Temporal changes in Varroa destructor fertility and haplotype in Brazil

The relationship between fertility and haplotype was studied in Varroa destructor mites sampled from colonies of A. mellifera carnica and Africanized Honeybees ( Apis mellifera) in Germany and Brazil respectively. Both in Germany and in Brazil, only the V. destructor Korea haplotype was found, though the Japan-Thailand haplotype was formerly thought to have been more abundant in Brazil. The fertility of Varroa mites in Brazil has increased since 1998 and is currently ( 2001) at European levels. Temporal changes in mite fertility and haplotype are not fully congruent.

A sting in the spit: widespread cross-infection of multiple RNA viruses across wild and managed bees

Declining populations of bee pollinators are a cause of concern, with major repercussions for biodiversity loss and food security. RNA viruses associated with honeybees represent a potential threat to other insect pollinators, but the extent of this threat is poorly understood. This study aims to attain a detailed understanding of the current and ongoing risk of emerging infectious disease (EID) transmission between managed and wild pollinator species across a wide range of RNA viruses. Within a structured large-scale national survey across 26 independent sites, we quantify the prevalence and pathogen loads of multiple RNA viruses in co-occurring managed honeybee (Apis mellifera) and wild bumblebee (Bombus spp.) populations. We then construct models that compare virus prevalence between wild and managed pollinators. Multiple RNA viruses associated with honeybees are widespread in sympatric wild bumblebee populations. Virus prevalence in honeybees is a significant predictor of virus prevalence in bumblebees, but we remain cautious in speculating over the principle direction of pathogen transmission. We demonstrate species-specific differences in prevalence, indicating significant variation in disease susceptibility or tolerance. Pathogen loads within individual bumblebees may be high and in the case of at least one RNA virus, prevalence is higher in wild bumblebees than in managed honeybee populations. Our findings indicate widespread transmission of RNA viruses between managed and wild bee pollinators, pointing to an interconnected network of potential disease pressures within and among pollinator species. In the context of the biodiversity crisis, our study emphasizes the importance of targeting a wide range of pathogens and defining host associations when considering potential drivers of population decline.

Research strategies to improve honeybee health in Europe

Understanding the fundaments of colony losses and improving the status of colony health will require cross-cutting research initiatives including honeybee pathology, chemistry, genetics and apicultural extension. The 7th framework of the European Union requested research to empirically and experimentally fill knowledge gaps on honeybee pests and diseases, including 'Colony Collapse Disorder' and the impact of parasites, pathogens and pesticides on honeybee mortality. The interactions among these drivers of colony loss will be studied in different European regions, using experimental model systems including selected parasites (e. g. Nosema and Varroa mites), viruses (Deformed Wing Virus, Black Queen Cell Virus, Israeli Acute Paralysis Virus) and model pesticides (thiacloprid, tau-fluvalinate). Transcriptome analyses will be used to explore host-pathogen-pesticide interactions and identify novel genes for disease resistance. Special attention will be given to sublethal and chronic exposure to pesticides and will screen how apicultural practices affect colony health. Novel diagnostic screening methods and sustainable concepts for disease prevention will be developed resulting in new treatments and selection tools for resistant stock. Research initiatives will be linked to various national and international ongoing European, North-and South-American colony health monitoring and research programs, to ensure a global transfer of results to apicultural practice in the world community of beekeepers.