Rights and lefts of social behaviour (#393)
In agonistic interactions a preference to view the opponent with the
left eye before attacking has been shown in a number of vertebrate species. This
and other directional biases in populations appear to be beneficial in social
behaviour. For example, lateralized chicks form more stable social hierarchies
than do non-lateralized ones. Recent discovery of lateralized brain function in
invertebrate species has led to investigation of left-right asymmetries in
social bees (honeybees and stingless bees). As in honeybees, the more primitive
Australian stingless bees (3 species tested) show a clear preference to recall
olfactory memory when using their right antenna but only in the first hour or
so after training. By 5 hours after training, recall of the memory is no longer
possible with the right antenna but now the left antenna is used. Antennal
lateralities in social behaviour will be reported. Approaches and physical
contacts were scored in dyads of stingless bees (Tetragonula carbonaria): dyads in which both bees had only their
right antennae (RA+RA) made many more contacts than dyads in which both bees
had only their left antennae (LA+LA). In dyads of LA+RA, it was found,
unexpectedly, that the LA bee approached and often attacked (by biting) the RA bee
much more often than vice versa. The
low number of contacts in LA+LA dyads must be due to mutual avoidance, perhaps
due to release of a pheromone that inhibits contact. Using a right antenna
facilitates friendly social behaviour (e.g. proboscis extension and
trophyllaxis), which is appropriate between hive mates, whereas using a left
antenna leads to inappropriate social behaviour between hive mates. Via such
left-right asymmetries, intact bees (and other species) may compute behaviour
directed towards friend and foe.