The existing ethyl formate fumigant is carbon dioxide (CO2) mixed liquified gas in metal cylinder, but this product type costs a lot to manufacture, translate and maintain cylinder. To supplement these problems, we have developed a new ethyl formate fumigation technique with nitrogen (N2) carrier. We assessed the susceptibility of mealy bugs, the most frequently detected pests in imported banana, and phytotoxicity of banana fruits. Ethyl formate and nitrogen were concurrently treated on citrus mealybug, one of the most resistant mealybug to fumigant, and ethyl formate was treated with LC50 product of independent treatment dosage. Nitrogen was treated with 7 dosages from 79% to 95% concentration. Phytotoxicity of banana was assessed by treating EF 35 mg/L with N2 79% for 14 days, and color, sugar contents and loss of weight were measured. EF with N2 treatment showed more than 50% of mortality on every growth stages, and there was no significant difference between control and treatment banana fruits. These results indicate that concurrent treatment of EF and N2 can be used to control mealybug in banana fruits.
Methyl Bromide (MB) has been regulated by montreal protocol due to ozone depletion since 1992, and there is a need to develop MB alternative fumigation methods. To find out the efficacies and tolerance in developmental stages of citrus mealybugs (Planococcus citri) which frequently infested in imported pineapples, phosphine(PH3) gas was tested in different exposure times (2~24 hr) and concentrations (0.1∼2g/m3) in small desiccators at 8℃. Based on Lethal 99% concentration × time products (LCTP 99%) of PH3 gas to target developmental insect, 2g/m3 PH3 was applied for 24 hr in 300 m3 fumigation facility, which was designed in well sealed and evacuation system (5 air exchange/min). We monitored PH3 gas in fumigation facility to confirm CTP and checked PH3 gas in atmospheres in air ventiliation process after fumigations to make quarantine guideline and protocol for worker safety as well as efficacy to target pest.