Competition between ant species: outcome controlled by parasitic flies.

Experimental evidence demonstrates that the parasitic phorid fly Apocephalus shifts the competitive balance between the ant species Pheidole dentata and Solenopsis texana by interfering with the defensive behavior of Pheidole dentata major workers (soldiers). This represents one of the first examples of a parasite affecting competitive interactions anmong terrestrial animals in natural communities. Similar complex interactions are probably common in many ant communities.