Phosphine is a common pesticide used to control grain pests in Rice Processing Complex(RPC). However, increasing use of aluminum phosphide caused the occurrence of phosphine resistance pests. In this study, phosphine resistance pests collected at RPC in 2023 was investigated with FAO No. 16 test, Dihydrolipomaide dehydrogenase(DLD) test and amino acid mutation analysis to identify the occurrence of phosphine resistance in Korea. Tested pests were collected in the 7 province 35 region. As a result of the FAO test of 21 regions, all sample were phosphine sensitives. In DLD test and amino acid analysis, 7 region samples were weak resistances. It is required to inspect the RPC and other grain storage continuously to inhibit the widespread of resistant pest.

Historically, the control of stored-product insects has mostly relied on the use of fumigants such as methyl bromide (MB) and phosphine. However, methyl bromide is no longer used for structural fumigations, and phosphine insecticide resistance is rising globally. Methyl benzoate (MBe) is a new green pesticide that occurs naturally as a metabolite in plants. In this study, we evaluated the the potential use of MBe as a fumigant against a variety of stored-product insects. According to our laboratory findings, MBe showed strong fumigation toxicity against the Indian meal moth and flat grain beetle with an LC50 value of 0.1 μL/L and 0.76 μL/1.5 L air, respectively, compared to the other tested insects. Furthermore, no significant differences were observed in susceptibility levels between the lab strain and the phosphine-resistant lesser grain borer and rice weevil. However, the red flour beetle had the highest LC50 value of 8.26 μL/1.5 L air. Overall, MBe seems to be a highly promising candidate for the development of environmentally-friendly alternative fumigants.

현재까지의 저장시설 내 저장해충 방제는 주로 메칠브르로마이드(MB)나 PH3와 같은 고독성 훈증제를 사용하여 왔으나 이와 같은 화학약품의 사용은 인축에 잔류독성이나 생태계 파괴와 같은 부작용을 초래하였다. 따라서 화학약품 의 사용을 최대로 억제하면서 친환경적이고 효과적인 방제방법이 요구되고 있다. 본 연구는 이산화염소(ClO2) 가스를 이용하여 저장시설 내 대표적 저장해충인 화랑곡나방과 어리쌀바구미의 치사율, 생존율, 부화율, 용화율 및 발육일수 등의 생태적 특성을 조사하여 이산화염소의 저장해충에 대한 효과와 적용 가능성을 검증하고자 하였으며, 연구는 실험실과 야외 운반용 컨테이너 및 실제 저장시설인 미곡처리장에서 진행되었다. 이산화염소 가스를 이용한 저장해충 방제는 기존 훈증제의 사용을 대체할 수 있는 효과적이고 친환경적인 방법으로 저장시설의 규모, 농도, 처리시간, 대상해충 종에 따라 효과적으로 조절이 가능하여 방제효과와 경제성 두 가지 측면을 극대화 할 수 있을 것이라 생각된다.

Heating for disinfestation has been practiced of at the condition of 55-60°C for at least 48 hours in various facilities of stored and processed agricultural products. However, it has been required to reduce temperature and time due to the economic efficiency. To improve disinfestation efficiency of heating, we demonstrated whether combined treatments of heat with other agents exert synergistic for disinfestation. Heat treatments were combined with 1 ppm diatomaceous earth (DE), 10 ppm phosphine or 10% carbon dioxide against Plodia interpunctella, Sitophilus zeamais and Tribolium castaneum. Insects were treated single or multiple combinations of each component for 6 h at either 25°C or 40°C, then mortalities were monitored for 14 days post-treatments. Combined treatments greatly enhanced mortalities and shorten killing time of three species rather than single treatments. Particularly, heat treatments with 1 ppm DE and 10 ppm phosphine completely lethal within 3-6 h post-treatments, but heating with 10% CO2 was not much effective. Among three species, S. zeamais adults were more suscpetable to heat but both larvae and adults of T. castaneum was highly susceptible to phosphine. Our results clearly showed that combined treatment of DE or phosphine with mild heating (40°C) greatly improved mortalities of three major stored pest insects and provide advanced techniques for disinfestation of stored product pests.

Fumigant effects of six plant essential oils (Helichrysum angustifolia, H. gymnocepha, H. splendidum, Arachis Hypogaea (peanut oil), Mentha arvensis (corn mint oil), and Thymus magnus (thyme oil) were tested against the adults of three grain storage insects (Lasioderma serricorne, Sitophilus zeamais, and Tribolium castaneum). Among them, the corn mint oil revealed to have fumigant toxicity against L. serricorne (LD50 = 1.3 ㎕ L-1), S. zeamais (LD50 = 3.6 ㎕ L-1), and T. castaneum (LD50 = 16.2 ㎕ L-1). The chemical constituents of corn mint oil were analyzed using GC-MS as follows: (-)-menthone (15.3%), isomenthone (10.0%), methyl-cetate (5.0%), β-caryophyllene (9.1%), and 1-menthol (48.1%). To enhance the fumigant toxicity, ethyl formate was added. This novel formulations of mixture could find significant differences in terms of their synergistic effects.