Since methyl bromide(MB) has been designated as ozone deplete substance(ODS) by Montreal protocol (1989), many MBalternative fumigants like ethyl formate and phosphine gas were developed and commercialized. Ethyl formate(EF) is an effectiveMB alternative fumigant to control insect pests on imported fresh commodities. It is important to develop a proper evaporationmethod to apply EF on large scale fumigation because EF has a high boiling point(54℃). Recently, concurrent treatment ofethyl formate and nitrogen(EF+N2 treatment) has been newly developed. At preliminary test, EF+N2 treatment showed goodevaporation rate and showed high efficacy on quarantine pests without phytotoxicity on fresh commodities. In this trial, we’veapplied the EF+N2 treatment on imported orange and lemon at pilot scale (0.5m3, 10m3) containers and commercial scale containerto validate efficacy and phytotoxicity. 70g/m3 of EF liquid was applied on orange and lemon by EF+N2 treatment method,and showed 100% mortality on tested insect pest(Tetranychus urticae) without phytotoxicity at 0.5m3 and 10m3 scale fumigationtrials, respectively. At commercial scale trial, EF+N2 treatment also showed 100% efficacy on T. urticae and there was nophytotoxic symptoms on imported orange and lemon fruit. These results indicate that the newly developed EF+N2 treatmenthas a potential as a MB alternative, and can be applied on imported fresh commodities for quarantine and pre-shipment purpose.

국내 정부양곡 보관창고에서는 알루미늄포스파이드 정제를 사용하여 쌀 해충 방제를 실시하고 있다. 이 약제는훈증시간이 4~7일로 장시간 소요되며, 제형 특성상 분말(잔사물)제거가 필요하고, 훈증완료 후에도 3~5%의 미반응물질이 남아있는 것으로 알려져 있다. 따라서 신속하고 안전한 새로운 훈증기술개발이 필요한 실정이며, Methylbromide(MB) 대체훈증제인 Ethyl formate(EF)와 Phosphine(PH3)의 병행처리를 통해 국내 주요 저곡해충인 가루좀벌레(장두)에 대한 약효를 조사하였다.가루좀벌레 성충을 대상으로 데시케이터 실험을 통해 도출된 100% 방제 가능 조건인 EF+PH3(16.6 + 1g/m3),24시간을 금속훈증상(1m3)에서 처리한 결과 가루좀벌레에 대해 100% 방제효과를 확인하였다. 본 연구는 양곡보관창고 훈증처리시 알루미늄포스파이드 대체제로서 EF+PH3의 사용 가능성을 제시하였다.

Ethyl formate has been used for the control of insect pests by fumigation. However, there were not many reports toshow its target site of fumigant toxicity on insect pests since its first use in the agricultural industry. In the present study,we showed the presumable target sites of ethyl formate fumigation in insect pests using Myzus persicae nymphs. Afterethyl formate fumigation, the nymphs of this species were collected and the changes at the biochemical and molecularlevel were determined. The activity of cytochrome c oxidase (COX) was approximately two-fold higher after ethyl formatefumigation. In addition, the expression levels of acetylcholinesterase (AChE) decreased gradually with increasing ethylformate concentration. These two findings suggested that COX and AChE might be the major target sites of ethyl formatefumigation. In addition to these results, the analysis of lipid content using MALDI-TOF MS/MS identified 9 phospholipidsdifferently generated 2-fold higher in the ethyl formate-treated nymphs than that in the control nymphs, thereby leadingto changes in cell membrane composition in M. persicae nymphs. Therefore, the ethyl formate fumigation caused lethaleffects on M. persicae nymphs by changing COX activity, AChE gene expression, and phospholipid production.

The spotted wing drosophila (SWD), Drosophila suzukii, is classified exotic quarantine pest in Australia and EU, soSWD-free must be supported by evidence of surveys and phytosanitary measures in exported host agricultural commoditiesin Korea. From a quarantine control point of view, SWD is importantly considered as model insect pest for exotic fruitflies (Bactrocera dorsalis) in Korea as well because of similarity in ecological cycles. In evaluations of ethyl formate(EF) only and combined cold treatment to kill eggs and larvae of SWD, the combined EF fumigation applied at LCt50%(50% killed lethal concentration X time) and cold treatement (5℃) for > 5 days showed the promise to new conceptfor eradicating quarantine pest and these could be helpful to pre-develop exotic fruit fly management in Korea.

