The natural mechanism of suppression of Nosema apis Zander in enzootically infected colonies of the honey bee, Apis mellifera Linnaeus

Honey bees, artificially infected with Nosema apis Zander and introduced into an enzootically infected colony in summer when infection was naturally diminishing, were all infected and developed similar numbers of spores to those in naturally infected bees in spring when infection was high. This, and other evidence, suggests infection is not naturally suppressed by increased environmental temperature, but by reduction of infective fecal matter of the bees, which do not transmit infection to young individuals in summer.