Submitted to: Imported Fire Ants Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 7/19/2004
Publication Date: 9/16/2004
Citation: Chen, J. 2004. A New Bioassay for Evaluating Fire Ant Repellants. Imported Fire Ants Conference Proceedings.
Interpretive Summary: The red imported fire ant is a threat to households, agriculture and wildlife. Repellants can be used to repel fire ants from places where they are a nuisance. A new bioassay was developed to fast screen fire ant repellants. This new bioassay will be used to develop new fire ant repellant products that can exclude fire ants from sensitive areas where using insecticides is not appropriate, such as hospitals, schools and nursing homes.
Technical Abstract: A new bioassay for evaluating fire ant repellants was developed. The active ingredient was incorporated into sand within a liquid scintillation vial with an entry hole on the cap. Through the entry hole, fire ants dug and removed sand from the vial. The differences in amount of sand removed from the treated and control vials were used to evaluate chemical repellency. By using this bioassay, dimethyl and diethyl phthalates were found to be repellants to red imported fire ants. Two-choice tests showed that the minimum repellent concentration within 24 h was 100-ppm for both dimethyl and diethyl phthalates.