Ethyl formate fumigation for the disinfestation of red imported fire ants Solenopsis invicta Buren

The red imported fire ant, Solenopsis invicta Buren, is a serious invasive pest of quarantine significance. Potential establishment of this ant is of great concern in S. invicta free countries such as South Korea, where there have been multiple recent interceptions. The majority of those detections have been concentrated around main port areas of imported common trade containers, suggesting that disinfestation of the containers, in addition to inspection and disinfestation of containers with agricultural commodities, is necessary for the prevention of S. invicta introduction. So far, however, no regulations and protocols are in place for inspection, detection, and disinfestation of S. invicta in such containers. As a first step toward supporting such regulation, we investigated whether S. invicta could be effectively controlled using ethyl formate, a methyl bromide alternative. Ethyl formate fumigation treatment was effective in controlling 99.9% of S. invicta workers and female alates at 46.1 and 37.7 g h m⁻³ at 13 °C and 23 °C respectively. Our results provide evidence to support its use to disinfest S. invicta in containers. We discuss additional factors that need to be considered to develop disinfestation protocols for S. invicta in commerce shipping containers.