Principle of fumigant and fumigation

Yonglin Ren 한국응용곤충학회 2018 한국응용곤충학회 학술대회논문집 Vol.2018 No.10

Fumigation - one of the chemical methods - is the art of dispensing and applying gaseous substances especially for the purpose of disinfecting. It is an old and widely used technique for disinfestation of postharvest grain, fruit and vegetable. In a fumigation procedure, a gas is added to an enclosure for the purpose of controlling or eliminating undesirable organisms. The organisms may be pests of various types - such as insects, rodents, mites, and birds - or micro-organisms, or particular plants or seeds. The enclosure can be made from a diverse range of materials, including metal, concrete, bricks, mud and various plastic membranes. It is necessary to contain the fumigant while it acts on the target organism and to restrict its escape into areas where it may be dangerous to human health. In many situations fumigation may be the only feasible process for pest control as it does not require the commodity to be moved. Neither might it need specialized apparatuses, electricity, or manpower, and is relatively easy to apply in comparison with other methods, for example, heating and irradiation, as well as the use of protectants to control insects. Because fumigation is often the cheapest and most effective process available, it plays a major, world-wide, role in preserving commodities. However, researchers and operators not always fully understand principle of fumigant and fumigation practice to ensure select right fumigant and exposure time on different target insect pests and host commodities as well as application methods.

Comparison of respiration and metabolism between phosphine resistant and susceptible strain of insect

Yonglin Ren 한국응용곤충학회 2018 한국응용곤충학회 학술대회논문집 Vol.2018 No.10

The respiration rate of PH3 susceptible strain was significantly higher than the resistant strain. The results showed no significant effect of oxygen level on the respiration rate of both strains. Phosphine reduced the respiration rate of both strains when it was applied in average concentrations. However, the rate of respiration of the resistant beetles increased significantly under a high level of phosphine. The increase of respiration rate was associated with the higher emission of VOCs which prove the acceleration of metabolic processes to face the phosphine action for survival. Flat grain beetle Cryptolestes pusillus and rusty grain beetle C. ferrugineus are similar insect species, but only C. ferrugineus is capable to develop a high phosphine resistance. A direct immersion solid phase microextraction gas chromatography-mass spectrometry (DI-SPME-GCMS) technology has identified the different fatty acids from PH3 resistant and susceptible strain of Tribolium castaneum.

[Luncheon Plenary Lecture] Principle of fumigant and fumigation

Yonglin Ren 한국농약과학회 2018 한국농약과학회 학술발표대회 논문집 Vol.2018 No.10

Comparison of respiration and metabolism between phosphine resistant and susceptible strain of insect

Yonglin Ren 한국농약과학회 2018 한국농약과학회 학술발표대회 논문집 Vol.2018 No.10

Presently, NPQS Faces New Challenges in and out of The Country Due to The Changing Agricultural Circumstance Such As Opening of The Agricultural Market - Development and Use of Methyl Bromide Replacement -

YongLin Ren 한국응용곤충학회 2007 한국응용곤충학회 학술대회논문집 Vol.2007 No.10

Thermomechanical and electrical resistance characteristics of superfine NiTi shape memory alloy wires

Boheng Yang,Hui Qian,Yonglin Ren,Rende Wang 국제구조공학회 2022 Smart Structures and Systems, An International Jou Vol.30 No.2

Structural health monitoring and structural vibration control are multidisciplinary and frontier research directions of civil engineering. As intelligent materials that integrate sensing and actuation capabilities, shape memory alloys (SMAs) exhibit multiple excellent characteristics, such as shape memory effect, superelasticity, corrosion resistance, fatigue resistance, and high energy density. Moreover, SMAs possess excellent resistance sensing properties and large deformation ability. Superfine NiTi SMA wires have potential applications in structural health monitoring and micro-drive system. In this study, the mechanical properties and electrical resistance sensing characteristics of superfine NiTi SMA wires were experimentally investigated. The mechanical parameters such as residual strain, hysteretic energy, secant stiffness, and equivalent damping ratio were analyzed at different training strain amplitudes and numbers of loading.unloading cycles. The results demonstrate that the detwinning process shortened with increasing training amplitude, while austenitic mechanical properties were not affected. In addition, superfine SMA wires showed good strain.resistance linear correlation, and the loading rate had little effect on their mechanical properties and electrical resistance sensing characteristics. This study aims to provide an experimental basis for the application of superfine SMA wires in engineering.