Fumigation activity of Frankliniella occidentalis, western flower thrips, and phytotoxicity were evaluated with phosphine(PH3) and ethyl formate (EF) in the asparagus. Fumigation activity of PH3 and EF showed in the order of egg (64.7 mg·h/Land 132.9 mg·h/L), nymph (5.5 mg·h/L and 14.8 mg·h/L), and adult (3.8 mg·h/L and 14.7 mg·h/L) respectively at 5˚C in12 L desiccator. The adsorption of PH3 was 24% at 5˚C. However, the adsorption of EF increased sharply to 98% at 5˚C.PH3 showed 100% control for all development stage of F. occidentalis with 4g/m3 in 0.65m3 at 2˚C for 48h exposure. Thephytotoxicity was not found. The results revealed that the EF is highly absorbable in asparagus, so it is not suitable as afumigant, but PH3 is considered to be suitable as an alternative MB fumigant for control of the F. occidentalis in asparagus.

Ethyl formate (EF) and methyl salicylate (MS) are naturally occurring and generally safe substances for use. Sub-lethaldoses of EF and MS were evaluated to find synergistic fumigation action against azuki bean beetle (ABB), Callosobruchuschinensis (L.). Susceptibility of the ABB to EF was in the order of eggs =adults >larvae >pupae. Adults was most sensitiveto MS, and followed by eggs. Larvae and pupae were highly tolerant to MS. However, in synergistic effects of EF andMS showed that all the stages of ABB were highly sensitive in the order of adults >eggs >larvae >pupae. Highest synergisticratio was found against adults when using LC10 of both EF and MS as compared to other stages. Notably, MS synergizedthe EF exposure to all stages of ABB. This finding paves the way to exploiting synergistic activity of MS and EF againstABB for the safeguard of stored azuki bean grains.

To replace methyl bromide (MeBr) due to its ozone depletion properties and the life-threatening to related worker as well as fumigators, ethyl formate (EF) fumigation on exported and imported fruits and vegetables has been developed by QIA in Korea since 2005. The benefits of using ethyl formate (EF) fumigant is considered as the safest practice among the commercially available chemical alternatives. The issues was that the cylinderized EF with carbon doxide (CO2) is not enough to extend their applications in terms of fumigation cost. We have developed the cost-effective liquid EF applications with nitrogen gas and demonstrated in quarantine trials (10m3) on imported bananas. We showed the new 35 gm-3 of EF applications with inert gas (nitrogen), were completely control all stage of citrus mealybug (Planoccous citri) for 4hr fumigation at 13°C. These applications meet the quarantine guidelines and protocols in terms of efficacies to target pest and safety concern as well as satisfactions of consumers showing no damages to imported bananas. Extensively, this cost effective EF technology could be acceptable to other fruit and vegetable commodities to reduce the fumigation costs and green house gas (CO2).

The resistance of maize weevil(Sitophilus zeamais), an important agricultural pest of stored grain, on aluminium phosphide fumigant(PH3) has been reported recently in Korea. Many researchers reported that ethyl formate(EF), a potential methyl bromide alternative fumigant, showed good efficacy on several grain pests. In this trial, based on CTP (concentration × time products), we evaluated efficacy of EF on phosphine resistant and susceptible maize weevil. Each of insect strains were collected in grain storehouses and examined the PH3 resistance according to FAO method (Busvine, 1980). L(Ct)90 of PH3 resistant and susceptible strain was 48.3 and 0.3 g h m-3, respectively. When treated with EF, L(Ct)90 of PH3 resistant and susceptible strain was 90.0 and 110.9 g h m-3, respectively. In the case of EF, there was no difference between resistant and sucsecptible strain compare with PH3. These results indicates that EF is a potential alternative for aluminium phosphide resistance management in grain storehouses.

