Stored grain pests can cause reduction of grain quantity, quality, commercial value and germination rate. Susceptibility of three fumigants, methyl bromide, ethyl formate and phosphine, were assessed on Tribolium castaneum, which is an important stored grain pest. On susceptible insects, LCT50 of phosphine was 0.654mg h/L for egg, 0.127mg h/L for late larvae, 0.105mg h/L for pupae and 0.048mg h/L for adult stage, respectively. LCT50 of methyl bromide was 33.193mg h/L for egg, 14.585mg h/L for late larvae, 8.616mg h/L for pupae and 11.967mg h/L for adult stage, respectively. LCT50 of ethyl formate were 25.165mg h/L for egg, 80.912mg h/L for late larvae, 176.326mg h/L for pupae and 68.578mg h/L for adult stage, respectively. On resistant insects, LCT50 of phosphine were 82.325mg h/L for egg, 33.315mg h/L for late larvae, 73.546mg h/L for pupae and 55.707mg h/L for adult stage, respectively. LCT50 of methyl bromide were 19.250mg h/L for egg, 43.413mg h/L for late larvae, 76.842mg h/L for pupae and 19.387mg h/L for adult stage, respectively. LCT50 of ethyl formate were 87.552mg h/L for egg, 113.457mg h/L for late larvae, 200.122mg h/L for pupae and 85.394mg h/L for adult stage, respectively.

우드펠렛은 가정용, 상업용, 산업용 등으로 사용되며 특히 화력발전소에서 석탄 대용으로 수입량이 급증하여 연간 약 2,400만톤 가량 수입되고 있는 상황이다. 우드펠렛 검역훈증제로 기존에는 메틸브로마이드(이하 MB)가 최근까지 사용되어져 왔으나, MB의 높은 흡착률과 우드펠렛의 과도한 수용비로 인해 최종가스농도 기준에 미치지 못하여 재투약하는 사례가 빈번히 발생해 문제가 되어져왔다. 이를 해결하기 위해 농림축산검역본부에서는 올해 초 MB와 포스핀을 병행으로 처리하는 방식의 소독처리기준을 신설하였다. 새로운 소독처리기준이 설정됨에 따라 배기시 안전한 배기시간 수준을 설정하기 위해 병행처리 후 수착과 탈착되는 가스농도를 조사하였다. 실내 훈증상에 우드펠렛을 채우고 약제 처리한 결과 각 훈증제의 TLV(Threshold Limit Value)-TWA(Time Weighted Average) 기준이하로 농도가 감소되는 배기시간은 25℃일 때 MB는 120시간, 포스핀은 6시간으로 측정되었고 15℃일 때 MB는 186시간, 포스핀은 19시간으로 측정되었다.

수출입 묘목류에 있어서 깍지벌레류는 주요한 해충으로 다양한 묘목류에서 검출되고 있다. 깍지벌레류 중 우리나라의 소나무에 피해를 주고 있는 소나무굴깍지벌레는 연 2회 발생하는 해충으로 1세대는 4월, 2세대는 8월에 발생하여 소나무 잎에 피해를 준다. 따라서 본 연구에서는 수출입 묘목류에서 검출되는 깍지벌레류의 소독효과에 대한 정보를 제공하기 위하여 포스핀과 에틸포메이트 그리고 메틸브로마이드를 이용하여 소나무굴깍지벌레를 대상으로 훈증효과를 검정하였다. 포스핀을 소나무굴깍지벌레 알을 대상으로 0.06 mg/L 이상 처리시 난부화억제율은 100%였으며, 에틸포메이트 처리의 경우 성충은 2.6 mg/L, 알은 7.4 mg/L에서 100% 살충활성을 보였다. 그리고 메틸브로마이드를 40 g/㎥으로 2시간 훈증처리시 소나무굴깍지벌레 성충은 100% 치사하였으며, 알의 경우 26.0 mg/L을 처리했을 때 100%부화억제 효과를 보였다.

