Supersoldiers

6 Jan 2011 - Ants can be programmed to become "supersoldiers", according to an international team of researchers. All ant colonies are made up of insects of different "castes", including soldiers and workers. This team worked out how to "trick" developing ant larvae to turn into a rare and unusual supersoldier caste.

The breakthrough, the researchers say, reveals that hidden traits could be unlocked in many species.
 Dr Ehab Abouheif from McGill University in Montreal led the team, which found that treating ant larvae with a hormone at a very specific time during their development turned those ants into the giant supersoldiers. The scientists managed to achieve this in two ant species that do not "naturally" have the supersoldier caste as part of their colony. Dr Abouheif and his team studied Pheidole ants - a large group of more than 1,000 related species. Of those, there are just eight that have a so-called supersoldiers, which help protect the colony by blocking the entrance from invaders using their oversized heads.
The idea of attempting to "programme" developing ants to become these giant soldiers was triggered when Dr Abouheif noticed that another common Pheidole ant species, which does not have any supersoldiers in its colony, had a few strangely big-headed colony members. "We were collecting [the ants] on Long Island, New York, and we noticed some monstrous-looking soldiers," Dr Abouheif said. The apparently mutant ants looked just like the rare supersoldier caste of related species, so the scientists set out to find out what had caused them to take that form. "We understand a lot about how these different castes are produced during development of the ant larvae," said Dr Abouheif. Supersoldiers are much larger than worker ants of the same species

When a queen lays eggs, he explained, each egg can develop into a different caste depending on the environment it is in - the temperature it develops at and the nutrition it receives. But the key to "switching" into a specific cast is controlled to a large extent by one chemical inside the eggs, which is called juvenile hormone. "So if you treat any species at the right time in development, just with a hormone, you can induce the development of the supersoldier," explained Dr Abouheif.