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In colonies of independent-founding wasps, social organization is characterized by a division of labor wherein the most dominant female (the queen) spends more time on the nest comb during its development, while the subordinates (workers) perform most of the foraging. The present study aimed at describing how tasks are assigned among the members of colonies of Mischocyttarus cassununga (Von Ihering) during the post-emergence phase. For this, we daily tape recorded the behavioral repertoire of thirteen colonies in the field, later analyzing the results of each colonial subphase with Statistic analysis (Principal Component Analysis, Clustering Analysis and ANOVA - Tukey-Kramer t-test p<0.05). Our results showed that the assignment of tasks in M. cassununga generally reflects the dominance hierarchy. Despite of the behavioral flexibility of basal eusocial wasps, it was possible to identify different groups of subordinate females (workers) in the colony. The division of labor during the pre-male subphase was delineated with four defined groups whereas the post-male subphase with three groups. Pre-male: G1 - a dominant group of reproductive females, G2 - a group of higher hierarchically subordinate females (these can sometimes perform tasks very similar to the queens), G3 - a subordinate group of forager females, and G4 - a subordinate group of inactive and principally young wasps. Post-male: G1, G2 and G3 (similar groups during pre-male subphase, but without G4. We think these analyses suggest a novel view of the importance of the behavioral repertoire of higher hierarchically subordinate females in wasp nests, at least in the genus Mischocyttarus.

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The genusMischocyttaruscomprises 245 species of neotropical basal eusocial wasps. They form small colonies (rarely more than few tens of individuals); castes are morphologically undifferentiated and determined behaviorally by agonistic interactions. The aim of this study was to verify the effects of the experimental disruption of social hierarchy on foraging activity ofMischocyttarus cerberus styx. We observed six colonies in postemergence phase and recorded data on the foraging activity under two experimental conditions: (1) removal of lower-ranked females and (2) removal of higher ranked females, except the queen. Our results showed that the removal of higher-ranked females had higher effect on the number of foraging trips ofM. cerberus styxthan the removal of lower-ranked females (the number of foraging trips/hour decreased by 66.4% and 32.7%, resp.). Such results are likely due to the social organization of this species and the presence of a distinct class of females, which in this study were regarded as intermediates. Our data also showed that, irrespective of the hierarchical status of the females, the removal of two or three individuals affected significantly the number of foraging trips in this species.