Honeybee Paralysis: Its Natural Spread and its Diminished Incidence in England and Wales

Abstract
In laboratory tests, paralysis virus spread best between individual adult bees when they were most crowded. Spread was probably by contact of their epidermal cytoplasm, because the virus was readily transmitted when topically applied to freshly broken cuticular hairs. A significant positive regression of paralysis outbreaks on diminishing numbers of colonies in England and Wales is interpreted as a result of relatively increased foraging activity by the remaining colonies which led to less contact between healthy and infected individuals within enzootically infected colonies.