Despite considerable evidence of keystone species in biotic communities, the ecological factors that determine how and why a species functions as a keystone are not well known, particularly in terrestrial communities. The Red Imported Fire Ant (Solenopsis invicta Buren) is an abundant predator with strong and pervasive effects in agroecosystems throughout the southeastern United States. Recent field experiments in several agricultural systems, however, suggest that the community-level effects of fire ants vary in different crops, possibly in relation to the presence and abundance of honeydew-producing Homopterans. Because insect honeydew increases fire ant abundance and aggression on plants, the presence of honeydew-producing insects may intensify the effects of fire ants as predators of other canopy arthropods. Currently, there is no abundant Homopteran pest of soybean in the Southeast and fire ants only weakly affect the arthropod community in the soybean canopy. In anticipation of the southward spread of the Soybean Aphid (Aphis glycines Matsumura) into the range of fire ants, we conducted artificial honeydew experiments in the field and greenhouse to test whether the community-level effects of fire ants will change in response to the aphid in soybean agroecosystems. We predict that the application of artificial honeydew (a substitution for the soybean aphid) will increase the abundance of fire ants on soybean plants, thereby intensifying the community-level effect of fire ants as predators of herbivores and other natural enemies.