Seed Selection by the Red Imported Fire Ant (Hymenoptera: Formicidae) in the Laboratory

Abstract

Ninety–sixspecies and varieties of seeds in 28 families were presented to laboratory colonies of Solenopsis invicta Buren. Small seeds were moved and subsequently damaged more often than large seeds. Although generally more resistant to damage, some species with large seeds such as com, Zea mays L., were susceptible to S. invicta damage. Seed coats protected some seed species from ant damage. Presence of repellent and attractant surface chemical swas also demonstrated for some seeds. Although chemicals could be extracted from seeds that could be considered attractive, some seeds appeared to be protected from S. invicta predation by repellents (predation means the seed is damaged so extensively that it can no longer germinate). Many species of seeds were susceptible to some degree of S. invicta predation, and most were transported to new locations. We also soaked seeds, which in general increased their susceptibility to predation, although seed removal was reduced. Seeds that were beginning to germinate were difficult to characterize: some germinated seeds were more susceptible to predation, but other germinated seeds were less susceptible to predation. Of resistant and susceptible seeds, Fabaceae seeds were most resistant and Labiatae seeds were most susceptible to S. invicta movement and damage. Seeds may play an important role as a food resource for S. invicta , and, as a result, S. invicta may be serious seed predators and competitors of animals for which seeds represent an important resource.