Data from: Social transmission of information about a mutualist via trophallaxis in ant colonies

Partner discrimination is crucial in mutualistic interactions between organisms to counteract cheating by the partner. Trophobiosis between ants and aphids is a model system of such mutualistic interaction. To establish and maintain the mutualistic association, ants need to correctly discriminate mutualistic aphids. However, the mechanism by which ants recognize aphids as their partners is poorly understood, despite its ecological and evolutionary importance. Here, we show for the first time the evidence that interaction with nest-mates that have tended aphids (Aphis craccivora) allows ants (Tetramorium tsushimae) to learn to recognize the aphid species as their partner. When ants had previously tended aphids, they moderated their aggressiveness towards aphids. More importantly, ants that had interacted with aphid-experienced nest-mates also reduced their aggressiveness towards aphids, even though they had never directly experienced them, indicating that aphid information was transmitted from aphid-experienced ants to inexperienced ants. Furthermore, inhibition of mouth-to-mouth contact (trophallaxis) from aphid-experienced ants to inexperienced ants by providing the inexperienced ants with artificial honeydew solution caused the inexperienced ants to become aggressive towards aphids. These results, with further supporting data, strongly suggest that ants transfer information on their mutualists during trophallactic interactions.

在生物间的互利共生互作中，伴侣识别（partner discrimination）对于抵御合作伙伴的欺骗行为至关重要。蚂蚁与蚜虫间的营养共生（trophobiosis）便是这类互利互作的经典模型系统。为建立并维持这种互利共生关系，蚂蚁需要准确识别互利性蚜虫。尽管该过程具有重要的生态学与进化学意义，但蚂蚁识别蚜虫作为共生伙伴的具体机制仍鲜为人知。
本研究首次提供实验证据：与照料过菜豆蚜（Aphis craccivora）的同巢伙伴互动，可使东京铺道蚁（Tetramorium tsushimae）学会识别该蚜虫物种作为其共生伙伴。当蚂蚁此前亲自照料过蚜虫时，它们对蚜虫的攻击性会有所减弱。更为关键的是，即便从未直接接触过蚜虫，与有蚜虫照料经验的同巢伙伴互动过的蚂蚁，同样会降低对蚜虫的攻击性，这表明蚜虫相关信息可从有经验的蚂蚁传递给无经验的个体。此外，通过向无经验蚂蚁提供人工蜜露溶液，阻断有蚜虫照料经验的蚂蚁与无经验蚂蚁间的口对口交哺（trophallaxis）行为，会导致无经验蚂蚁对蚜虫表现出攻击性。结合额外的辅助数据，上述结果有力表明：蚂蚁可在交哺互动过程中传递其共生伙伴的相关信息。