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Midgut proteinases in diapausing and post-diapausing adult of the spruce bark beetke \kur{(Ips typographus)}
ŠTEFKOVÁ, Kristýna
My work concentrates on feeding behavior of overwintering diapausing and post {--} diapausing bark beetles and developmental treshold. This is done either biochemically by measuring the enzymatic activity in the midgut and by assessing the feeding status from the size and consistence of the food bolus in the gut. Detailed knowledge of feeding behaviour and development treshold may help to predict the overwintering success of local populations with all the consequencies for spring dispersal and reproduction.
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Seasonal changes of adipokinetic hormone in spruce bark beetle \kur{(Ips typographus} L.)
MORAVCOVÁ, Martina
The aim of the thesis was to analyze and to quantify the adipokinetic hormones (AKHs) of the spruce bark beetle Ips typographus. The RP HPLC was employed for the AKHs identification, and a competitive ELISA for their quantification. Those methods indicated that the Peram-CAH-I and Peram-CAH-II could be the AKH representatives, and that their levels fluctuate during a year. The results also suggested that the hormones might substitute themselves within certain periods of the year.
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Relationship between \kur{Ips typographus} outbreak and Norway spruce ecosystem status in the Černá hora Mt. and Smrčina Mt. (Šumava National Park)
VAČKÁŘOVÁ, Tereza
The aim of the thesis was to find out whether there is a relation between spruce-bark beetle infestation and health condition of spruce stands. The field work was conducted in Šumava National Park on two research plots ? Černá Hora and Smrčina. In order to determine the health condition of spruce stands the methodology according to Cudlín et al. (2001) was used. The emphasis was put mainly on monitoring the percentage of individual parts of tree crowns, total defoliation, defoliation of primary structure and percentage of secondary shoots. According to the parameters the rate of crown structure transformation was identified and the trees were classified into four stress categories. All the monitored research plots, founded in spring 2009, with an exception of plot ?B? in Černá hora, were infested with a spruce-bark beetle. Only a single tree infested in 2009 was identified in plot ?C?. The methodology according to Jakuš et al. (2009 and 2010) was used to periodically monitor spruce-bark beetle invasion and individual reaction phases of the spruce stands. Furthermore, according to the data obtained a layer of tree occurrence in various stages of bark beetle infestation was constructed in GIS platform using ArcView 9.3 programme. It enabled us to determine the degree into which the bark beetle infestation and consequent colonization of surrounding trees is dependent upon the trees´ mutual position and their crown conditions. A hypothesis that a spruce-bark beetle prefers trees with a more transformed crown structure (Moravec at al. 2002) was proved only on the plots in Smrčina. The thesis should contribute to the study of mutual dependence between bark beetle infestation and spruce stands health condition as well as to their development in reaction to such infestation.
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