|
|
Biogeography and host spectrum of twisted-wings (Strepsiptera)
Benda, Daniel ; Straka, Jakub (advisor) ; Malenovský, Igor (referee)
Twisted-wings (Strepsiptera) are an endoparazitic order of insects with cosmopolitan distribution, which are sister group of Coleoptera. There are 7 known host insect orders. As a group with relatively small number of species (almost 600) and cryptic way of life, Strepsiptera were usually overlooked by entomologists. Majority of publications about Strepsiptera deal simply with describtion of new species. For many taxa of basal families, the host group is unknown, because just free flying male has been collected and described. In contrary, only a female collected with host is known in some species. In derived families Xenidae and Stylopidae (parasitize Hymenoptera: Aculeata), there are known hosts in overwhelming majority of species. Many information about distribution of these groups can be extracted also from publications about hosts, where stylopized individuals are mentioned. Presented thesis summarizes the distribution of Strepsiptera at the level of families and genera. It also provides an assessment of the occurrens of Strepsiptera in different biogeographic regions with focus on their hosts. Keywords: Twisted-wings, Strepsiptera, distribution, parasites, host group, biogeography
|
|
|
Evolution of sting and associated venom gland in Hymenoptera (Aculeata)
Matějková, Zuzana ; Straka, Jakub (advisor) ; Šobotník, Jan (referee)
Theme: Evolution of the sting and associated glands in Hymenoptera (Aculeata) Author: Zuzana Matějková Supervisor: Mgr. Jakub Straka, Ph.D. Abstract A stinger is a synapomorphy of Aculeata group. The branch of Aculeata has cleaved from the Parasitica group - they both belong to the order Apocrita. The stinger of Aculeata has evolved from a former ovipositor - though the function of laying eggs has been lost. Besides venom gland several other glands including Dufour's gland vent into a stinger. The original (parasitic-predator strategy- binding) function of the gland excretes is a paralysis of the prey. In social Aculeata it gains a defensive function - associated with a possible act of autotomy of the stinger. The stinger and associated glands are also a source of pheromones and small peptides with an antimicrobial function. These peptides act together with other venom components and they help to improve its effectiveness.
|
|
|
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...
|
|
|
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...
|
|
|
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...
|
|
| |
|
|
Termite behaviour and polyethisms during colony defence
Homolka, Petr ; Šobotník, Jan (advisor) ; Straka, Jakub (referee)
My bachelor thesis deals with the various defensive adaptations of termites, not only in specialized caste of defenders, the soldiers, but also in members of other castes. Termites are the eldest group of eusocial insects on the planet and their defence systems are indeed impressive. I tried to describe the defensive strategies in general, morphological, anatomical and behavioral adaptations of termites to defence, and also major termites enemies. At the end I also sum up the knowledge on polyethism, which should be the aim of my future thesis.
|
|
|
Evolution of host specifity in cuckoo bees of the genus Sphecodes (Hymenoptera)
Habermannová, Jana ; Straka, Jakub (advisor) ; Kratochvíl, Lukáš (referee)
Cuckoo bees behave similarly to the well-known birds, cuckoos - they lay eggs in the nests of other bees. Proposed thesis charts the evolution of host specialization within the strictly cuckoo genus Sphecodes. According to the classical view based on the Red Queen hypothesis, parasites should gradually specialize during evolution to keep pace in the "arms race" with their hosts. Specialization is also perceived as an evolutionary dead end - narrow adaptation prevents change of host. To test these hypotheses phylogeny of tribus Sphecodini based on the partial sequences of five genes was constructed. For each ancestor has been by two methods of mapping ancestral characters (Bayesian method, Maximum Parsimony) specified, whether it was specialist or generalist and which kind of host or hosts it had. The results show that the original strategy of genus Sphecodes is specialization and generalists originated from specialized ancestors only recently. The results also show that the jumps between the hosts are common. These findings are inconsistent with the Red Queen hypothesis as well as with the view that specialization is an evolutionary dead end. Falsity of these hypotheses within the genus Sphecodes established also likelihood ratio test, in which the likelihood of model allowing two-way transition...
|
|
|
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
|
|
|
Nesting biology and alternative reproductive strategies in bees of the genus Anthophora (Hymenoptera)
Macháčková, Lenka ; Straka, Jakub (advisor) ; Tropek, Robert (referee)
My thesis is focused on the nesting behaviour and reproductive strategies of solitary bee Anthophora plumipes, which nests in colonies and builds the nests in the ground. During behavioral observation in seasons 2009 and 2010 the basic demographic characteristics of studied species were described and all the observed behavioral patterns were described in ethogram. Existence of intraspecific cleptoparasitism in form of usurpations was proved. From field usurpations were 22-33 % assessed as a real usurpations and 66-67 % were cases of use of an empty nests. Number of usurpation was constant throughout the season. There was increase in cases of use of empty nests at the end of the season. The underground nests were marked by lanthanides. This way the interactions between females could bee observed. In this way the intraspecific cleptoparasitism could be found out. 25-32 % samples were positive from 152 samples, that were measured on ICP. It suggests relatively low effectivity of marking. The mark losses reach up to 42 % during processing.
|
guest ::
RSS feed.