INVESTIGADORES
ARENAS Andres
congresos y reuniones científicas
Título:
DELAYED AVOIDANCE OF PLANTS IN FORAGING L EAF- CUTTING ANTS IS TRIGGERED BY VOLATILES PRESENT IN THE NEST REFUSE CHAMBER
Autor/es:
A. ARENAS; F. ROCES
Reunión:
Encuentro; The 3rd CENTRAL EUROPEAN SEC TION MEETING of the INTERNATIONAL UNION FOR THE STUDY OF SOCIAL INSECTS; 2013
Resumen:
Decision making in foraging leaf-cutting ants is not simply the result
of the workers´ preferences, but is also influenced by the state of their
symbiotic fungus as an additional informational center. Foragers can avoid
certain plant species if they have been proven to be harmful for the fungus,
albeit harmless for themselves. In response to the deleterious effects on the
fungus, foragers interrupt harvesting of these leaves leading to delayed rejection,
a phenomenon that involves long-lasting avoidance learning and that initiates
soon after the introduction of the noxious substrate into the fungus garden. We
found evidence that avoidance response is mediated by the presence of the
substrate-related cues at the refuse chamber of the nest, where ants deposit
the waste. By exchanging the refuse chambers of subcolonies that foraged on
fungicide-infiltrated leaves and non-treated subcolonies, foragers from
non-treated groups were able to reject the leaves the other group experienced
as noxious. Moreover, the mere presence of inert-paper disks added with neutral
odors in the refuse chamber was enough to convey information about the unsuitability
of the substrate: foraging ants rejected those substrates smelling to the odors
that scented the refuse chamber. Interestingly, the same odors that induced
rejection when offered in the refused chamber turned out to be preferred if
they were initially added into the fungus garden. We suggest that leaf-cutting
ants decide to accept certain plants and reject others also based on local olfactory
information obtained within the nest environment.