|Vander Meer, Robert - Bob|
Submitted to: Journal of Chemical Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/31/2010
Publication Date: 6/15/2010
Citation: Suckling, D.M., Stringer, L.D., Bunn, B., El-Sayed, A.M., Vander Meer, R.K. 2010. Trail pheromone disruption of red imported fire ant. Journal of Chemical Ecology. 36:744-750. Interpretive Summary: Imported fire ants cause over 6 billion dollars in annual control and damage costs in the United States and they are becoming a world-wide invasive pest ant. They infest Australia, Taiwan, China, Mexico and many Caribbean Island countries. Fire ant control relies on toxic drenches or baits that are bad for the environment and also affect non-target ant species. There is a need for biologically-based control methods, such as use of fire ant pheromones. To date suggested uses of pheromones for pest ant control have focused on making baits better. However, scientists at the Center for Medical, Agricultural and Veterinary Entomology, USDA, ARS, Gainesville, Florida USA, and the New Zealand Institute for Plant & Food Research Limited, Christchurch, New Zealand, collaborated to evaluate the effects of large amounts of the fire ant recruitment orientation pheromone, Z,E-'-farnesene, on the ability of fire ants to maintain recruitment trails to food resources. We found that the Z,E-'-farnesene effectively stopped orientation to the food source. Disrupting fire ant recruitment to resources on a large scale is expected to have negative effects on resource collection, colony size, colony migration, and other effects yet to be determined. Recently Argentine ant trails were disrupted for up to two weeks in the field using a microencapsulated trail pheromone. Further research is needed to establish the long-term effects and control potential for trail disruption in S. invicta.
Technical Abstract: The fire ant, Solenopsis invicta, is one of the most aggressive and invasive species in the world but toxic bait systems affect non-target ant species and can not be used in sensitive ecosystems. The fire ant uses recruitment pheromones to organize the retrieval of food resources back to the colony. Z,E-a-farnesene is responsible for the orientation of workers along trails. We demonstrated disruption of worker trail orientation after presentation of an oversupply of this compound (30 µg). Established trails were recorded by overhead webcam and ants digitized, before and after presentation of the treatment. The coefficient of determination or trail integrity statistic, r2 was then calculated. Ants initially showed high linear trail integrity (r2=0.75). Within seconds of presentation of the trail pheromone treatment, the ants showed little or no further evidence of trail-following behavior (r2=0.16-0.49). Disrupting fire ant recruitment to resources is expected to have negative effects on resource collection, colony size, colony migration, and other effects yet to be determined. Recently Argentine ant trails were disrupted for up to two weeks in the field using a microencapsulated trail pheromone. Further research is needed to establish the long-term effects and control potential for trail disruption in S. invicta.