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Submitted to: Meeting Abstract
Publication Type: Abstract Only Publication Acceptance Date: 4/6/2011 Publication Date: N/A Citation: N/A Interpretive Summary: The red imported fire ant, S. invicta, is among the world’s 100 worst invasive alien species. In the United States this ant species infests more than 320 million acres in 13 southern tier states and Puerto Rico and are spreading northward. It is estimated to be responsible for almost $7 billion annually in damage repair, medical care, and control costs. The affected economic sectors are broad ranging and include households, electric service and communications, agriculture, schools and recreation areas. In the last decade S. invicta has changed from an invasive pest ant in the United States to a global problem, with infestations occurring in Australia, Taiwan, mainland China, Mexico and many Caribbean Island countries. Global commerce ensures that fire ants will be distributed to compatible habitats throughout the world. Thus, novel control methods are needed and could result from manipulation of the fire ant alarm pheromone to disrupt mating flights or to in some way disrupt alarm pheromone production that could interrupt the normal insularity of fire ant colonies to pathogens, parasites, and other intrusions. In the present study, Scientists of the Imported Fire Ant and Household Insect Unit at the Center for Medical, Agricultural and Veterinary Entomology, USDA, ARS, Gainesville, FL have explored the changes in the amount of alarm pheromone accumulated in the mandibular glands of workers, female and male alate sexuals, and queens from the time they eclose as adults to late in their lifespan. It was discovered that the pattern of alarm pheromone accumulation is different in the above distinct female castes and mating status. The results presented here could be lead to an understanding of how the alarm pheromone is used by fire ants in the various contexts of workers, female alates, and queens. This is the initial step in developing novel, non-insecticide methods for fire ant control based on the interference of alarm pheromones in colony defense, mating flights, and colony development. Technical Abstract: Alarm pheromones are an essential part of a complex of pheromone interactions that contribute to the maintenance of colony integrity and sociality in social insects. Recently, we identified 2-ethyl-3,6-dimethylpyrazine as an alarm pheromone component of the fire ant, Solenopsis invicta. We continued to explore the ontogeny of alarm pheromone production in workers, female and male alate sexuals, and queens. In workers, alarm pheromone production commenced in the mandibular glands of callow fire ant workers directly after eclosion, and rapidly increased to a maximum at the brood tender stage. Then, pheromone accumulation sharply declined with the oldest temporal caste, foraging workers. In female alates, the late pupal stage had detectable amounts of alarm pheromone and after eclosion reached a maximum when the female alates were mating flight ready. Workers and female sexuals have different patterns of alarm pheromone production. Workers have a uni-modal pattern, whereas female sexuals have a bi-modal pattern of alarm pheromone accumulation. Production and utilization rates are discussed. |
