|
|
Mortality of small animals on singletrails in Marianské údolí valley (Brno, Czech Republic)
Homolka, Miloslav ; Mikulka, O. ; Kamler, J. ; Drimaj, J. ; Plhal, R.
Singletrail areas became a part of tourist business all over the world. Cycling routes usually go through the natural environment, they are used especially in the summer and therefore are quite evident that small animals are killed on them. The submitted contribution indicates what effects have the traffic on the singletrail on small animals in the deciduous forest environment (Brno, Czech Republic). During singletrail traffic insects and small vertebrates were killed. The number of cadavers of individual species was relatively small on the trails (3800 individuals of insect and 51 of vertebrates one during 3 months on the 11 km of the route) and traffic most probably does not endanger the existence of any animal species at the local population level. Mostly the common species were perished on the trails, but individuals of specially protected and endangered species were also killed there (Calosoma sycophanta, Bombus spp., Anguis fragilis, Bufo bufo) so this fact should not be overlooked and underestimated. For ethical and educational reasons, the construction of new singletrail areas should be preceded by careful research of particular area in order to map the distribution of small animals and choose the route with regard to minimizing mortality, especially endangered species of fauna.
|
|
|
Methodological problems of the analyses of insect decline
Chlup, Petr ; Storch, David (advisor) ; Sedláček, Ondřej (referee)
In recent years, several studies reporting a severe decline of insect populations across several continents turned the spotlight on the problem of insect decline. However, the reported declining parameters may vary, and it is necessary to differentiate between declines in biomass, abundance, diversity, or geographical range reduction. This thesis aims to summarize how the conclusions about insect decline are shaped by the methods researchers use, especially by the variables they measure, emphasizing the potential methodological issues and limitations of the various facets of insect decline. Furthermore, we offer a brief digest of the most relevant potential biases and interpretative risks threatening population monitoring surveys. The review also provides concise insight into the state of knowledge on the matter of insect population trends. Keywords: insects, insect decline, insect population trends, methodology, methodological issues
|
|
|
Reactions of spider and insect predators to aposematic prey
Koláčná, Klára ; Exnerová, Alice (advisor) ; Sentenská, Lenka (referee)
Aposematic prey advertises its unprofitability to predators by means of warning signals, which can be visual, chemical, acoustic or combined with each other as multimodal signals. Most experimental studies dealing with responses of predators to aposematic prey focus on vertebrates, especially birds. This thesis focuses on the most frequently tested groups of terrestrial arthropod predators - spiders, dragonflies, and mantises - supplemented by less tested insect predators. Most of the tested arthropod predators are able to learn to avoid noxious aposematic prey based on either visual, olfactory or acoustic signals depending on their perception. Some can remember this aversion for several days. Only in case of jumping spiders, ability to generalise previous experience with a particular prey to similar prey has been confirmed. Prey chemical defenses most often consist of cardenolides or aldehydes, which proved to be aversive for tested arthropod predators.
|
|
|
Evolutionary history, systematics and biogeography of Southern Hemisphere hydrophilid beetles (Coleoptera)
Seidel, Matthias ; Fikáček, Martin (advisor) ; Gomez-Zurita, Jesus (referee) ; Gimmel, Matthew L. (referee)
The research presented in my PhD thesis consists of phylogenetic, biogeographic, taxonomic and ecological research of Southern Hemisphere water scavenger beetles (Coleoptera: Hydrophilidae) with a special emphasis on New Zealand. The introductory chapter provides a brief outline on the break-up of Gondwana and geological processes that shaped New Zealand and its fauna. Furthermore, the diversity of New Zealand Hydrophilidae and worldwide diversity of the hydrophilid subfamily Cylominae and its taxonomic history are illustrated. The scientific part of the thesis contains 4 published papers and 2 manuscripts. The first study recalibrates the Coleoptera time tree, providing new age estimates for the Hydrophiloidea, among others. The new age estimate is implemented in the second study, a phylogenetic study that reconstructs the biogeography of the 'Gondwanan' Cylominae beetles. The Cylominae, whose name was reinstated through nomenclatural priority over Rygmodinae in a separate paper, are found to consist of two tribes, Andotypini and Cylomini. The disjunct distribution of Cylominae is shown to be partly the result of vicariance and partly of long-distance oversea dispersal. The most remarkable long-distance dispersal is that of the only African representative of the subfamily which reached Africa from...
