Phorid flies in the genus Pseudacteon lay their eggs in the bodies of fire ant workers. Eventually the fly larva will move into the ant's head, where it will consume the contents, causing decapitation of the fire ant, hence the popular name "decapitating" flies.
Pseudacteon phorid flies are natural enemies of Solenopsis fire ants in their native habitat of South America and help keep their populations low. These flies only kill 2-3% of fire ants in a colony, but they make fire ants less competitive by changing fire ant behavior. They also cause stress to the fire ant colony, which may leave fire ants more susceptible to pesticides, other natural enemies, disease, or environmental factors.
Several fly species have been released in fire ant-infested areas in the United States. However, it is still too early to tell whether phorids will affect fire ant populations. It's important to note that phorids will not eradicate fire ants in the United States, but the ultimate goal is to create an ecological balance between fire ant and native ant populations.
By introducing biological controls, we give native ant species a better chance against the highly aggressive fire ants. To see which Pseudacteon species have been released in the United States, use the interactive map linked on the page Geographic Distribution of Fire Ants.
Related Content
- Natural Enemies of Fire Ants
- Are Pseudacteon phorid flies (decapitating flies) harmful?
- Will Pseudacteon phorid flies sting or bite?
- What happens when the Pseudacteon phorid flies run out of fire ants to eat?
- VIDEO: Decapitating Flies Attacking Fire Ants
Find more information about fire ants in eXtension's Imported Fire Ant Resource Area.
