A New Approach: Ethyl Formate Fumigation to Control Bemisia tabaci (Hemiptera: Aleyrodidae) in a Yellow Melon Vinyl House

Due to concerns over the resistance development to existing pesticides, chemical poisoning among farmers, and chemical residue on crops, sprung up a growing need to develop new pest control strategies for utilization in protected houses in Korea. A series of experiments tested a new technology using a fumigant, ethyl formate, in growing crops in the protected houses. It was revealed that the glasshouse was inadequate for the fumigation system using the fumigant since ethyl formate gas sharply decreased due to gas leaking through the gaps between the glass frames. On the other hand, the gas concentration was stable during the fumigation process. Experiments were also conducted to evaluate its phytotoxicity on cucurbits crops (yellow melon). The crops were fumigated at 20^◦C in three fumigation schedules (2, 4, and 12 h). The results revealed that the developmental stages of yellow melon showed no sign of phytotoxicity in all conditions. However, the fumigation damaged the shoots of red pepper in higher humidity and at a longer duration. Interestingly, Bemisia tabaci were (100%) completely killed in all these conditions. Based on the results of the above experiments on the high efficacy on the control of Bemisia tabaci and zero phytotoxic effects of the ethyl formate fumigation on yellow melon, verification experiments for the effectiveness were conducted thrice in farmer’s yellow melon vinyl houses and once in a farmer’s cucumber vinyl house. Results demonstrated that ethyl formate fumigation for 2 h at 2 g m⁻³ concentration could 100% kill the adults of Bemisia tabaci with no phytotoxic effect on the crops. Therefore, we could conclude that the 2-h fumigation system with 2 g m⁻³ ethyl formate would be a new alternative to the existing chemical spraying methods.