Observations on the development of queenless colonies of Bombus atratus (Hymenoptera, Apidae)

TLDR: The results show that the absence of a queen does not prevent the frequency of oviposition in Bombus atratus colonies, and among egg-laying workers, there was a higher frequency of mated than non- mated workers in both colonies.

Abstract: SUMMARYIn two queenless colonies of Bombus atratus maintained in the laboratory, the largest worker present became the dominant female (false queen) which mated and produced female offspring. In both colonies the frequency of oviposition increased with colony development, not only because of shorter intervals between egg laying by the false queens, but also because of the later appearance of other laying workers. These workers started to lay after the false queens had begun to lay unfertilized eggs. This change occurred on day 79 in one colony, and on day 58 in the other colony, and the first worker oviposition occurred on days 104 and 69, respectively. Among egg-laying workers, there was a higher frequency of mated than non- mated workers in both colonies. These workers showed a tendency to be among the largest in the colonies. All queens and about 31 % of the total worker population of each colony were produced by mated egg-laying workers. The results show that the absence of a queen does not prevent th...