A species of ant in Fiji survives by farming six plant species. The ants nurture seedlings and then live in the cavities of the plants.
Guillaume Chomicki and Susanne Renner of the University of Munich in Germany found that Philidris nagasau ants carry seeds of six species of Squamellaria plant and insert them into cracks in trees, where they germinate (pictured). The ants also fertilize the seeds with their waste, and are only found living near these plants.
Although ants are known to farm fungi, this is the first time they have been found to plant seeds and actively cultivate them. Examining the family trees of relatives of these ants and plants suggests that this mutually dependent relationship evolved around 3 million years ago.
Nature Plants http://dx.doi.org/10.1038/nplants.2016.181 (2016)