In pursuit of the ultimate pollen substitute (insect larvae) for honey bee (Apis mellifera) feed

Abstract

Finding a pollen substitute for honey bees that is nutritionally adequate and affordable is a scientific and practical challenge. We attempted a new rational approach and tried to exploit honey bees’ natural cannibalistic behavior. We tested processed insect larvae as a food source that is nutritionally similar to bee brood, and which can easily be produced on a large scale. In cage experiments, monitoring bee mortality, food consumption and changes in bee body parts’ weights showed that flour obtained by grinding dried yellow mealworm larvae has the potential to become an excellent component for pollen substitution. Bees from the cage group fed Tenebrio molitor patties (TG) demonstrated overall best results in comparison to sugar patties fed bee group (CG), yeast patties fed bee group (YG) and pollen patties fed bee group (PG). They did not lose weight as rapidly as the CG, did not defecate inside cages as the YG, nor show increased mortality as the PG. At the same time, TG consumed less food (mean 13.7 g/cage) than CG (16.8 g/cage), YG (20.4 g/cage) and PG (23.9 g/cage) within the period of 28 days. Bees’ gut increase in weight was lowest in the CG, followed by TG and PG and was the highest in the YG which resulted in diarrhea after 14 days. Bees from TG did not lag behind other bees in head, thorax and abdomen weight after 28 days. We demonstrated that processed yellow mealworm larvae (T. molitor) can be used as an ingredient for honey bee feed.