National Repository of Grey Literature 59 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Population Genetics of Parasites and Their Arthropod Hosts
Bezányiová, Kateřina ; Straka, Jakub (advisor) ; Votýpka, Jan (referee)
Arthropoda are currently the largest metazoan phylum. Given that organisms with parasitic lifestyle are thought to comprise the majority of existing species, it's easy to imagine an immense diversity of parasites interacts with arthropods. However, in comparison to organisms parasitising vertebrates, parasites of arthropods are direly understudied despite their abundance, importance, and potential usefulness. Amongst other things, parasites can be used as tools allowing the inference of information on host life history, ecology, and past events the host species have experienced. Population genetic structure of parasites and other symbionts may reflect these traits and events due to their close relationship with the host. Even though parasites comprise a diverse assemblage of taxa, it's possible to identify convergent patterns in their biology. Models predicting congruent population genetic co- structuring can be thus based on a few traits such as host specificity, life cycle complexity or parasite and/or host dispersal. In some cases, the parasite may provide better resolution of population structure than the host itself, serving as a proxy that may be used to direct conservation programmes of both the host and parasite, as has already been done with parasites of vertebrates. This thesis summarises known...
Nesting behaviour and alternative reproductive tactics in solitary bees (Hymenoptera: Apoidea)
Rezková, Kateřina ; Straka, Jakub (advisor) ; Konvička, Martin (referee)
Proposed thesis describes nesting behaviour of gregarious solitary bee species Andrena vaga. The knowledge of behaviour in solitary bees can be very important, because solitarity might represent the initial point in the evolution of eusociality and obligate cleptoparasitism. A population of the studied species was observed continuously for two nesting seasons, which enabled me to describe basic demographic characteristics of studied species such as lenght of bee season, longevity, density of population, number of nests per female life, etc. All the observed behavioural patterns were described in ethogram and their exact position in provisioning cycle was determined. This information helped me to compile average daily activity of studied species. I found out major differences in bee behaviour in both years and between nonparasitized and stylopized (parasitized by Stylops) bees. I proved the existence of intraspecific cleptoparasitism in form of usurpations. Because it is crucial to link female to the provisioned cell for the detection of intraspecific cuckoo-like behaviour, I tested two new methods of underground cell marking - protein marking and fluorescent dye marking. Powered by TCPDF (www.tcpdf.org)
Molecular identification of phlebotomine sand flies
Hlavačková, Kristýna ; Dvořák, Vít (advisor) ; Straka, Jakub (referee)
This diploma thesis is focused on species identification of sand flies belonging to two genera of the subfamily Phlebotominae, genus Phlebotomus and Sergentomyia. Genus Phlebotomus together with the genus Lutzomyia of New World include the only proven vectors of Leishmania parasites and they are also carriers of viral and bacterial infections. Species of the genus Sergentomyia are proven vectors of sister genus Sauroleishmania that infects reptiles, but for several decades there have been speculations about their possible involvement in the transmission of mammalian Leishmania species. These suspicions arise mainly from repeated findings of mammalian Leishmania parasites in their digestive system. Correct species determination of medically significant hematophagous arthropods is very important especially for purposes of epidemiological studies so that efficient vector control may be correctly set. Routine identification of sand flies is based on morphological characters located mainly on their heads and genitalia. However, these characters may be variable within a species, they require certain expertise and in the field samples they may be damaged, making proper species identification impossible. This thesis therefore presents two alternatives of sand fly identification based on molecular...
Biology of solitary bees of various families (Hymenoptera: Apoidea). A comarative study.
