Plant farming by ants ($)

Farming mutualisms, in which an organism benefits from another to promote growth, have evolved in many lineages. In particular, symbioses between plants and ants are mostly defensive mutualisms. In this paper, Chomicki and Renner describe the obligate mutualism observed between epiphytes in the genus Squamellaria and Philidris nagasau ants. They observed that P. nagasau ants disperse Squamellaria seeds inhabited by these specialist ants, and take care of the seedlings by fertilizing them actively, showing evidence for the first instance of obligate farming of plants by ants. Furthermore, they show that some traits of these plants and their specialist ants have coevolved around 3 million years. (Summary by Gaby Auge) Nature Plants, doi:10.1038/nplants.2016.181