4.2.1. What to sample?
All viruses described to date can be detected in adult bees (Table 2). This is logical, since adult bees are central to most of the virus transmission pathways (Fig. 1), due to their high mobility, contact rate and diverse contact network. This makes adult bees the most suitable single bee stage for detecting all viruses. Within adult bees, the gut is a major site of accumulation for most viruses (and many other pathogens), and is thus the most suitable single tissue type for sampling.