The nematode Bursaphelenchus xylophilus and its vector insect Monochamus alternatus are major quarantine pests of timber products in Korea. Due to the phaseout of methyl bromide as a fumigant for plant quarantine and pre-shipment treatments, the need for an alternative fumigant is essential. Based on preliminary studies on the efficacy of ethanedinitrile (C2N2) to these two pests, three quarantine trials on logs covered with PVC-tarpaulins were conducted at three dosages and three temperatures potential for inhalation exposure was assessed by monitoring atmospheric levels of C2N2 in relation to the threshold limit value (TLV, 10 ppm, v/v). Concentration × time products (Ct) of 398.6, 547.2 and 595.9 g h m-3 were obtained for each quarantine trial. A 100% mortality of B. xylophilus and M. alternatus larvae at 23±4°C and 10±4°C occurred with a load factor of pine logs of 46% and at 3±1°C with a load factor of 30%. During all fumigant procedures, atmospheric levels of C2N2 20m downwind from the PVC tarpaulin were below the TLV. During aeration, levels 10 m and 5 m downwind were below the TLV after a maximum of 0.4 h and 1 h, respectively. For the purpose of an emergent quarantine or phytosanitary treatment, specific doses of C2N2 at the temperatures that occurred during fumigation could control B. xylophilus and M. alternatus larvae without significant inhalation risk to workers.

Ginger is generally consumed as food or medicine in Korea and mostly imported from China. During quarantine inspection,genus of nematodes, Meloidogyne spp. and Pratylenchus spp., are mainly detected and regulated under the procedure ofquarantine in Korea. We tested the susceptibility and mortality rates of Meloidogyne spp., which are infected in ginger,against a fumigant, Ethanedinitrile (EDN). Juveniles of the nematode showed 100 % mortality against EDN at 2.5 mg/Lfor 2 h at 13°C, meanwhile, egg mass showed 0 % hatching at 5 mg/L for 2 h at 13°C. A concentration × time product(CTP) was determined as 7.24 ghm-3. Under the 35% filling rate of ginger in cold chamber, 100% mortality was observedin both juveniles and eggs at 50 mg/L for 2 h at 13°C. At that condition, CTP was determined as 14.12 ghm-3. Basedon this study, EDN fumigation will be effectively apply to control of nematodes.

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.

Methyl bromide (MeBr) which is widely used in most of the countries for quarantine purpose, has been designated and under control as ozone depleting substance. This study is on the toxicity of ethanedinitrile as a MeBr alternative to control several wood-related insect pests. LC50 value of Ethanedinitrile(EDN) for Reticulitemes speratus, Tomicus piniperda adults at 21℃ was 0.26, 4.83 mg/L respectively. LC99 value of EDN for R. speratus at open status and closed wooden cubes was 0.65, 0.62 mg/L respectively, whereas MB was 13.96, 31.10 mg/L, which means that the toxicity of EDN for R. spratus is greater and EDN penetrates better into wood as compared with MB. The morality of EDN 20.3 mg/L(6hr) at 25℃ for Crytogenius lutats in wood was 90.3% in larvae, 58.6% in pupae and 89.5% in adults, which means that pupae were more resistant than larvae and adult. All stages of C. lutats were disinfected with EDN at or more than 29.9.mg/L, 6hr(CT product 89 mg hr/L) at 25℃. In sorption and application test, CT product of EDN 50 g/㎥(6hr) was 157 g hr/㎥ in the conditions of 21% wood moisture content with 25% loading, 171 g hr/㎥ in 54% wood moisture content with 25% loading and 158 g hr/㎥ in 54% wood moisture content with 50% loading, respectively. In all treatments, adults of Cryphalus fulvus and R. speratus were completely killed. The minimal CT product (158 g hr/m3) of 6hrs treatment was higher than CT product to disinfect C. lutats (89 mg hr/L). It is expected that it can be used as alternative fumigant of MeBr for woods.

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.