Behavioural roles and task partitioning in the primitively eusocial wasp: Belonogaster juncea juncea (Hymenoptera:...

This study, conducted to examine the phenomenon of task partitioning in primitively eusocial insects, permitted us to record 39 behavioural items in colonies of the polistine wasp Belonogaster juncea juncea. Of these, 18 and 21 items were quantified using the instantaneous scanning technique in pre-emergence and post-emergence phase colonies, respectively. A principal components analysis showed that among these items, `absence from nest' (Afn), `cell inspection' (Is), `receive prey' (Rp), `malaxate prey' (Mp) for pre-emergence colonies, and `cell inspection' (Is), `self-grooming' (Sg), `egg-laying' (E1), `cell initiation' (CI), `move nesting material' (Mn), `receive prey' (Rp), `absence from nest' (Afn) for post-emergence colonies, are useful for describing the individual variability in a given colony. Nevertheless, a hierarchical cluster analysis based on all behavioural items quantified showed that five main behavioural roles could be defined viz: Foraging, building, feeding, inactivity and reproduction. The items, `land with prey' and `feed larva' were not correlated, showing that there is a slight task partitioning in regard to prey handling. In both pre- and post-emergence colonies, the same functions are performed but, the growing number of individuals and the greater availability of nesting material in old cells modified the composition of the items associated with reproductive behaviour at the post-emergence stage.