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Efekt podpory výskytu přirozených predátorů škůdců na zdraví a vitalitu ovocných dřevin
Bernatová, Martina
Predators (both invertebrates and vertebrates) can have a positive or negative effect on the vitality and physiological processes of woody plants. However, the mutual effect and interaction of several different groups of predators and their influence by different habitat manipulations is still not well known. For this reason, the aim of my work was to find out how biological control, i.e. manipulation to support invertebrate predators, and, conversely, the exclusion of insectivorous predators from vertebrates (birds, bats), or a combination of these two manipulations, will affect the vitality (and health status) of fruit trees, specifically pear. The experiment took place in organic pear orchards in the Zlín and South Moravian Regions. In each orchard (n = 4), 16 trees were selected and divided into groups of 4 trees differing according to the type of manipulation: a) installation of cardboard bands to support invertebrate predators, b) construction with a net to exclude the access of birds and bats, c) combination of cardboard bands and structure with net, d) control tree. The experiment started in the autumn of 2021 with the instalation of cardboard bands and in the spring of 2022 with the instalation of structures with nets for exclusion of birds. During the season (from May to September 2022), samples were collected to determine and compare leaf biomass and herbivory, fruit biomass and damage, and the efficiency of photosynthesis and the content of chlorophyll in the leaves were also measured, as well as the leaf area index. Overall, the results showed a significant positive effect of the manipulations on pear vitality. The best vitality was recorded for trees with a combination of cardboard bands and exclusion of birds and bats. The results show the importance of supporting natural predators of pests (mainly spiders). On the contrary, it is evident that these interactions could be disturbed by insectivorous birds (bats), which have a significant predation effect on spiders and thus can have a cascading effect on the vitality of fruit trees.
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Influence of potato seed coating with entomopathogenic and mycoparasitic fungi on the yield and quality of potato tubers
SOBOLÍK, Martin
Quality seed plays an important role in potato cultivation. Only recognised and certified seed potatoes should be used for planting. The health of the seed potatoes is therefore an important parameter. In the bachelor thesis, the effect of seedling coated with the entomopathogenic fungus Metarhizium brunneum and the mycoparasitic fungusTrichoderma virens on yield-forming parameters and the health status of the crop and subsequently harvested tubers was investigated. Both beneficial fungal species M. brunneum and T. virens had a positive effect on the growth and development of potato plant. In particular, the mycoparasitic fungus T. virens positively affected growth parameters in plants. Plants from seedlings coated with M. brunneum produced largerer and heavier tubers in compare to the control and T. virens variants. During the vegetation, the M. brunneum variant had statistically the lowest number of larvae and adults of the Leptinotarsa decemlineata. From the data, it was found that the highest actual yield was achieved with the T. virens variant and the theoretical yield with the M. brunneum variant. The BP results suggest that biological methods of plant protection by using of beneficial fungi for coating seeds can be used as an Potato Integrated Pest Management.
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Use of macroorganisms and microorganisms in biological control of aphids
BOŠKA, David
Aphids are one of the most important species of pests, occurring on all continents except Antarctica. Aphids are harmful mainly by sucking, honeydew production and transmitting hundreds of viral diseases. The most important greenhouse aphids occurring in the Czech Republic are the green peach aphid (Myzus persicae) and the cotton aphid (Aphis gossypii). Their danger lies in the rapid development cycle, when there is a rapid increase in populations. Despite the great damage they cause, aphids are very defenceless and small insect with a large number of naturally occurring enemies. The most important natural enemies are predators, parasitoids and entomopathogenic fungi. In the biological control of plants against aphids, the predator ladybeetles (Coccinellidae), lacewings (Chrysopidae) and the aphidophagous gall midge (Aphidoletes aphidimyza) are mainly used. In the nature, aphids are also regulated by hoverflies (Syrphidae). The most important aphid parasitoids are mainly the parasitic wasps Aphidius colemani, Aphidius ervi and Aphelinus abdominalis. From the microorganisms, the polyphagous entomopathogenic fungi are used, they cause primary infections in several species of pests. From the microorganisms, entomopathogenic fungi are mainly entomopathogenic fungi that can attack polyphagous more species of harmful organisms. The bioproducts based on entomopathogenic fungi Lecanicillium lecanii, Beauveria bassiana and Isaria fumosorosea are available on the foreign market. They were developed for biological control against aphids and other pests.
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Evaluation of development of various strains of Beauveria bassiana in different environmental conditions
ŠEBEK, Jaroslav
The entomopathogenic fungus Beauveria bassiana is a polyphagous species of fungus that attacks more than 700 species of hosts. This species of fungus is one of the most researched and most common representatives of entomopathogenic fungi. Many of bioproducts based on conidia or blastospores of B. bassiana are registered around the world. These bioproducts are used in biological control against various pests of field crops, fast-growing vegetables and ornamental flowers and in forest stands against certain pest species. The bachelor thesis focuses on the basic "in vitro" parameters of selected strains of entomopathogenic fungus B. bassiana from different geographical areas. The work focuses on the effect of temperature on the germination of strains of the entomopathogenic fungus B. bassiana. Furthermore, the growth and development of B. bassiana strains (radial growth) were compared. And the last part is focused on the comparison of spore production of strains of entomopathogenic fungus B. bassiana on standard nutrient medium and natural substrate.
