CONICET | Buscador de Institutos y Recursos Humanos

The Argentine ant(Linepithema humile) is a polydomous species (a colony occupies multiplespatially separated but socially connected nests). In the invasion range, polydomy is overexpressed, andsupercolonies with extensions of thousands of kilometers are formed. However,the real possible food distribution reaches up to 50 m from the food source. Ourobjective was (1) to study cuticular chemical profiles in ants of the same ordistant nests belonging to the same supercolony in the invasive range; and (2) toassess whether differences in the cuticular profiles of the nests could generatea limit or bias in food distribution within a supercolony. We expected thecuticular profiles to be more similar among nestmates than among non-nestmates,and consequently, we expected ants to preferentially perform trophallaxis withnestmates instead of non-nestmates. We worked with 3 nests of the Main EuropeanSupercolony, which were 300 to 1000 km apart from each other. Aggression testsconfirmed that all nests belonged to the same supercolony. Cuticle extractswere analyzed via Gas Chromatography-MassSpectrometry. Food distribution tests were performed confronting a fed donorwith five non-fed recipients for five minutes. Donor and recipients could beeither nestmates or non-nestmates, and all possible combinations were tested.Multiple behavioral variables were analyzed, for both donors and recipients. Resultsshowed that donors behave similarly when confronted either to nestmates ornon-nestmates recipients. Likewise, recipients respond in a similar way tonestmates and non-nestmates donors. Even though each nest we tested had a distinctivecuticular profile, the differences among them were not enough to trigger anybehavioral bias in workers in the framework of food distribution. We thusconclude that, when confronting L. humileworkers of different nests, no matter how far away those nests are, food willbe shared equally as long as they belong to the same supercolony.