Physical Methods for Electrical Trap-and-Kill Fly Traps Using Electrified Insulated Conductors

SIMPLE SUMMARY: Electrostatic insect exclusion is a physical approach to pest control in which an apparatus forming an electric field (EF) is applied to capture pests. Previous studies have clarified the insect-capture mechanisms of such tools and evaluated their practicality. In the present study, we investigated the biological impact of an EF-forming apparatus on adult houseflies captured by the device. We observed the release of substantial levels of negative electricity from the captured flies, detectable as a specific and transient electric current. The electric current was detected at the time of physical attraction, and during subsequent confinement of the fly to the apparatus. The magnitude of electric current from the fly was voltage-dependent, and detrimental effects caused by electricity release became more apparent as the applied voltage increased. Bioelectrical measurements showed that electric current caused acute damage and delayed the death of captured flies. These findings demonstrate the insecticidal function of the insect-capturing apparatus and provide an experimental basis for establishing a tool for trap-and-kill pest management. ABSTRACT: In the present study, we analyzed negative electricity released from insects captured by an electric field (EF)-producing apparatus. Adult houseflies (Musca domestica) were used as the model insect. The EF producer consisted of a negatively charged polyvinyl chloride membrane-insulated iron plate (N-PIP) and a non-insulated grounded iron plate (GIP) paralleled with the N-PIP. An EF was formed in the space between the plates. A housefly placed on the GIP was physically attracted to the N-PIP, and electricity released from the fly was detected as a specific transient electric current at the time of attraction and during subsequent confinement of the fly to the N-PIP. The magnitude of the insect-derived electric current became larger as the voltage applied to the N-PIP increased. We determined the total amount of electric current and confinement time within the apparatus necessary to kill all captured flies. These results demonstrate the insecticidal function and insect-capturing ability of the EF-producing apparatus.