ALLOETHIC EFFICIENCY IN THE PATROLLING NETWORKS OF A POLYMORPHIC ANT,TAPINOMA-NIGERRIMUM (HYMENOPTERA, FORMICIDAE)

This study analyses some aspects of the role of alloethism in the netw orks of patrolling workers of a polymorphic ant species (Tapinoma nige rrimum) in the nest surroundings. We focus on the analysis of movement and distribution patterns of different-sized individuals, and their r elationship to the potential transfer of information between each othe r via contacts during patrolling activities. Our results suggest that small workers are potentially more efficient in these kind of activiti es (information discovery and transfer), because they contact each oth er more than could be expected by a random process based on their prop ortions and, also, because their deduced energetic expenditure per uni t of information found or transferred is lower than that of large work ers, These differences in the contacts between patrolling ants for sma ll and large workers cannot be explained by their movement patterns (v elocity, time spend in movement, turning angles), which do not differ between both groups but, rather, seem to be a consequence of their res ulting distribution patterns (overdispersed for large ants and random for small ones).