Higher Essential Amino Acid and Crude Protein Contents in Pollen Accelerate the Oviposition and Colony Foundation of Bombus breviceps (Hymenoptera: Apidae)

SIMPLE SUMMARY: Bombus breviceps is an important native species of bumblebee in southern China. As a pollinator, it has the potential for domestication and commercial rearing. In this study, in order to identify the nutritional requirements for the egg-laying, hatching, and colony foundation stages, we selected three common local types of pollen, including camellia pollen, oilseed rape pollen, and apricot pollen, as well as mixtures of them, to feed B. breviceps queens to evaluate the reproductive performance, and feasibility of these pollens as a diet and the nutritional requirements. The results showed that the pollen with a higher essential amino acid content had advantages in laying time, the number of eggs laid, larval ejection, and the time of first worker emergence, while the pollen with a higher crude protein content had advantages in the time the colony took to reach ten workers. These results may guide the selection of feed in B. breviceps artificial feeding and help to explore the nutritional requirements in oviposition and the colony stage from the perspective of conventional pollen. ABSTRACT: Pollen is an important source of nutrition for bumblebees to survive, reproduce, and raise their offspring. To explore the nutritional requirements for the egg laying and hatching of queenright Bombus breviceps colonies, camellia pollen, oilseed rape pollen, apricot pollen, and mixtures of two or three types of pollen in equal proportions were used to feed the queens in this study. The results showed that the camellia pollen with a higher essential amino acid content was superior to the pollen with a lower essential amino acid content in the initial egg-laying time (p < 0.05), egg number (p < 0.05), larval ejection (p < 0.01), time of first worker emergence (p < 0.05), and the average weight of workers in the first batch (p < 0.01). It took less time for colonies under the camellia pollen and camellia–oilseed rape–apricot pollen mix treatments, both with a higher crude protein content, to reach ten workers in the colony (p < 0.01). On the contrary, the queens fed apricot pollen never laid an egg, and larvae fed oilseed rape pollen were all ejected—both pollens with a lower essential amino acid content. The results emphasize that the diet should be rationally allocated to meet the nutritional needs of local bumblebees at various stages when guiding them to lay eggs, hatch, and develop a colony.