Conservationists worry that S. invicta‘s evolution towards multiple-queen colonies will be disastrous for native insects and spiders. Building dense colonies and out-competing other species, the multiple-queen form of S. invicta seems to do more damage than the single-queen form. What can we do to protect habitats and native species from S. invicta? Conservationists hope that the knowledge we gain by studying the evolution of this ant will help us control them in ecologically sound ways — something we have not managed to do in the past.
In the 1960s, the United States government waged a literal war on fire ants. Bombers from World War II were used to dump ant poison on colonies. However, many scientists suspect that this approach inadvertently helped fire ants and harmed native species. The poison used to bombard colonies was powerful and non-specific — it killed native ants and fire ants alike. But unlike many native species, fire ants are well-adapted to recovering from catastrophe — in South America, fire ants live in flood-prone areas and have evolved to quickly repopulate an area after natural disasters, or a deluge of ant poison! In this case, by using ant poison and killing off native species, we may have simply provided an opportunity for the fire ants to come back with a vengeance, without competition.
We don’t want to make the same mistake twice. Instead of taking an “atomic bomb” approach — like dumping lots of poison into the environment — we’d like to use a “silver bullet” — a tool that would control just the fire ants, without harming other species. Discovering Gp-9 may help scientists do just that. Using their knowledge of Gp-9 and other genes involved in ant communication, scientists might be able to design synthetic scents that would disrupt communication in fire ant colonies, disabling them. These scents might even cause ants in a colony to fight each other — causing a colony to “self-destruct,” without the need for powerful poisons. By studying the evolution of fire ants in their native South America and after their invasion of the U.S., scientists have gained an understanding of the evolutionary, genetic, and ecological reasons that colonies spread — an understanding that may help us manage this pest, as well as future invaders.