The measurement and interrelationships of infections with Nosema apis and Malpighamoeba mellificae of honey-bee populations

The numbers of spores of Nosema apis or cysts of Malpighamoeba mellificae, in samples of honey bees, (Apis mellifera) were correlated with the percentage of bees infected. Colonies infected with both parasites were more than expected by change and contained more bees infected with N. apis than usually occur in colonies with N. apis alone. M. mellificae multiplies less than N. apis in individual bees and does not cause obvious sickness.