There are over 1100 species of Pheidole genus ants, and most individual ants belong to either the worker or soldier caste. In only eight of the Pheidole species, some individuals can belong to a “supersoldier” subcaste instead, and these ants fight off predatory army ant species and bar their way by blocking off the entrances to the nest using their over-sized heads. Now, scientists have managed to create supersoldiers in other species by reactivating ancestral genes.
The international team of scientists, led by Dr Ehab Abouheif of the Department of Biology at McGill University in Montreal, Canada, looked at the genomes of two ant species that produce supersoldiers. They identified the genetics behind the supersoldier caste and were able to activate the genes by treating ant larvae with methoprene, a growth hormone. As expected, the ant larvae became supersoldiers.
They then treated in the same way larvae of Pheidole morrisi, an ant species which lives in New York and that does not normally produce supersoldiers, but which lead author, Dr Abouheif, had previously noted produced large-headed ants resembling supersoldiers on rare occasions. The treated larvae grew to become large headed and jawed ants resembling supersoldiers. The same effect was produced in two other Pheilode species, which are not known to produce supersoldiers.