HONEY BEE VIRUSES

Three known viruses infect honey-bees. Two can cause paralysis and early death of adult bees but only one, chronic bee-paralysis virus, is known to do so in nature. This virus, which has anisometric particles resembling prolate spheroids, is a common cause of sickness of adult bees, but it is very widely distributed as an inapparent infection, especially of the salivary glands of adults, and is probably transmitted when bees feed each other. Susceptibility to paralysis seems determined mainly by hereditary factors. The second virus, acute bee-paralysis virus, which has isometric particles, has been associated with disease only in the laboratory, but it also is very common as an inapparent infection of adult bees. The third virus, which has particles resembling those of acute bee-paralysis virus, causes a disease, sacbrood, of larvae. It can also multiply in adult bees, when it causes no overt symptoms, but accumulates in their hypopharyngeal glands, which secrete food for larvae.