ARBEITSGEMEINSCHAFT DER INSTITUTE FÜR ... - HAL - INRIA

SUMMARY
Trophallaxis of worker honey bees in smafl groups and colonies
Colonies of eusocial insects are often characterized by dominance hierarchies.
In colonies of the honey bee (Apis mellifera L.) the dominant individual is the
queen whereas the workers are thought to be a subordinate caste (W ILSO rr,
1975).
KoRST &
VELTHU IS (1982), however, have shown that dominance hierarchies
among workers (A.m. capensis ESCH.) exist under queenless conditions.
Dominant workers develop their ovaries faster, produce more eggs, and more
9-Oxo-2-decenoic acid, the main component of the queen substance. Therefore
these dominant bees have a greater genetic fitness than subordinates (MORITZ &
HILLESHEIM , 1985). These characters are correlated with trophallactic behaviour
in laboratory experiments, i.e. subordinate workers in a small group (3 standard
bees and 1 test bee of the same age - 2 days old) offer food to the standard bees
while dominant workers are fed.
Here we studied whether the feeding hierarchy under laboratory conditions
reflects a general trophallactic behaviour which can also be found in colonies.
Trophallaxis of workers of 7 different lines was tested in small groups in the
laboratory test. The ratio of dominant feeding acts to the total of observed feeding
acts of the test bee was determined and the degree of dominance was evaluated
according to MORIT Z & Htt,LesHEtM (1985). Workers of the same lines were then
tested in one queenright observation hive. In contrast to the tests in small groups,
test bees were exposed to the socially complex and environmentally more heterogeneous
conditions in the colony. Nevertheless the genotypic correlation between
the trophallactic behaviour in the small group and in the hive resulted in r 0.82
=
(p 0.05).
=
It could be shown that besides the age effect (FREE, 1957), there were also
genetic factors determining trophallactic behaviour of worker bees in queenright
colonies. Genetic variance might be an additional factor regulating division of
labour in honey bee colonies in general.
Acknowledgerrrent : Financial support was given by the Deutsche Forschungsgemeinsch.tf:
(grant KO 400/6-1).