|
|
|
Methods in research of insects mobility
Jor, Tomáš ; Hadrava, Jiří (advisor) ; Lučan, Radek (referee)
Mobility is one of the basics characteristics of the insects populations. This bachelor thesis presents a compendium of methods used in research of insects mobility. In the first part are described methods of marking individuals utilized for Mark-Recapture studies aiming to study insects movements. First are presented the indirect methods of individuals tracking, further the methods of direct tracking of insects using a radio-telemetry are described. In the second part the thesis focused on modeling of insects mobility using dispersion functions with connection to metapopulation dynamics and a dispersion itself. Difusion model based methods and simpler estimates of movemensts are also presented in this part. Key words: Insects, Mobility, Mark-Recapture, Modeling
|
|
|
Stable isotopes and the study of insects ecology
Javůrková, Jaroslava ; Šípek, Petr (advisor) ; Harant, Karel (referee)
Animal foraging ecology is an important part in the puzzle ecosystem relationships. This bachelor thesis presents review in the field of food ecology, especially insects. It focuses on the method of analysis of stable isotopes, which is one of the current and in recent decades a modern approach for studying this issue. Stable isotope analysis is compared with other frequently used methods for animal food ecology. The aim of this work is to introduce this method and its possible use in the study of insect food ecology. The first part provides the necessary theoretical background, practical application in laboratory and then it deals with the problems typically adressed by this method. Key words: stable isotopes, stable isotopes analysis, food ecology, food preferences, insects
|
|
| |
|
|
Importance of UV perception for dragonflies (Odonata)
Jačmeněv, Vjačeslav ; Černý, Martin (advisor) ; Stella, David (referee)
It has long been known that some animals are able to perceive radiation at other wavelengths than perceive we humans. In dragonflies, UV sensitivity has been demonstrated in the 1974, however a recent study has unveiled an extraordinary diversity of genes of specific photoreceptor proteins known as opsins, including UV-sensitive opsin. In addition some dragonflies have coloration on their body and wings, which can reflect UV radiation at unchanged wavelength - UV reflectance. Very little is known about the use of UV in dragonfly life. My thesis summarizes the current knowledge of the importance of UV for dragonflies, focusing on interspecific and intraspecific communication.
|
|
|
Functions of myrmecomorphy in the arthropods and its occurrence and potential functions in true bugs
Hrebiková, Tereza ; Exnerová, Alice (advisor) ; Pipek, Pavel (referee)
Myrmecomorphy (ant mimicry) is structural and chromatic (sometimes also chemical and behavioural) resemblance to ants. Ant-mimicking species can be found in many arthropod taxa particularly in spiders and true bugs. Myrmecomorphy may serve several functions, protecting the mimics either from the ants themselves or from predators. Mechanisms of ant mimicry have been studied mostly in spiders and some insect taxa (e.g. beetles). In true bugs (Hemiptera: Heteroptera), ant mimicry exists in many species belonging to several families, and it is present in both larvae and adults. Notwithstanding its frequent occurrence, the literature about ant mimicry in true bugs is limited only to several incomplete lists of myrmecomorphic species, hypotheses on mimicry functions, and a few experimental studies. This thesis aims to review (1) experimental studies focused on function of ant mimicry in spiders and insects and (2) occurrence, form and potential function of ant mimicry in true bugs (Heteroptera). Key words: Myrmecomorphy, function, Arthropoda, spiders, insects, Heteroptera
|
|
|
Determination of basic nutritional parameters in edible insects
Korček, Jakub ; Štursa, Václav (referee) ; Diviš, Pavel (advisor)
In this bachelor thesis is dicussed nutritional value of chosen insect species. Analysed samples consisted of worms, crickets and locusts. Analysed parameters were: total nitrogen, crude protein, total lipids and content of chosen elements. Total lipids were, after homogenization, determined by Soxhlet method, using diethyl ether as a solvent. Prior to protein and element determination, samples did undergo Kjehldal digestion process, using sulfuric acid. Weiniger catalyst was only added to samples digested for protein measurement. Element content was determined by optical emission spectrometry with inductively coupled plasma (ICP-OES). Crude protein was determined by Kjeldahl method. The highest protein content was determined in crickets. (75 ± 5) %. Locusts contained the highest lipid content (33 ± 2) %. We also found out, that samples were rich in calcium, potassium, manganese and zinc, which are all important elements for the proper functioning of our body. The results of this thesis prove, that insects can present nutritionally important food.
|
guest ::
