Research carried out in Australia sheds new light on the complexity of communication between ants by discovering that these insects not only collect information through their antennae, but also use them to transmit social signals. The study focuses on the use and function of the hydrocarbon cuticular layer that lines the body of ants.
The authors of this research, carried out at the University of Melbourne, claim that the antennae of ants (Iridomyrmex purpureus) are a bidirectional communication device, not just a receiver.
They came to this conclusion after analyzing the behavior and surface chemistry of hundreds of ants to examine how they interacted. The key point of the study was the use and function of cuticular hydrocarbons (HC), a layer of accumulated wax that covers the body of ants and also of other insects, such as bees, wasps, flies or beetles.
HCs are a group of multipurpose chemical compounds that not only protect insects from dehydration, but are also part of their communication toolkit. Ants use these chemicals, for example, to identify whether the other is friend or foe.
When the HCs were removed only from the ants’ antennae during the experiments, their opponents were no longer able to recognize the identity of the colony from which the manipulated ants came. This fact indicates that the HC of the antennas provide information about the nest to which the ants belong.
As one of the authors of the study, Qike Wang, explains, the antennae of ants are their main sensory organs, but until now, it was not known that they could also be used to send information.
More than 125 years ago, the famous entomologist Auguste Forel completely removed the antennae of four species of ants and joined them together. Instead of fighting, they huddled together in a totally unnatural and peaceful way. According to Wang, Forel’s experiment tells us about antennas as a tool for receiving chemical signals, but current research suggests they are also a source of chemical signals.
The authors also found that the profiles of the studied cuticular hydrocarbons were different depending on the part of the body they corresponded to, which goes against the conventional belief that the HCs in different parts of the ant body have the same profiles.
The cuticular oil profiles of workers and alates varied in different parts of the body. Workers paid more attention to the antennae of non-mates and to the legs of workers. They also responded much less aggressively to non-nestmate workers if the HCs on their opponents’ antennae were removed without a solvent.
Source: University of Melbourne and environmental hygiene