The spotted wing drosophila (SWD), Drosophila suzukii, is a severe pest of berry fruits like strawberry, blueberry, sweet cherry and grape in terms of quarantine. For the disinfestation of SWD, methyl bromide (MeBr) is the only option in quarantine practice. However, MeBr's current use will be phased out due to chronic inhalation toxicity to fumigators and related worker as well as ozone depletion properties. To replace MeBr, we evaluated the efficacy of ethyl formate (EF) and phosphine gas (PH3) to all different developmental stages of SWD at practical fumigation condition (>25 ℃). To achieve complete control of all stages of SWD, PH3 required > 6 hr exposure when applied at > 1.0 g m-3. In case of 4hr EF fumigation, the LCt99 (LCt99, 99% lethal concentration × time) of EF to egg, larvae and pupae of SWD was 198.09, 77.42 and 115.55 g·h m-3, respectively.

The bulb mite (BM), Rhizoglyphus echinopus, is hard to control in the harvested onion and garlic. Methyl bromide (MeBr) fumigation is the only option to eradicate BM at present. However, MeBr causes phytotoxic damage (index 3) to onion and garlic and highly toxic to fumigators. To replace MeBr, we evaluated ethyl formate (EF) and phosphine gas (PH3) to BM at 5℃ which is current practical fumigation temperature. The >140 g·h m-3 of EF for 24 h could completely control BM and this CT (concentration × time) product was slightly (index 1) phytotoxic to onion and garlic. Fumigation of 2 g PH3 required >120 h exposure to kill 100% of BM without any pyhtotoxic damage. Further researches are being planned to shorten the exposure time with synergistic effect between EF and PH3.

Ethyl formate (EF), a methyl bromide alternative fumigant which is commercially used for quarantine and pre-shipment(QPS) purpose, has a potential to control various insect pests. Based on CTP (concentration × time products), we've firstly evaluated fumigation trials of EF on cucumber plants to eradicate horticultural insect pests in greenhouse. In the preliminary test, EF achieved 100% control of cotton aphid, western flower thrip and tobacco whitefly when CTP of EF was 4.4, 5.6 and 3.3 g h m-3, respectively. In 1300m3 scale cucumber greenhouse trial, EF was applied with 2g m-3 dosage for 15 hrs, and cotton aphid, western flower thrip and tobacco whitefly were completely controlled without phytotoxic symptom. EF fumigation could be suitable for greenhouse cultivation in terms of good efficacy on horticultural insect pests with labor-saving benefit than current insecticide spraying applications.

Exportation of sweet persimmon has been grown up recently, but the growth was accumulated because of quarantine and shelf life issues. Herein, we've investigated the concurrent processing of ethyl formate (EtF), a MeBr alternative quarantine fumigant, and 1-methylcyclopropene (1-MCP), an anti-ethylene compound, on sweet persimmon and suggested proper fumigation methods. An important quarantine pest, Tetranychus urticae, was inoculated on sweet persimmon, and then 70 g m-3 of ethyl formate has been fumigated for 6 h before and after 1 ppm of 1-MCP treatment for 24 h at 5°C condition. These concurrent processing showed the promise that efficacy of EtF was enough to meet quarantine guideline and shelf life of fruits was extended in terms of the hardness, surface color and sugar contents when treated fruits were stored for four weeks at 5°C.

The German cockroach, Blatella germanica, is one of the most important household pest that can cause disease on human. Conventional contact insecticides show less efficacy because it is hard to be contacted or digested by cockroach that lives inside small crevice. Ethyl formate(EF), which is a potential fumigant to control various insect pests such as stored grain insects and quarantine pests, can be penetrated wherever air exist and shows toxicity on respiratory system of insect. In this trials, we've demonstrated practical and commercial scale fumigations of EF on German cockroach. Efficacy of EF was described in terms of concentration × time (CT) product. At practical fumigation, EF gave 100% control of German cockroach nymph and adult when the CT product was 43.2g h m-3. When 600m3 scale warehouse fumigation for 15 hours with 5g m-3 of EF, nymph and adult stage of German cockroach were completely controlled. The ventilation time to reduce EF concentration under TLV(Threshold Limit Value, EF=100ppm) was less than 1 hour. These results show that EF can be applied at warehouse or mill house to control German cockroach effectively.

