Ethyl Formate as a New Sanitary Treatment for Disinfesting the Hitchhiking Insect Pest Halyomorpha halys on Imported Nonfood Agricultural Machinery

With an increase in the international trade of agricultural and non-agricultural products, there is an increase in the possibility of introducing hitchhiking insect pests such as Halyomorpha halys, which has been detected on imported vehicles and agricultural machinery. Although methyl bromide (MB) is provisionally used to control invasive pests, it is classified as a restricted chemical owing to its potential to deplete the ozone layer and pose health risks to humans in cases of inadequate ventilation, as well as concerns regarding consumer safety. Therefore, this study investigated ethyl formate’s (EF’s) efficacy against H. halys and its efficacy and sorption, as an alternative to MB, on main electronic components, including alternators, ignition coils, and motors. Fumigation with 35 and 70 g/m3 EF for 4 h at 15 °C had no damage on the main electronic components as evaluated using various operation tests. In a commercial trial, H. halys infestation was effectively controlled with 35 g/m3 EF fumigated for 4 h at 23 °C using a 30 m3 polyvinyl chloride tarpaulin fumigation chamber. After ventilation, the EF concentration decreased below the safety level within 10 min and reached the zero level within 40 min for worker safety. This novel sanitary treatment using EF fumigation on imported agricultural machinery could be an effective method without causing mechanical damage.