The overall goal of this USDA-ARS research is to ensure the protection and quality of stored product foodstuffs. The results of this research directly enhance production, distribution, and safety of foodstuffs, promote and retain access of United States-grown crops to domestic and foreign markets, and protect the United States and trading partners from the agricultural, ecological, and economic threat posed by quarantine and invasive pests. In general, USDA-ARS research related to the fumigation of stored products focuses on the development of techniques to rapidly disinfest raw products of field pests, control pests in processed products amenable to re-infestation and microbial infection, and reduce reliance on fumigation as a stand-alone measure for postharvest disinfestations and disinfections. Specific research objectives include: comparative evaluation of alternative fumigants to methyl bromide in postharvest applications, development of novel technologies to reduce and eliminate atmospheric emissions from chambers used in postharvest fumigation, and design production strategies that allow for a more strategic postharvest use of methyl bromide and alternative fumigants. Recent research findings will be presented and discussed.

Methyl bromide (MB) had been routinely used in quarantine and pre-shipment (QPS), despite of strong recommendations to replace technically feasible alternatives of it by International Plant Protection Convention (IPPC) and current hazardous issues in workplace related post-fumigation process of imported perishable commodities. Due to insufficient ventilations post-fumigation on imported fruits such as citrus, fumigators and related workers in cold storage, load/unload and packing room has been exposed to hazardous conditions (5-100 ppm, MB’s TWA_TLV = 1 ppm). It’s time to replace newly developed phytosanitary disinfestation methods such liquid ethyl formate (EF) with N2 application. It could provide for safer workplace involved on and post-fumigation process, cost-effectiveness as well as meet the environmental friendly solution.

The current protocols of methyl bromide (MeBr) fumigation on imported nursery plants, which are seriously infested with quarantine mealy bugs and scales, could be reevaluated because there were no limited uses of loading ratio, packing types etc. Another emerging issues is that the workplace health issues on MeBr fumigation are related with poor ventilation etc as well as well-known phytotoxic damages on them. In previous report, we have evaluated the efficacies of ethyl formate (EF) and phosphine (PH3) on different types of mealybugs. Herein, the phytotoxic damages of EF and PH3 on Alocasia, Sansevieria, Cactaceae and Croton genera were evaluated in terms of chlorophyll contents, color changes etc. This study showed that EF and PH3 fumigation on imported plants could be applicable to replacement of MeBr with further confirmation trials.

Methyl bromide (MeBr) is well-known as a hazardous chemical to exposed fumigators and related workers as well as a ozone depletion chemical. According to recent report in USA and Korea, when MeBr fumigated on orange and grape at low temperature (<10℃), absorbed MeBr on fruits was slowly released to workplace. To replace MeBr practices urgently, ethyl formate (EF) fumigation is considered safer to worker (TLV of EF = 100 ppm compared to MeBr's = 1 ppm) and free from residual problem. We reports confirmative liquid EF (FumateTM) with N2 trials, which is cost-effective and non-CO2 gas emitted, on imported grapes. The 4hr-fumigation of 70 gm-3of EF (CTP > 114 gh-3) in scale-up chamber (10m3) fumigation (20% l.r.), showed efficacies to many kinds of insect pests, non-phytotoxic damage, providing safer guideline at workplace.

The susceptibility of the Cigarette beetle, which are pests in tobacco, to methyl bromide and phosphine fumigants was evaluated. Five concentrations of each methyl bromide were selected for all stages and treated for 4 hours. As a result, 100% larvae were observed in eggs CT 51.20, late larva CT 73.61, pupa CT 71.87 and adult 52.87 mg h / L, respectively. The LCT50 values for methyl bromide were 13.896 for eggs, 36.038 for late larvae, 25.172 and 21.758 mg / l, respectively. The phosphine treatment was carried out for 5 to 6 concentrations (0.025, 0.051, 0.099, 0.501, 0.999 and 1.500 mg / L) for 20 hours. As a result, egg and late larvae showed 100% larvae at CT 5.137 and 6.435 mg h / L, respectively, and 61.9% and 98.9% of larvae and adult larvae were similar to each other. Pupae showed 86.4% larvae at CT 10.520 and 100% larvae at over 13.777 mg / h of CT. The LCT50 values for phosphine were 0.317 for eggs, 0.649 for late larvae, 3.748 for pupa and 0.703 mg / l for adults.