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Evaluation of qualitative and quantitative parameters of entomopathogenic fungus \kur{Beauveria bassiana} related to the inoculum production temperature
RYBAROVÁ, Kateřina
Bachelor thesis is focusing on the entomopathogenic fungus Beauveria bassiana strain GHA, which is contained in the commercial bioproduct Botanigard. Botanigard is a product used in biological control in many countries around the world to control a wide range of pests of various plant species. In this thesis, "in vitro" (radial growth, spore production) and "in vivo" parameters (virulence) of the GHA strain of Beauveria bassiana were tested at various temperatures on different nutrient media. The most optimal temperature for radial growth of the GHA strain was 25 °C, on media with a nitrogen to carbon ratio of 20:20. The GHA strain produced the largest amount of conidia on the medium with a nitrogen/carbon ratio of 20:40 at temperature 25 °C. On the contrary, the smallest conidia production was obtained on medium PDA and nitrogen/carbon medium in ratio 5:10. The temperature of 25 °C was also the most optimal for the infection of larvae of Tenebrio molitor. Thesis also deals with the comparison of blastospores production of GHA strain with other strains of B. bassiana isolated from different geographical areas. The strain isolated in Argentina had the highest production of blastospores on MEB medium.
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Possibilities of use of selected entomopathogenic fungi in biological control of agricultural pest species
KONOPICKÁ, Jana
Ph.D. thesis is focused on the entomopathogenic fungi that can be used in biological control. Ph.D. thesis consists of two main parts: 1) a detailed background research, and 2) five subchapters of the experimental part and results, which contain original publications describing results of my own studies. The first study focused on the isolation and identification of new strains of entomopathogenic fungi from soil samples collected in garlic and onion fields in the Czech Republic and Israel. Furthermore, the efficacy of selected fungal strains against the bulb mite Rhizoglyphus robini was tested. A total of 5 genera of entomopathogenic fungi (Metarhizium sp., Beauveria sp., Isaria sp., Lecanicilium sp. and Purpureocillium sp.) were identified among the soil isolates from both countries. The most frequent was the genus Metarhizium sp. especially in sampling sites of the Czech Republic. The highest efficacy against Rhizoglyphus robini mites was found in Metarhizium anisopliae strains isolated from soil samples collected in the Czech Republic and in Metarhizium indigoticum strain from Israel. Mortality after 4 days of the bioassay was almost 100%. The second study investigated the efficacy of the entomopathogenic fungus Isaria fumosorosea CCM 8367 against box tree moth (Cydalima perspectalis). Fungal infection was mostly observed in pupae. However, mortality did not exceed 60%, indicating a very low susceptibility of box tree moth to Isaria fumosorosea CCM 8367. In the third subchapter, various strains of entomopathogenic fungus Beauveria bassiana were tested against the Colorado potato beetle, a serious pest of potato. First, laboratory experiments were performed and the most virulent strain BBA 08 against this pest was selected and used subsequently in further experiments. The strain efficacy against L. decemlineata adults was evaluated in pot experiments and under field conditions. The fungus was applied alone and in combination with entomopathogenic nematodes. In all experiments, the fungus reduced the number of Colorado potato beetle adults by about 30% compared to the control. The fourth study described enrichment of soil substrate with entomopathogenic fungus Isaria fumosorosea CCM 8367 for increasing its suppressivity. The results showed that the fungus successfully colonized the soil substrate and remained in it for more than 6 months at 20 °C, although the average concentration decreased slightly from 5.89×104 to 2.76×104 spores per milliliter of substrate during the experiment. The last study described dissemination of Isaria fumosorosea CCM 8367 spores by nematodes of Steinernema feltiae and Heterorhabditis bacteriophora. The results of our study revealed for the first time that the spread of conidia and blastospores of Isaria fumosorosea in soil environment is significantly enhanced by the presence of entomopathogenic nematodes.
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Use of entomopathogenic fungi in biological control against sweetpotato whitefly Bemisia tabaci
ŘEHOŘOVÁ, Markéta
The thesis is analyzing effects of selected species and strains of entomopathogenic fungi on the synchronized population of Bemisia tabaci under optimal and sub-optimal conditions. The following species of fungi were used during the experiments: Aschersonia aleyrodis, Lecanicillium lecanii (former Verticillium lecanii), Isaria fumosorosea (former Paecilomyces fumosoroseus) a Beauveria bassiana. There was a experiment of mortality of all these fungi in the frequency of 7, 14, and 21 days, while all these experiments were made under the same conditions (concerning temperature and humidity) in order to keep all the results comparable. In the case of Isaria fumosorosea, the experiment was taken also under sub-optimal conditions in order to compare effectiveness of this significant fungi, both under the optimal conditions (relative air humidity 95-100 %, temperature 25{$\pm$}1°C), and sub-optimal conditons (relative air humidity bellow 75 %, temperature 25{$\pm$}1°C). Greater attention was also given to A. aleyrodis which represents one of the most important fungi on the field of whitefly combat.
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The impact of herbivores on plant population dynamics: The importance for biological control of invasive plants
Šulcová, Hana ; Dostál, Petr (advisor) ; Kindlmann, Pavel (referee)
Herbivory is one of the most important relations between plants and animals. The herbivores affect plant populations not only by grazing, but also by trampling and disturbing the vegetation. Herbivores have also great potential to affect the population dynamics of particular plant species. The aim of this thesis is to evaluate the effect of herbivores on plant population dynamics and to interpret it in relation to biological control of invasive plants. When evaluating the effect of herbivores, it is necessary to keep in mind the fact that herbivores don't affect only plants but also each other through direct as well as indirect competition. The use of different herbivore species to supress the invasive plants may not necessarily be effective. The range of the effect of herbivores on plant population dynamics depends also on the environmental conditions. Habitats with infrequent disturbances and high competition levels among plants increase the effect of biological control, because high competition facilitates competitive exlusion of the target plant species. Different life-histories of plants play are also important in terms of biological control mainly the life-span and the endurance of the seed bank affect the results. Monocarpic species with short-lived seed bank can be relatively easily reduced by...
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