검역훈증제로 사용되어져온 메틸브로마이드(MB)가 오존층파괴물질로 규제가 예상됨에 따라 대체제로서 에틸포메이트(EF), 포스핀(PH3)등을 이용한 화학적 소독처리기법이 개발 중에 있다. EF는 천연물질유래의 물질로 식품첨가물로 훈증처리시 작업자 안전성이 높은 대체제이며, 현재 일부 수입 과실류의 특정 해충(깍지벌레류)만 소독처리기준을 설정하고 있어 처리기준 이외의 해충 발견시 MB훈증을 하고 있는 실정이다. 다양한 해충별, 태별 온도별에 대한 EF 약제 감수성을 평가하여 소독처리기준에 적용하고자한다. 본 실험에서는 다중 농도의 EF 훈증제(10~60 mg/L)를 사용하여, 각 공시충(담배가루이, 목화진딧물, 복숭아혹진딧물, 귤가루깍지벌레, 점박이응애 등)에 대해 온도별 (5℃, 13℃, 20℃) 약효를 Probit 분석한 결과 5℃ 조건에서는 점박이응애 성충이 감수성 정도(LCT99)가 가장 높았다. 13℃ 조건에서는 점박이응애 성충 및 귤가루깍지벌레 약충이, 20℃ 조건에서 점박이응애 약충 및 귤가루깍지벌레 성충이 각각 높은 감수성을 보였다.

Methyl bromide(MB) is a fumigant for quarantine and pre-shipment(QPS) that can eradicate target pests within short fumigation periods. However, MB, an ozone-depleting substance, is scheduled to be phased out in the second decade of this century. In contrast to MB alternatives for soil fumigation, there is no ideal alternative fumigant to MB for QPS of perishable commodities. It is important that all target insect pests are killed within a short fumigation time. The citrus mealybug(Planococcuscitri), a problematicquarantine pest from Korea, was exposed to ethyl formate and phosphine for different times and to different concentrations of EF(0.0∼33.4 mg/L) and PH3(0.25∼1.0 mg/L) in small desiccators. The eggs showed more tolerance than the nymphs and adults. To control the eggs, they were treated with a mixture of EF and PH3 for 2 and 4-hr. The egg stage showed 100% mortality with EF:PH3(25.1:0.25, 16.7:0.5, and 16.7:1.0 mg/L) at 4-hr. Treatment with a mixture of EF and PH3 for 4-hr at 8°C can control all stages of the citrus mealybug.

This study was done to evaluate the efficacy of Vapormate (ethyl formate 16.7 % + CO2) as an methyl bromide-alternative fumigant. Some insect pests and mites were found under calyx of sweet persimmon fruits, including grape-myrtle scale, two-spotted spider mite, Amblyseius eharai. Vapormate fumigation was equally toxic to miticide- susceptible and -resistant T. urticae showing 100 % mortality at higher concentration than 146.7 and 211.0 mg/L, respectively. In persimmon-filled desiccator, summer and overwintering types of T. urticae showed 100 % mortality at higher concentration than 163.7 and 265.8 mg/L, respectively. Sweet persimmon damage from vapormate fumigation was not shown by the days after treatment. Tolerance of each live stage of grape-myrtle scale was in descending order: egg < nymph < adult. EF 141.5 mg h L-1 for 6 h at 5 ℃ killed 100 % of the larvae of D. punctiferalis. The final scaled-up fumigation confirmed the efficacy of EF to target pests and non-phytotoxicity on persimmons. In conclusion, EF may become a MB alternative fumigant for sweet persimmon, and the LC99 values of EF may be used to practical applications to all kinds of insects and mites on harvested sweet persimmon.

