Together we conquer! Intraspecific aggression in the little fire ant Wasmannia auropunctata

Invasive species are known to out-compete native species and successfully expand their range. In many invasive species a decrease in intraspecific aggression due to relatedness among individuals aids in their expansion. Invasive ants are among the most important pests worldwide. In many cases, such as the Argentinean ant Linepithema humile their success is due to lack of intraspecific aggression. The little fire ant Wasmannia auropunctata is considered a worldwide pest and is an important invasive species in Puerto Rico. In this study we evaluated intraspecific aggression in the little fire ant. We expected that the little fire ant will show little or no intraspecific aggression between colonies. We tested thirteen colonies by introducing an individual from a different colony and observed their behavior. This behavior was ranked from 0 to 4, where 0 is ignoring and 4 is prolongated aggression, stinging and biting. Our data suggests that there is no significant intraspecific aggression between W. auropunctata from different colonies. The results of this study should expand our understanding in the evolution and success of the little fire ant as an invasive species.