Behavioral interactions between the velvety tree ant Liometopum occidentale (Hymenoptera: Formicidae) and phorid flies (Diptera: Phoridae)

Phorid flies in the genus Pseudacteon are parasitoids of ants that are capable of decapitating their host during development and have been used as biological control agents for imported fire ants. In California, little is known about the effect of the native phorid fly Pseudacteon californiensis on populations of its native ant host the Velvety Tree Ant, Liometopum occidentale. This system is native to Southern California, occupying precious habitats that have been in decline due to human development, changing weather patterns, and fierce competition from invasive species. To further understand the ecological significance and behavior of this system, we examined the effect of this parasitoid fly on foraging behavior in ants, observed and quantified behavioral displays exhibited by ants in the presence of phorid flies, and assessed the role of ant pheromones in host location by phorid flies.