Interactions among parasites, pathogens and pesticides in individual bees
Fundamental to determining the role of multiple factors on honeybee colony demise is an understanding of their impacts at an individual bee level, which will be the purpose of WP1. Only here can we test in detail the physiological and molecular basis of pathogen interaction under rigorously controlled conditions, to exclude confounding effects that frequently appear at colony level. Throughout these experiments the natural conditions of the hive will be simulated as much as possible, without sacrificing experimental control.
Two parasite-pathogen systems will be studied, one operating at brood level (Varroa & DWV) and one operating at adult bee level (Nosema & BQCV/IAPV) and in each case a further interaction of the entire system with sub-lethal pesticide doses will be investigated. The experimental material will be produced by varroa-free, virus-free colonies, manipulated at small cohort level, scored for biologically relevant parameters and sampled individually. These samples will then be subjected to extensive molecular analyses. The most significant subset of samples will be sent to WP3 where non-lethal effects of multiple factors at the level of the host transcriptome will be assessed to determine if and how the immune response of individual bees is affected by interacting diseases and environmental stressors.