Wood pellets are used by Biomass-solid refuse fuel (Bio-SRF) has been imported from many East-Asia countries especially,Vietnam in Korea. Wood pellets are made through grind and high-pressure process shows different physical characterizationlike high methyl bromide (MB) absorption unlike other wood materials. Furthermore, detected pests in wood pellets havesimilarity with detected pests in stored grain. In this study, we analyzed susceptibility on pupa and adult stages of redflour beetle, Tribolium castaneum in wood pellets against mixture of MB and phosphine (PH3). Mixture treatment ofMB and PH3 was more effective than single MB treatment compare with control. Pupal stage showed more tolerant thanadult stage on each fumigant and 100% mortality was determined at 27 mg/L of MB only at 20°C. However, PH3 increasedMB toxicity on pupae that 100% mortality was observed at 100:1 ratio of MB (5 mg/L) and PH3 (0.05 mg/L) at 20°C.Based on this study, mixture treatment of different type of fumigant will be applied to control of quarantine pests.

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.

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 number of pest detection in wooden pellets has increased since wooden pellets as biomass-solid refuse fuel (Bio-SRF) was allowed an import in Korea. In this study, we analyzed an insecticidal effect on pupal and adult stages of red flour beetle (Tribolium castaneum) and maize weevil (Sitophilus zeamais) in wooden pellets using two fumigants, methyl bromide (MB) and phosphine (PH3), for establishing a guideline on fumigation. MB and PH3 both showed a dose-dependent manner in insect mortality after fumigation under 60% filing rate (FR) of wooded pellets in desiccator. In MB fumigation to T. castaneum, adults and pupae showed 100% mortality at 128 mg/L and 161 mg/L in 10°C at 24 h post treatment and pupae showed 100, 74, and 8% mortality against 99 mg/L of MB in 20, 40, and 40% FR, respectively. In PH3 fumigation, S. zeamais adults showed 92% mortality to 4 mg/L, meanwhile T. castaneum adults showed 100% mortality at 120 h post treatment.

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.

Methyl bromide (MB) fumigation is still allowed to use in quarantine treatment on imported timbers and logs, even though IPPC(International Plant Protection Convention) was strongly recommended to reduce their use in case of existing alternatives. A newly developing MB alternative fumigant, ethanedinitrile (EDN), showed the potential in terms of better efficacy to various timber pests and penetration into the timber than MB. Herein, for suggestion of quarantine guideline in Korea, we had verified the efficacies under different temperature conditions(5, 5-15, >15℃) and monitored TLV(Threshold limited value) of EDN post-fumigation for worker safety. The 6 scheduled doses of EDN depending on types of timber pest and temperature conditions had evaluated with PVC-Tarp tent(>100m3) with 40-50% loading factors of imported logs. To control normal wood related pests such as Japanese termite (Reticulitermes speratus) and bark beetle(Cryphalus fulvus), the scheduled doses 30, 40 and 40 g/m3 for 24hr fumigations showed >99% efficacy at 5, 5-15 and >15℃, respectively. The scheduled doses 100, 120 and 150 g/m3 for 24hr fumigations was also successful to gain the proved efficacies at 5, 5-15, >15℃, respectively, for the quarantine guideline to notorious wood related pests such as Japanese pine sawyer (Monochamus alternatus) and pine wilt nematode (Bursaphelenchus xylophilus). The recommended ventilation times with atmospheric conditions at ports was > 1 and > 2 hr under the fully uncovered and partially uncovered of fumigation tent conditions, respectively.

Since Montreal protocol in1989 designated MB(methyl bromide) as ozone depleting chemicals, IPPC(International Plant Protection Convention) has adopted replacing the MB with alternative chemical and reducing the rate of MB use in plant quarantine in 2008. Pineapples are one of the most frequently fumigated imported fruit with MB in Korea. However, there was no technically available replacement. Therefore, we evaluated phosphine(PH3) fumigation as alternative to MB in applying pineapples. In the preliminary test, PH3 gas in 12L desicators to calculate ranged to 0.1 from 2g/m3 was tested at 2 and 24hr exposure to target pest, citrus mealy bug(CMB, Planococcus citri). All different of stage of CMB was shown 100% mortality when 2g/m3 of PH3 applied for 24hrs at 8℃. To confirm studies designed in 0.5m3 fumigation chamber, all egg, nymph and adult stages of CMB was killed completely and there wasn’t any phytotoxic and quality damages on pineapples for 2 weeks post-fumigation periods at 8℃. In terms of commercial use, further commercial research will need to be carry out in cooperation with importers and fumigators.

