The rapid adaptation of insect species on environment changes can represent a significant advantage for their development and consequently a great negative effect for the stability of forest ecosystems. Larval individuals of Cabera pusaria and Lymantria dispar and adults of Melolontha hippocastani and Phillobius arborator is in general widely expanded species of herbivorous insects in European regions and with them are connected huge economic and ecological losses. The composition of food (biogenic elements, trace elements, heavy metals, proteins, carbohydrates etc.) is the main parameter of food quality. Laboratory experiment with natural diet (assimilation apparatus of Quercus petraea and Betula pendula) in control conditions (temperature, humidity, and light) were used for determination of insects’ reactions to increased concentration of manganese in the diet. Food was contaminated by soaking in solutions of MnCl2.4H2O with graded manganese concentrations. On the base of experiment design and character of reared experimental species we determined the food consumption, the activity period of adults, the mortality of larvae, the quantity of eggs laying, the dry mass and live weight of experimental individuals, concentrations of manganese in unconsumed food, excrement and lyophilized bodies, larval and pupal exuviae. Mentioned parameters were observed for determination of reactions of experimental insect species on changed food quality via the presence of high manganese contents. The results showed, that the reactions of individual experimental animals were very different. We observed the negative reaction to high manganese content in the diet of L. dispar larvae with the tendency of its compensation (the increasing food consumption rate and prolongation of development). Caterpillars of C. pusaria were very sensitive to changed food quality and therefore we observed high mortality. On the other side, the high manganese content in the diet of P. arborator in the laboratory conditions influenced neither their food intake nor their mortality. For individuals of M. hippocastani very high content of manganese in the diet significantly influenced the food consumption and thereby their development(distortion of copulation and consequent eggs laying). We observed the repellent effect of high levels of manganese in the diet. In all cases, the elimination mechanisms of surplus manganese in the diet were observed. Individuals in experiments exuded manganese through the digestive system into excrements and by incorporation of it into unspecified parts of their adult body without direct physiology activity or in exuviae of caterpillars.
| Identifer | oai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:425092 |
| Date | January 2018 |
| Creators | Martinek, Petr |
| Source Sets | Czech ETDs |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/doctoralThesis |
| Rights | info:eu-repo/semantics/restrictedAccess |
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