Žáková, Zdislava ; Straka, Jakub (advisor) ; Bogusch, Petr (referee)
The diploma thesis deals nesting behavior of the solitary bees Colletidae, Megachilidae, Mellitidae, Halictidae. The bees were monitored in their natural environment in the years 2009 - 2010. Course of their daily activities, number of nests per female, lenght of stay in the nest, length of life, active days and other species characteristics were monitored. By comparing the different nesting behavior patterns of the monitored species were found and pointed out the ones that are common and the unique ones. A nest uzurpation occurred (at all colonies) regardless the species. The (research) literature does not adress the issue of nest uzurpation in detail. Key words: nesting behavior, uzurpation, agression, bees, Hymenoptera
Host specialization and species diversity in Strepsiptera of the genus Stylops
Jůzová, Kateřina ; Straka, Jakub (advisor) ; Malenovský, Igor (referee)
The twisted-wing parasites (Strepsiptera) are entomophagous insect order with cosmopolitan distribution. There are about 600 known species up to date. In spite of this, they have very broad host spectrum. Strepsiptera parasites in seven insect groups (Thysanura, Blattodea, Mantodea, Orthoptera, Hemiptera, Diptera, Hymenoptera). The mutual relationship between genera or even between species are not known, except for the species list and the host specification. Moreover, there is an anambiguous use of their species concept. Some authors consider Strepsiptera as the specialists and they match almost every host species with one separate strepsipteran parasite. The opposite concept is to consider strepsiptera as the generalists. The presence of the crypctic species also affect our understanding of the diversity of Strepsiptera. Therefore, the knowledge of Strepsiptera phylogeny provide us the important information about species diversity of studied group as well as about their coevolution with their hosts. On the basis of molecular analyses of three genes constructed the phylogeny genus Stylops. This genus has the wider spetrum of the host species from other strepsipterans of Stylopidae, It is obvious, that strepsipterans of genus Stylops are mainly specialised on their host subgenus. There was detected two...
Characteristic population genetics features of animals with parasitic life strategy
Kodejš, Karel ; Straka, Jakub (advisor) ; Synek, Petr (referee)
Organisms with parasitic life strategy are characterized by strong bond to their hosts. Becouse of that can their population history, or more generaly their phylogeny, reflect evolutionary history of the hosts. While with morphological markers alone, coevolution can be examined only at higher, at least species level, the development of molecular techniques, especially usage of selectively neutral markers, provides deeper insight in this problematics. This thesis describes genetic markers used to investigate population dynamics, with emphasis to parasitic animals, and sumarises their advantages, limitations and possible applications. Further it describes statistical methods used in coevolutionary studies, mainly to reconstruct coevolutionary history. It describes basic statistical algorhytms to characterize rate of population subdivision. In the last part it describes parasite and host's life history features, which influence characteristics of coevolution, such as rate of host specificity, complexity of life cycle, host and parasite's mobility, which has impact to final coevolutionary pattern. Keywords: parasitism, population genetics, genetic markers, coevolution, biostatistics, microsatellites
Nesting behaviour and population genetics of solitary bees (Hymenoptera: Anthophila)
Černá, Kateřina ; Straka, Jakub (advisor) ; Žďárek, Jan (referee) ; Paxton, Robert J. (referee)
My thesis is focused on nesting behaviour and population genetics of solitary bees. These two topics, although seemingly unrelated, bring much new information and thus contribute to the better understanding of solitary bee biology that is still insufficiently known. Although the solitary behaviour represents the necessary original state for the evolution of higher sociality or obligate cleptoparasitism, its role is largely unappreciated. Furthermore, intraspecific cleptoparasitism, which is an alternative and facultative nesting strategy in bees, is a probable antecedent state of obligate cleptoparasitism. Although the obligate cleptoparasitism is a very common strategy in solitary bees, the information about the frequency and the occurrence of intraspecific cleptoparasitism in solitary bees is rare. We studied the nesting behaviour of solitary bees to detect different behavioural patterns that could serve as preadaptations to sociality or cleptoparasitic behaviour and we also focused on the detection and description of intraspecific cleptoparasitism in solitary bees. We chose four model solitary species for these studies - Andrena vaga (Andrenidae), Anthophora plumipes (Apidae), Colletes cunnicularius (Colletidae) and Osmia rufa (Megachilidae). We described the behaviour of Andrena vaga at the...

National Repository of Grey Literature : 59 records found   1 - 10nextend  jump to record:
See also: similar author names
16 STRAKA, Jakub
9 STRAKA, Jan
9 Straka, Jan
6 Straka, Jiří
3 Straka, Josef
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