Methyl bromide (MB) has been banned by Montreal Protocol due to ozone depletion in developed countries since 2005 but uses for quarantine & pre-shipment (QPS) remains exemption. Current MB alternatives such as phosphine gas, ethyl formate has been showing their potential in terms of their no phytotoxic damages to target perishable commodities post fumigation as well as their efficacy at low temperature. We evaluated phosphine (PH3) gas as MB alternatives welsh onion, carrot, and lettuce fumigation. on sensitivity test, larvae of Aphis gossypii were most tolerant to PH3 among the all stage of A. gossypii, Tetranychus urticae and Plutella xylostella. The LC99 and LCT99 value of mixture gas for adult of A. gossypii was 1.79 mg/L (24hr, 5℃) and 33.56 mg h/L(5℃), respectively. On confirmation trials scheduled in 28m3 container for 24hr at 5℃, all stages of T. urticae was completely controlled in 2g/㎥ of phosphine gas, but A. gossypii and M. persicae were not completely controled. No phytotoxic damage was observed in vegetables.

With the increasing trend of global trades and protection of agro-ecosystem in importing and exporting countries against quarantine pest, quarantine and pre-shipment(QPS) fumigation in perishable commodites like strawberry is critical in terms of quality maintenance of fumigated commodites. Currently, there are limited use of MB fumigation on fruits and vegetables due to low temperature storage and phytotoxic effect or damage in postharvest qualities in many commodites. In this paper, efficacy and quality accessment of methyl bromide(MB) alternatives, ethyl formate and phosphine gas are presented for export strawberry. Efficacy of phosphine gas and ethyl formate are described in terms of concentration × time (CT) products to Frankliniella occidentalis, Aphis gossypii and Myzus persicae.

VapormateTM, the new gas formation of ethyl formate(EF) with carbon dioxide, is an MB(methyl bromide) alternative fumigant for grains and perishable commodities especially to control quarantine pest. To gain systematic efficacies of VapormateTM, vaporized gases in Tedlar bag were collected from liquefied gases in cylinder. Vaporized gases were used for collecting efficacy data to Tetranychus urticae, two-spotted spider mite, for 6hr at 26± 1℃. When applied 25, 51, 77 and 102 ml/L of vaporized gas for 6hr, mortality of T. urticae female adult were 83.3, 97.8, 100, and 100%, respectively, at 24hr after fumigation. Also, at 77 and 102 ml/L of vaporized gas for 4hr treatment at 26± 1℃, the mortality of T. urticae female was 96.7 and 97.8%, respectively. This preliminary result may help to understand further scaled-up VapormateTM fumigation applied with different type of commodities.

In Korea, methyl bromide(MeBr) is the only registered fumigant for quarantine application in imported timbers and wood packaging materials to control foreign wood-destroying pest. Under a agreement in the Clean Air Act and the Montreal Protocol to MeBr's ozone depleting properties, the use of MeBr is now strictly restricted and phased out year by year, even though there are exemptions for QPS (Quarantine and Pre-shipment) and CUE (Critical Use Exemption). However, due to increasing of global trades and protection of agro-ecosystem in imported counties against quarantine pests, MeBr in QPS use is increasing (16,304t in 2005, approximately 8.7% increase based on 1996), and domestic consumption of MeBr is recorded up to 938t (annual average among 2003 and 2005), especially the 67% percent (628t) of total MeBr uses imported timber and wood packing materials. Since ethanedinitrile (EDN) was patented by CSIRO in Australia, BOC and Dongbu have tried to develop and commercialize EDN as a timber fumigant. This is updated information on the developmental status of EDN, which included the biological efficacy to target pests and the penetrating aspect to target commodity in the semi-field and various field trials. Based on current results, EDN could replace MeBr for using timber fumigation and would play an important role in the ozone layer protection.