A. Dahbi et A. Lenoir, NEST SEPARATION AND THE DYNAMICS OF THE GESTALT ODOR IN THE POLYDOMOUS ANT CATAGLYPHIS-IBERICA (HYMENOPTERA, FORMICIDAE), Behavioral ecology and sociobiology, 42(5), 1998, pp. 349-355
In the polydomous ant species Cataglyphis iberica, nests belonging to
the same colony are completely separated during hibernation. In order
to examine whether this separation induces changes both in the hydroca
rbon profile and in recognition ability between adult nestmates, we se
parated groups of workers for several months under two different condi
tions: at hibernation temperature and at room temperature. At room tem
perature, recognition remained unchanged but separation led to longer
mutual antennations relative to non-separated controls. When half of a
colony was placed under hibernation conditions, antennal interactions
also increased in duration and a few aggressive interactions emerged
between separated ants. This aggressiveness never reached the intercol
onial level observed in this species. In both cases, the hydrocarbon p
rofiles showed differences between individuals after separation while
remaining homogeneous within each nest. This chemical modification may
induce the longer antennations observed. After separated groups were
reunited, individuals recovered their previous antennation pattern and
a convergence in hydrocarbon profiles was again observed. These concu
rrent observations suggest that hydrocarbons are transferred between n
estmates. In C. iberica, the formation of the colonial odor seems to f
ollow the ''Gestalt'' model which allows all satellite nests of a colo
ny to have a common colonial odor. In the field, temporary nest isolat
ion during hibernation may induce divergence between satellites. The r
ole of adult transport in connecting nests during the active season to
obtain an efficient Gestalt odor is discussed.