Development of a system for commercial rearing of Japanese native bumblebees, Bombus hypocrita and B-ignitus (Hymenoptera: Apidae) with special reference to early detection of inferior colonies.

Worker and new-queen productivity in laboratory reared colonies of B. hypocrita and B. ignitus was influenced by both delays in oviposition and first worker emergence. In B. hypocrita, colonies with a period of 20 or less days before the first oviposition produced significantly more female castes than ones with 21 or more days. In B. ignitus, colonies with 10 or less days produced significantly more female castes than ones with 11 or more days. In both species, colonies with a longer period of more than 29 days before the first worker's emergence produced fewer female castes than normal colonies in which the first worker emerged in 28 or less days. These two parameters provide an effective and practical method for identifying normal bumblebee colonies in the early stages of commercial mass-production.