Page 61 - University of Pretoria RESEARCH REVIEW 2018

Turning worker bees into false queens
Abdullahi A Yusuf, Department of Zoology and Entomology
Division of labour and task allocations are key features of organisation in social insects societies such as those of honey bees, ants and termites. Roles performed
in reproduction, defence, cleaning or taking care of the young, and other roles in ecosystem services like pollination, make studying and understanding eusocial insects and their behaviour both important and fascinating.
In honey bees, there is clear morphological and physiological differentiation between the workers and the queen, who uses chemical signals to control reproduction
in worker bees. However, in circumstances where there is a sudden loss of the queen, this hierarchy is
lost and workers have to restore
reproductive hegemony through the emergency rearing of a queen. During this process, several changes occur in the hive, which include the ability of workers to lay eggs and the appearance of false queens.
Dr Abdullahi Yusuf and researchers of the Social Insects Research Group (SIRG) have explored the possibility of transforming workers into false queens by the use of exogenous pheromone supplementation. Their study involved two native sub-species of honey bees, Apis mellifera scutellata (savannah honey bee), a sub-species in which laying workers are rarely produced, and A. m. capensis clones of the Cape honey bee that readily transform into laying workers and false queens.
They succeeded in transforming
both sub-species of adult honey bee workers into false queens through the
use of mobile honey bee pheromone carriers (bees carrying pheromones on their thoraces), and showed that these bees exhibit the behaviours and the physiology of queens. Another interesting finding was that workers can be manipulated into becoming false queens, irrespective of their genetic origin. They are now exploring the possibility of using pheromone supplementation in the management of social parasitism at its onset. The study, co-authored with Professors Robin Crewe and Christian Pirk, was published in 2018 in the Journal of Experimental Biology. The study also shows that the development of a mobile pheromone delivery system can be applied in other models in laboratory and field studies.
There are a number of concurrent research projects in SIRG, with published findings in 2018 including work on the molecular basis of pheromone production and regulation in honey bees, genes responsible for pheromone production, and the enzymes involved in downstream regulation of worker reproduction in social insects.
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