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Hospodářský význam chrousta Melolontha hippocastani F. v gradačním území LS Strážnice
Opavský, Tomáš
The aim of this work was to assess the presence of the chestnut cockchafer in LS Strážnice, primarily on the Vracov and Bzenec areas. Using the soil probes the etiology and abundance of the grubs in the soil profile were examined. The current population density of the chestnut cockchafer in this area has been compared with historical damage. Based on the evaluation of health status of the seedlings, the damage caused on planting in the Bzenec area from 2013 and 2014 was evaluated financially. In older cultures of the age 5-10 years, the ability to regenerate trees after being infested by grubs was evaluated. The course and the intensity of swarming were evaluated by light traps. Climatic conditions were scanned via usage of meteorological stations. The ovaries of the deceased females were examined by autopsy. Selection of the laying place of the females was analyzed from the historical materials. The results of the work proved that there is an ever-increasing population of Melolontha hippocastani F. in area of LS Strážnice. Economic loss on planting in the Bzenec area in the years 2013-2014 exceeded 2.5 million Czech crowns. At a time when roots are not eat by grubs, slightly damaged pine trees can regenerate. The number of captured imagos in the Vracov area exceeded all quantity recorded in previous years. The first eggs ready for laying appeared on females on May 6, 2015. The selection of the oviposition site of the females was evaluated with the preference of laying in the old stands.
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Faktory ovlivňující obnovu lesa na požářišti u Bzence (LS Strážnice)
Jarošová, Veronika
The aim of this bachelor thesis was to determine the current status of the population of beetle maďalového in the area of fire residues in the forest governance of Bzenec Strážnice and its surroundings. A fire broke out at the end of May 2012 and damaged the area of almost 165 ha of forest. First instar grubs, which were present in soil of burnt vegetation at the time, were not hit by the fire, and then these grubs caused enormous loss of spring planting in 2013. The soil of fire residues was tested with various methods of soil preparation, which would lead to reduction of the amount of beetle grubs maďalového. Out of these methods, the method of soil preparation with milling cutter with depth effect was the most effective one. Application of FORCE 1,5g insecticide had positive effect on the survival of planted seedlings. The dispersion of grubs, in the stand depending on the distance from the tree trunk and the amount of grubs depending on the age of original vegetation, had been investigated. The results showed that the grubs do not have a single concentration but are scattered along the stand depending on the root system, and they were mostly present in the stands of the second class.
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Chroust maďalový (Melolontha hippocastani F.) – hospodářský význam a možnosti eliminace škod v gradačním území LS Strážnice
Opavský, Tomáš
The aim of this work was to evaluate the amount of damage caused by the grubs of forest cockchafer. The damage was assessed in relation to the habitat conditions of the mining and cultivation practices. The pilot plant treatment of Actara 25 WG and Force 1.5 G was evaluated for efficacy against 2nd and 3rd grub instars. A methodical design of aerial intervention to inhibit the forest cockchafer during the 2019 swarming was drawn up. When evaluating the amount of damage, 59,233 pieces of seedlings were checked in 2017. The pilot plant treatment was applied to 4 473 pieces of seedlings and the application was carried out in seven different variants on three districts of the Forestry Administration in Strážnice. The average amount of damage caused by the infestation of forest cockchafer grubs in the Forestry Administration in 2016–2018 is 36%. The Actara 25 WG applied by irrigation was evaluated as the most efficient variant during pilot plant treatment. Based on the vegetation inspection and the extent of the damaged area, an aerial intervention was proposed in two variants to inhibit the forest cockchafer swarming in 2019.
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Ochrana lesa před chroustem maďalovým v gradačním území Moravské Sahary
Jarošová, Veronika
The aim of this master´s thesis was the evaluation of options that should lead to the elimination of the harmful effects of the white grubs of Melolontha hippocastani to the gradational area of Moravian Sahara (part of forest maintenance LS Stážnice, the Bzenec district). The effectiveness of chosen preparations (Force 1,5 G and Actara 25 WP) on the white grubs of Melolontha hippocastani was observed and conducted under controlled conditions in the ´container experiment´ with 380 seedlings of Pinus sylvestris. This experiment was repeatedly conducted five times over a period of 3 years. The results show that the most effective preparation against the white grubs is Actara 25 WG (200 up to 400 g/ha/600 l water) in the form of watering. This preparation in the form of spraying was ineffective. Inconsistent results were reached with the preparation Force 1,5 G. At the same time, the vertical movements of white grubs during their development stages in the soil were being observed over the period of 2015–2018. This observation took place in the drill holes of the following proportions 50 x 50 x 60–140 cm. The results confirmed that the depth of wintering of the white grubs and their movements during their vegetative state depends on the soil´s temperature and moisture, and the available sources of food to the current instar of the white grub.
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Chroust Melolontha hippocastani Fabr. významný škůdce lesních porostů LS Choceň
Hejda, Vojtěch
Bachelor thesis monitors the occurrence of may beetle Melolontha hippocastani Fabr. on the ground Vysoká under the forest management Choceň. Control was an area of 1020 ha of the total area of 1363 ha basin. Control methods for the detection of grubs, soil probes, the results were used to define the occurrence of grubs. Habitat conditions of vegetation, where the grubs occurred were used for the determination of suitable sites for development may beetle. Using geospatial technology was developed to map the definition of occurrence grubs June bugs in the district Vysoká.
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