Honey bee population decline has been attributed to a variety of causes including infestation of hives with Varroa destructor mites. Fluvalinate has been extensively used in the United States to combat these mites for nearly 30 years, despite its high toxicity to honey bees. The objectives of the current research project were to investigate the extent of fluvalinate contamination in commercially available wax and to define exposure pathways from the contaminated wax and fluvalinate-impregnated strips to larval and adult honey bees. All of the commercial wax tested in the current study contained elevated fluvalinate concentrations, ranging from 170 to 1040 ng/g wet weight, indicating a need for regulation of the sources of wax being rendered for resale. Based on the negative logarithm of the partition coefficient between wax and pollen (-0.54) and the fact that all of the tested wax samples contained elevated concentrations of fluvalinate, it is evident that fluvalinate has the potential to actively transfer from the contaminated wax into bee hive matrices. This point was confirmed by adding fluvalinate-dosed wax, fluvalinate-impregnated strips, or a combination of the two to 10-frame hives. Larvae and adult bees from those hives were checked for fluvalinate exposure using gas chromatography-mass spectrometry analysis. Larvae had detectable concentrations of fluvalinate in all three treatments. Bioaccumulation in adult bees was significantly affected by the interaction between treatment type and application time. In other words, residues were comparable from hives that only had fluvalinate-dosed wax to those that were actively being treated with impregnated strips, strongly suggesting that transfer of fluvalinate from wax into adult bees was an important exposure route. In conclusion, exposure of fluvalinate from contaminated wax and treatment strips to larvae and adult honey bees is an important factor that needs to be considered when applying miticides and evaluating risk in honey bee hives.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

My thesis is devoted to the resistance of pollen beetle (Meligethes aeneus, son. Brassicogethes aeneus Fabricius, 1775) to pesticides in selected localities in southern Moravia. Collecting adults was performed in the spring of 2013 by tapped into polyethylene bags. Adults are collected from the stands of oilseed rape, mustard and poppy. Tests were performed on the basis of the methodology of Insecticide Resistance Action Committee number 011, 021, 025. In total, we tested the pollen population from 18 locations. For testing, we used the following chemical substances: Biscaya 240 OD, cypermethrin, lambda-cyhalothrin, tau-fluvalinate, etofenprox, chlorpyrifos(ethyl). We evaluated 100% of the registered dose of pesticides after 24 hours. From the results of the individual populations, we found large differences in resistance to chemicals.

Resistence population of pollen beattle on selected locations of Moravia and Silesia were observed during the 2017. Beattles were taked off in the field during spring and their sensitivity to insecticides active substances indoxacarb, chlorpyrifos, thiacloprid, tau-fluvalinate, cypermethrin and lambda-cyhalothrin were tested in laboratory. Tested using methods of IRAC – 11, 21, 25 and 27. Mortality of beattles at various concentrations of active substances was evaluated after 24 hours. Levels of resistance were changed for individual location.

This thesis was compiled during the solution of the project MA NAZV QJ1230077 and it is focuses on monitoring of pollen beetle (Brassicogethes aeneus, Fab., 1775) populations resistence to selected insecticides, in particular lambda-cyhalotrin, cypermetrin, tau-fluvalinate, Biscaya 240 OD and chlorpyrifos-ethyl in South Moravia. Beetles were collected during the spring 2016. Their sensitivity to these insecticides active ingredients was tested in laboratory. Various concentrations of active substances and beetles´ mortality after 24 hours was evaluated according to methodology IRAC (adult-vial-test met. 11, 21, 25, www.irac-online.org). Beetles´ sensitivity depends on the dose of the active substance and the location where the beetles were taken from.