This thesis deals with biting midges of the genus Culicoides, which are tiny nematoceran insects belonging to the Diptera, and their parasites. Biting midges partake in transmissions of several parasitical organisms of various groups. Most notably, they are the vectors of several pathogenic viruses which might have a serious impact on livestock. However, the thesis deals with detection of parasites belonging to Trypanosomatids and Filarioids related to two independent biting midges collections - from the Czech Republic and from the Central African region. Apart from testing biting midges, there were carried out the tests on the occurrence of the same group of parasites within ruminant hoofed games in the Czech Republic. Our goal was to find out whether the same parasites occur with biting midges and their hosts (hoofed games) and whether biting midges could play a role as vectors. Biting midges are relatively overlooked group of haematophagous insects. Until recently, they had not been paid much attention, which changed with the spread of Bluetongue virus over Europe. This stimulated a widespread monitoring of biting midges in several European countries, including the Czech Republic. This helped to gain a large amount of data about the occurrence of biting midges near livestock. Nevertheless, there is no...

The class Kinetoplastea contains free-living and parasitic species. One of the most dominant group within the class is the order Trypanosomatida which includes obligate parasites (Trypanosoma, Leishmania) infecting a wide range of hosts. Some species are serious pathogens of humans and domestic animals and cause considerable losses. However, the majority of trypanosomatids belongs to monoxenous parasites of insect which are usually harmless to their hosts. Monoxenous trypanosomatids predominantly infect Hemiptera and Diptera. This diploma thesis is focused on the detection of monoxenous trypanosomatids in cockroaches captured in the Czech Republic and cockroaches from different breedings. Cockroaches are very suitable mechanical vectors of many different pathogens (including parasites) and are significant health threat for humans and animals. First trypanosomatids in cockroaches were documented at the beginning of the 20th century, but there is no study focused on this topic specifically. Another aim of this thesis is morphological and ultramicroscopic analysis and the study of the host specificity of the recently described species Herpetomonas tarakana, isolated from a cockroach. My findings were partly used in the already published study "Diversity of trypanosomatids in cockroaches and the...

Phlebotomine sandflies are blood sucking Dipteran and important vectors of various patogens, especially leishmania parasites (Trypanosomatida, Leishmaniinae). Apart from the genus Leishmania they also transmit variety of other parasites and they are considered to be vectors of trypanosomes (genus Trypanosoma) and hosts of some monoxenous trypanosomatids. This Master thesis is focused on the occurrence and development of mono- and dixenous trypanosomatids (other than the genus Leishmania) in sandflies. We studied experimental infections of various species of sandflies and mosquitoes by two species of trypanosomes and one species of monoxenous parasite (Strigomonas galati). All three studied trypanosomatid species were isolated from sandflies. Further concern of the thesis is the transmission of both species of trypanosomes from sandflies to vertebrate hosts and the transmission of monoxenous parasite between insect hosts and also morphological changes of parasite cells during the development in a culture and in the insect and vertebrate hosts.

The increased honey bee colony losses in the last decade gain a considerable attention of scientists and public. The causes of these losses include a wide range of biotic and abiotic factors, but pathogens and parasites are probably the main ones. Monoxenous trypanosomatids in honey bee gut Lotmaria passim and Crithidia mellificae were neglected for a long time but according to recent studies they seem to participate in those colony declines. Trypanosomatids are widespread parasites, including also the causes of some human illnesses, such as sleeping sickness, Chagas disease and leishmaniasis. The mechanism of the effect on honey bee health is not well understood so far. The aim of this thesis was to verify the occurrence of the trypanosomatids in honey bee samples from two regions in Czech Republic. The methods, based on detection of specific DNA loci, confirm the high prevalence of L. passim, which was founded in majority (71 %) of the samples. On the contrary, no samples were positive to C. mellificae.