Aphids are common pests frequently found in imported and exported fruits and vegetables. Methyl bromide(MB), a Quarantine and Pre Shipment(QPS) fumigant, could offer eradication of aphids within short period. However, MB is limited in use because of poor gas evaporation at low temperature(<5℃) and there is phytotoxic effect or damage on quality in post-harvest vegetables and fruits even at >5℃. Two candidates of MB alternative, ethyl formate(EF) and phosphine(PH3), are used and being investig at edonvarious fruits and vegetables fumigation to replace MB. Aphids are known as quarantine pest that are hard to control when conduct short period fumigation with PH3 and low dosage of EF. In this paper, dose response assessment of EF and PH3 are presented for three different aphid pecies : cotton aphid(Aphisgossypii), green peach aphid(Myzuspersicae) and turnip aphid (Lipaphiserysimi). The LCt99% values of EF at room temp. and low temp. (5℃) were 4.42 and 4.45 g·h·m-3 for cotton aphid, 3.23 and 5.58 g·h·m-3 for turnip aphid, 3.23 and 5.58 g·h·m-3 for green peach aphid when 2-hours fumigation. PH3 showed 0% efficacy on all species when 2-hours fumigation.

Methyl bromide (MB), as a fumigant for Quarantine and Pre-Shipment(QPS) could offer eradication of target pests within shorter fumigation period and without phytotoxicity. 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(Planococcuscitri), problem quarantine pest, was tested with different exposure times(2 and 4-hours) and concentrations(EF(0-200 g/m3) and PH3(10-50 g/m3)) in small desiccators for mixture tests. On sensitivity test with small desiccator, the egg stage showed 100% mortality with 200/25(EF/PH3) g/m3 and the nymph and adult stage showed 100% mortality with 10/10(EF/PH3) g/m3 on 2h. Also, the egg stage showed 100% mortality with 150/25(EF/PH3) g/m3on 4h.

The fumigant activity of phosphine (PH3) and ethyl formate (EF) was determined to all stage of Phthorimaea operculella (Zeller) under high oxygen concentration (50% and 80%). Oxygenated PH3 and EF were tested at two different temperatures (20°C and 4°C) during 7 days. Two oxygenated fumigants were treated with LC10, 30 and 50 values of single fumigant against each stage of P. operculella. At 10% inhibition of hatchability concentration value, inhibition of hatchability of P. operculella eggs was shown 20.3% and 9.2% with 50% and 80% oxygenated PH3 at 20°C at 1 day after treatment, respectively. The fumigant activity of oxygenated PH3 was increased at all stage of P. operculella except eggs both 20°C and 4°C. However, oxygenated EF was determined low fumigant efficacy to hatchability of eggs and emergence rate of pupae. The insecticidal activities of P. operculella larvae and adults were slightly increased mortality rather than single EF. In this result suggests that oxygenated phosphine is effective method for managing P. operculella. But, oxygenated EF is not effective.

The potato tuber moth, Phthorimaea operculella (Zeller), is considered one of the main causes of potato losses during harvesting and storage. The pest occur throughout the year and its larvae damage the leaves, twigs and tubers. In this study, we have investigated the effects of ethyl formate (EF) and phosphine (PH3) against P. operculella. Fumigation to all stage of P. operculella was carried in a desiccator system at 5℃ and 20℃ for 24 h. As a result, LC99 of PH3 to all stage of P. operculella was showed 1.953 mg L-1 (eggs), 0.100 mg L-1 (larvae), 4.884 mg L-1 (pupae) and 0.240 mg L-1 (adults) at 20℃, respectively. LC99 of EF to all stage of P. operculella was observed 19.808 mg L-1 (eggs), 6.783 mg L-1 (larvae), 141.476 mg L-1 (pupae) and 3.223 mg L-1 (adults), at 20℃ respectively. Larvae and adults showed the highest susceptibility to PH3 and EF at 20℃. LC99 of PH3 to all stage of P. operculella was showed > 1.5 mg L-1 (eggs), 0.187 mg L-1 (larvae), > 1.5 mg L-1 (pupae) and 0.386 mg L-1 (adults) at 5℃ , respectively. LC99 of EF to all stage of P. operculella was showed 27.479 mg L-1 (eggs), 9.580 mg L-1 (larvae), 55.759 mg L-1 (pupae) and 3.084 mg L-1 (adults) at 5℃, respectively. These results indicated that the fumigant efficiency of PH3 and EF is more effective with treated in room temperatures against termites.