Epsilon Open Archive

Abstract

Bees are crucial for maintaining biodiversity by pollination of numerous plant species. The European honey bee, Apis mellifera, is of great importance not only for the honey they produce, but also as vital pollinators of agricultural and horticultural crops. The economical value of pollination has been estimated to be several billion dollars, and pollinator declines are a global biodiversity threat. Hence, honey bee health has great impact on the economy, food production and biodiversity worldwide. A broad spectrum of specific pathogens affect the honey bee colony including bacteria, viruses, microscopic fungi, and internal and external parasites. Some of these microorganisms and parasites are more harmful than others and infections/infestations may lead to colony collapse. Knowledge of the biology and epidemiology of these pathogens are needed for prevention of disease outbreak. The use of molecular methods has increased during recent years offering a selection of powerful tools for laboratories involved in honey bee disease diagnostics and research. Novel diagnostic techniques also allow for new approaches to honey bee pathology where specific and critical questions can be answered using modern molecular technology. This thesis focuses on molecular techniques and their application within honey bee pathology. Specific questions concerning five disease-causing agents all capable of inducing population depletion of honey bee colonies were addressed. The studied pathogens included two different bacterial species, (Melissococcus plutonius and Paenibacillus larvae) that cause serious disease in honey bee larvae, one virus (deformed wing virus, DWV) that causes deformity during pupal development and finally, two honey bee pathogenic microsporidia (Nosema ceranae and Nosema apis) that cause disease in adult bees. Resolving questions concerning prevalence and characterization of these pathogens using newly developed molecular methods has contributed to a better understanding of host-pathogen interactions and epidemiology in the honey bee system. Furthermore, the attained knowledge contributes to improved disease diagnostics and disease prevention in the beekeeping industry and expands the general field of honey bee epidemiology.