Type of Thesis
Ecology and Evolutionary Biology
Dr. Michael Breed
Dr. Pieter Johnson
Dr. J. Colleen Berry
Societies require cooperation among individuals to be successful. This is especially true in eusocial insect colonies such as the western honeybee Apis mellifera. The tasks that individuals perform are among the most important reasons for the cooperation that allows for division of labor. Switching between tasks such as guarding and fanning is an important factor in this division of labor. However, switching does have both benefits and costs associated with it that make the level of plasticity in switching very important. In order to better understand the plasticity of task switching we must also find the mechanisms that regulate and allow for it. In an attempt to understand this, I have designed three hypotheses. These hypotheses involved assessing fanner persistence, measuring guard and fanner task switching, and testing a possible mechanism that controls task switching. The results of testing these three hypotheses showed us that fanner persistence is incredibly low within a single day; this is very similar to research on day to day fanner persistence. Guards and fanners are both likely to switch tasks but overall guarding is more stable than fanning. It is still unclear what mechanism controls this preference for guarding. A fanner removal experiment showed that task switching is likely not based on worker replacement but rather a different mechanism. These results show us that task switching is incredibly plastic and that certain tasks may be preferred by workers. Although a mechanism that allows for this favoring is not understood, I suspect that the differential energy cost of tasks may play a role. These results are important in discovering the plasticity of task switching and the mechanisms that control it.
Ternest, John J., "Task Partitioning: Mechanisms, Benefits, and Costs of Plasticity in Western Honeybee (Apis mellifera) Labor" (2016). Undergraduate Honors Theses. 1118.