Worker reduction affects investment in reproduction in eusocial wasps: a case of task flexibility?

MELO ROMINA; MASCIOCCHI MAITÉ; CORLEY JUAN CARLOS

Congreso; XXXVIII Encuentro de Etología, III Encuentro de Biología del Comportamiento del Cono Sur; 2021

Division of labour with workertask specialization in social insects, is a factor that has determined theirsuccess, because it allows optimizing the invested workforce. In a colony,sub-castes of workers carry out different tasks, such as nest building,defence, food collection, feeding, and  nursingor breeding care in parallel. Flexibility in allocation of individuals todifferent tasks allow the colony to respond to external changes in theenvironment and internal perturbation, such as that arising from differentialmortality of individuals undertaking a given task. We evaluated experimentallywhether the removal of workers -in different proportions- affected the reproduction,measured as number and quality of gynes, in colonies of Vespula germanica..Also, we analysed some colony tasks, like food collection, defence, andhygiene, that could affect investment in gynes. The number of gynes producedwas affected by worker removal, but not their weight. Similarly, worker removalnegatively affected the amount of food collected but did not affect the numberof workers cleaning and guarding the nest. These results could be suggestingthat, in response to the decrease in food entering the nest, the colony couldbe producing fewer gynes to maintain their quality. Also, a flexibilityallocation of individuals to different tasks within the colony in response to thedecrease in the overall number of workers could be happening. Understanding theallocation of tasks within the worker subcaste could provide a better knowledgeof the mechanisms that promote the success of invasive social insects