Behavioral and Biochemical Variation in the Fire Ant, Solenopsis invicta

The fire ant, Solenopsis invicta Buren, was accidentally introduced into the southern United States in the 1930s from South America. It is most probable that the United States S. invicta population is derived from a limited introduced gene pool, which may dampen within-colony and colony to colony variation. One of the most important elements of this strategy is the homing and subsequent trail formation to the food source. The majority of competition for food resources comes from other fire ant colonies and other ant species. A second pheromone system inhibits dealation and oogenesis in fire ant female alates. The pheromone is produced by the colony queen and acts directly on the alates. The chapter looks specifically at the behavioral and chemical variability of recognition in fire ants although some statements will apply to nestmate recognition in general. Investigation of changes in colony hydrocarbon patterns with time showed that cuticular hydrocarbon patterns change with time.