bed bug
Čejková, Lada ; Balvín, Ondřej (advisor) ; Doležel, David (referee)
Circadian rhythms can be found in all organisms from prokaryotes through plants to animals. They are very plastic, able to adapt to the climatic conditions of the environment and the current availability of food, such differences in conditions led to origin of intraspecific polymorphisms of circadian rhythms. This bachelor thesis summarizes the known data on the circadian rhythm plasticity, managing mechanisms of circadian rhythms and their interdependence. Circadian rhythms were studied only sporadically in the human ectoparasite a bed bug (Cimex lectularius), rhythm reversal can be achieved just by changing the illumination. With knowledge about plasticity of circadian rhythms it shall be possible to identify the changes in the managing mechanisms of circadian rhythms in the bed bug. Key words: circadian rhythms, bed bug, plasticity of circadian rhythm, polymorphism of circadian rhythms
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Phylogeography and ecology of the Cimex species (Heteroptera: Cimicidae) in Europe; the evolution of taxa and specialization of hosts
Balvín, Ondřej ; Vilímová, Jitka (advisor) ; Hypša, Václav (referee) ; Votýpka, Jan (referee)
The life strategies of parasites and evolutionary mechanisms forming their diversity are particularly various and become frequent objects of study. The Ph.D. thesis deals with one of the obligate ectoparasitic haematophagous groups of insects, the species of the genus Cimex (Heteroptera: Cimicidae). Unlike in most other ectoparasites, the strategy of cimicids consists of remaining hidden in the shelter of their host. They use the host body only to feed and disperse. The advantage of the lower competition with other ectoparasites is counterbalanced by the need for particularly stable blood source, for which the cimicids choose social hosts living in colonies. The most frequent and the original hosts of cimicids are bats. The host range of particular species of Cimicidae is often rather broad. The morphological analysis of the Cimex pipistrelli species group showed, however, differentiation according to host bat species. This suggests a need for adaptation to particular host species within the usual range. The differentiation was not found reflected in the mitochondrial DNA. It is thus possible that cimicids can exhibit phenotype plasticity. The host associated morphological variability likely caused as many as three species of C. pipistrelli group to be described from Europe, from which two were...
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Differentiation of semiochemicals among lineages of the bed bug (Cimex lectularius)
Pilařová, Kateřina ; Balvín, Ondřej (advisor) ; Kateřina, Kateřina (referee)
Lineages of the common bedbug Cimex lectularius associated with bats and humans separated from each other tens or hundreds of thousands years ago. Currently, they are genetically isolated and some degree of postcopulatory reproduction barrier has been shown. This thesis aims to test the possible mechanisms of precopulatory isolation. Possible differences of semiochemicals between the host lineages were examined by experiments in arenas (four shelters, two unconditioned, one conditioned by scent of specific lineage and one by scent of non-specific lineage, put together in one arena, to which one bedbug male was introduced every time). For the experiment, six breeds (three from bat lineage and three from human lineage) which originated from different parts of Czech Republic were used.
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