New Formulations of Ethyl Formate to Control Internal Stages of Sitophilus oryzae

Byung-Ho Lee,Wan Huh,YongLin Ren,Daphne Mahon,Won-Sik Choi 한국응용곤충학회 2007 Journal of Asia-Pacific Entomology Vol.10 No.4

Ethyl formate (EF) was tested in mixtures with natural products (NPs) as a fumigant against the internal stages of Sitophilus oryzae. These novel formulations of EF [EF:NPs=9.0:1.0, (v/v)] were shown to be chemically stable for 1 month after initial mixing. Therefore, EF acts as a good solvent for various NPs having insecticidal activity. The toxicity of EF alone, and of the various EF formulations, was evaluated on each developmental stage at different concentrations and exposure times. The results show that the effect of EF alone, as compared with the various EF formulations, was similar or lower in the mixed age cultures (MAC) of S. oryzae after 6 hr of exposure. For the pupal stage of S. oryzae, EF + thujone showed increased toxicity (>20%) at both 6 hr of exposure at 67.4 mg/L, as well as at 24 hr of exposure at 37.6 mg/L. Also, EF + thujone, EF + menthone, and EF + carvone showed higher toxicities as compared to EF alone, on the pupal stage of S. oryzae after 24 hr of exposure at 37.6 mg/L. However, we couldn’t find significant differences in the formulations in terms of their synergistic effects. The most significant result of this research was the ability to use EF as a solvent for the application of various natural materials as fumigants and/or protectants. Our continuing research is aimed at finding natural product formulations that possess enhanced toxicity with respect to the internal stages of stored grain pests, as well as low mammalian toxicity.

Evaluation of Different Applications of Ethanedinitrile (C2N2) in Various Fumigation Chambers for Control of Monochamus alternatus (Coleoptera: Cerambycidae) in Naturally Infested Logs

Lee, Byung-Ho,Park, Chung-Gyoo,Ren, Yonglin Oxford University Press 2017 Journal of economic entomology Vol.110 No.2

<P>Monochamus alternatus Hopeis is an important vector of nematode pests of timber in Korea, particularly Bursaphelenchus xylophilus (Steiner & Buhrer) Nickle. Previously, we reported that ethanedinitrile (C2N2) has the potential to replace methyl bromide and metam sodium to control M. alternatus larvae and B. xylophilus under low-temperature (< 5 degrees C) conditions. Herein, we report on fumigation trials of C2N2 over a 3-yr period (February 2013-October 2015) conducted at higher temperatures. The trials were conducted under 24 different conditions that incorporated varying fumigation chamber types (plastic sheeting-enclosed chambers of differing construction or an ISO shipping container, interior size: 5.90 m length by 2.35 m width by 2.40 m height), log water content (24.1-43.5%), filling ratios (5, 20, and 40%), and temperatures (10.5-17.3 degrees C). Highest concentration x time (Ct) product values were obtained with the ISO shipping container followed (in order of decreasing Ct values) by a 0.1-mm-thick, low-density polyethylene tarpaulin enclosure, a 0.1-mm-thick polyvinyl chloride (PVC) tarpaulin enclosure, and a 0.05-mm-thick PVC tarpaulin enclosure. The correlation between Ct product value and mortality of M. alternatus larvae was calculated with all treatment combinations. From this, the L(Ct)(50) and L(Ct)(99) values for C2N2 were determined to be 73.19 and 194.90 g h m(-3), respectively. Ethanedinitrile showed promise as a practical alternative fumigant for use on fresh pine logs infested by M. alternatus larvae.</P>

Comparative studies on efficacy of ethyl formate and methyl bromide to disinfest citrus mealybug, Planoccous citri , on imported fruits

Min-Goo Park,Min-Goo Park,Chung-Gyoo Park,Jeong-O Yang,YongLin Ren,Byung-Ho Lee 한국응용곤충학회 2018 한국응용곤충학회 학술대회논문집 Vol.2018 No.10

To replace hazardous methyl bromide (MB) post-fumigation on imported fruits, due to insufficient ventilation process in industrial practice, alternative fumigation with liquid ethyl formate (EF) with N2 application, which is multi benefits to safe to workplace and environment, has been developed by APQA. Although EF was found to be shown proven efficacy to invasive external feeders such as mealybugs and scales on export and imported fruits and vegetables, there was still some conflicts to accept one of the phytosanitary disinfestation method somewhere because of on reliable and confirmative studies on between MB and EF in terms of efficacy to mealybugs on perishable commodities. In here, we evaluated comparative efficacy of EF and MB to target citrus mealybug, which was seems to be hard control pest, based on the current disinfestation guideline of them in Korea. The potential benefits of using liquid ethyl formate (EF) for future quarantine use could provide for safer workplace involved on and post-fumigation such as cold and packing storages, cost-effectiveness as well as meet the environmental friendly solution.

Efficacy of three fumigants, ethyl formate, methyl bromide and phosphine, toward Tribolium castaneum

Jeong Sun Park,Eun-Mi Shin,Young Ju Park,Bong-su Kim,Yonglin Ren,Jeongoh Yang 한국응용곤충학회 2018 한국응용곤충학회 학술대회논문집 Vol.2018 No.10

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.