Efficacy of ethyl formate and phophine, applied alone and in combination, on imported pineapple to control on Citrus mealybug (Planococcus citri) Jeong-OhYang 1, Dong-Hoon Cho 1, Min-Goo Park 1, Bong-Su Kim 2, and Byung-HoLee 2* 1 Animal Plant Quarantine Agency, Plant Quarantine Technology Center 2 Dongbu ARI, Dongbu Farm Hannong Co. Ltd Exposure time (hr) Fumigant Conc. (mg/L) Temp. ( ℃ ) PH 3 EF ±1 EF + PH EF EF + PH Mortality of Pest Citrus mealybug Container Gas exposure Fumigation Gas concentration Methyl bromide (MB), as a fumigant for Quarantine and Pre-shipment (QPS) could offer eradication of target pests within shorter fumigation period. Therefore, unlike MB alternatives for soil fumigation, there is no ideally MB alternative fumigant for QPS purpose, particularly for perishable commodities. It is critically important that within shorter fumigation time requires killing all target insect pests and without effect of quality and deliver treated fruit and vegetables to the final consumer. The citrus mealybug (Planococcus citri), problem quarantine pest, was tested with different exposure times, EF 2hr and PH3 24hr, and different concentrations, EF ( mg L-1) and PH3 ( mg L-1), in small desiccators. The eggs of citrus mealybug showed most resistance than other stages about nymph and adult. To control the eggs of citrus mealybug treated the mixture of EF and PH3 during 2 and 4hr. The egg stage showed 100% mortality with EF/ PH3 (25.1 up /0.25, 16.7 up /0.5, and 16.7up /1.0 mg L-1) on 4h. The results obtained from 4 hours fumigations in 0.5m3 with mixtures of EF at 16.7 and 25.1 mg/L respectively with PH3 at 1.0 mg/L, and different load ratios of 15.6 and 20.8% demonstrated that the higher concentration of EF and lower load ratio, the higher mortality was achieved. The results obtained from 4 hours fumigations in 10m3 with mixtures of EF at 25.1 mg/L with PH3 at 1.0 mg/L, and load ratios of 15.0% demonstrated that the mortality was achieved at 100% about eggs of citrus mealybug. Ethyl formate with phosphine mixture application can control to the all stages of citrus mealybug for 4hr at 8 ℃. Abstract Abstract Materials & Method Materials & Method Results Results Added phosphine fumigant improve the toxicity of ethyl formate fumigant to adult and nymph stages of mealybug. This tendency is showed at all treatment (4 and 2hr). Especially, Treatments using mixture gas show 100% mortality of mealybug at shorter exposure time than treatment using ethyl formate only. Fig. 2. Dose-response graph of EF (a) and PH 3 (b) to adult and nymph stage of mealybug for 2h expose at 8 ℃ (a) (b) (a) (b) Fig. 3. Toxicity of EF(blue dot) mixture gas (EF+PH mg/L, red dot) to adult (a) and nymph (b) stage of mealybug for 2h exposure at 8 ℃ SummarySummary EF CT(gh/m3) Mortality (%) Fig. 1. Comparison of toxicity of EF(blue dot) and mixture gas (EF+PH 3, red dot) to adult (a) and nymph (b) stage of mealybug for 4h exposure at 8 ℃ EF CT(gh/m3) (a) (b) EF CT(gh/m3) Mortality (%) EF CT(gh/m3) Mortality (%) CT(gh/m3) Mortality (%) CT(gh/m3)