Cumulative survival of worker bees, pooled for all colonies (n = 3) for reasons of clarity. Bees were fed pure casein, pure sucrose, and three protein sources (casein, aloe pollen and royal jelly) in three different protein:carbohydrate (P:C) ratios of 3:1, 1:1, and 1:3. The three protein sources are compared in A (casein), B (pollen) and C (royal jelly).