Effects of pollen and artificial diets on the hypopharyngeal glands of newly hatched bees (Apis mellifera L.)

The objectives of this experiment were to: 1. compare the hypopharyngeal gland development (by measuring the head weight) of caged newly hatched nurse bees fed on eight different pollen and artificial diets; and 2. examine the correlation between protein intake and head weight. The artificial diets: substitute 2; FeedBee (R); substitute 1; and protein substitute stimulated (in order) significantly higher head weight than the pollen diets: pure irradiated mixed pollen; redgum (Corymbia calophylla); redgum + soyflour protein isolate; and pollen supplement. Only artificial diets stimulated overall head weight of more than 10 mg and maintained head weight above the emergent head weight for the duration of the experiment. Substitute 2 and FeedBee (R) stimulated the highest head weight, followed by substitute 1 and pollen substitute, pollen supplement, mixed pollen and redgum + soyflour protein isolate, and redgum. The only diets to have positive correlation (p < 0.05) between the crude protein consumption and head weight were substitute 1 and pollen substitute.