Nest emigration tasks of the worker Asian needle ant, Pachycondyla chinensis (Emery) as identified in a laboratory study

Nest emigration is integral to the survival and propagation of an ant colony.  Colonies constantly move due to nest disturbances, climate fluctuations, and resource availability.  During nest emigration an ant colony may display different behaviors to complete the task including chemical trail following, tandem running, or physical adult transport.  The invasive Asian needle ant, Pachycondyla chinensis (Emery) employs adult transport to complete nest emigration.  In a preliminary laboratory study, I observed that in subsets of P. chinensis colonies containing 200 worker ants a mean of 39.2 carrying events occurred in 90 minutes during nest emigration when prompted by physical disturbance.  However, task allocation during the nest emigration was not investigated.  Investigation of the tasks carried out by P. chinensis during emigration can elucidate whether or not specific ants participate as carriers or if carrying is a non-specific behavior conducted by all ants.  In the current study, task allocation of worker ants was observed and recorded.  Individual ants were marked with paint and an ethogram describing carrying behavior and the roles of individual ants during emigration are described for the first time.