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Parasitic wasps Anaphes flavipes Förster, 1841 (Hymenoptera: Mymaridae) as model for parasitoid-host interactions study
Samková, Alena ; Janšta, Petr (advisor) ; Honěk, Alois (referee) ; Hrček, Jan (referee)
Parasitic wasps have a wide range of specific developmental interactions with their hosts due to a close "parasitoid-host" relationship and that allows the study of many ecological and evolutionary questions. In our work, we focused on the parasitoid-host interactions in the parasitic wasp Anaphes flavipes (Förster, 1841) (Hymenoptera: Mymaridae). Because A. flavipes show a high variability of morphology and size, they have been repeatedly described as a new species in the past. Thus, we first redescribed the species and we compared the variability of some morphological structures for wasps from different localities (Paper 1). The high variability of the body size of wasps is reviewed in the second article, where we propose that females of A. flavipes do not decide according to the generally known "trade-off" scheme, if they will have more smaller offspring or fewer bigger offspring. In fact, the number of offspring depends on the body size of the female ("body size-fitness" hypothesis), which determines the variable reproductive strategies of mothers (the number of individuals that are laid into one host by a single female) (Paper 2). The third manuscript deals with the reproductive strategy of gregarious parasitoids. The reproductive strategy does not have to be stable; in the case of A....
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Biology and taxonomy of Anaphes flavipes (Hymenoptera: Mymaridae) and potential use for biological control
Samková, Alena ; Janšta, Petr (advisor) ; Holý, Kamil (referee)
My master thesis deals with biology and morphology of the species Anaphes flavipes (Chalcidoidea: Mymaridae) and its potential use for biological control of leaf beetles. Particularly, the fitness of wasps was studied and a statistically significant difference in number of parasitize host eggs for mated females compared to non-mated. The effect of feeding parental population on the number of parasitized host eggs, the number of offspring in F1 generation or their sex ratio, was not proved. Study of host specificity of A. flavipes indicates preference for host eggs of species Oulema melanopus. Preference for heavier host eggs was not confirmed. The effect of host eggs weight on number of eggs wasps inside was not conclusive either. Length of parasitism of host eggs was consistent with earlier studies. The passive defense of host O. gallaecina against parasitoid was observed. Variability of the species depending on location, host, nutrition, etc. was determined using morphological measurements. The third part of the thesis is focused on population density of A. flavipes and its hosts in the localities of organic versus conventional farming in order to use the parasitoid for biological control. There was no significant difference in the size of pest and parasitoid populations between the types of agriculture....
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Termination of employment - psychological and social aspects
Samková, Alena ; Reichel, Jiří (referee) ; Šnýdrová, Ivana (advisor)
This bachelor work is focused on subject of the employment termination, incurred consequences and possible relief and professional help to manage this situation. Psychological and social aspects are especially pointed out. There are mentioned other categories as well as the aspects which are concerned by the unemployment problematics. Unemployment aspects are defined in the context of the job importance and its place in a human life. I am also trying to specify the concept of personality, work motivation and career as the key aspects of the employment itself. Further I am trying to answer the question, how all these elements influence quitting a job and incurred unemployment and helping to manage this complicated situation for unemployed people. I am resuming possible reasons for the employment termination in two lines, the reasons for an employee as well as for an employer. I am further considering the subject of the unemployment, the specifics and other aspects which are related to the job termination. The consequence and the aspects when quitting job are completed with the methods how to deal with this complicated situation. Finally I am mentioning the possibilities of relief and professional help, which are accessible to the unemployed people, in order to overcome critical situation caused by quitting a...
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