• Korean Journal of Environmental Biology
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• v.41 no.3
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• pp.193-203
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• 2023

Ethyl formate (EF) is a naturally occurring insecticidal compound and is used to control pests introduced from abroad, in quarantine, by a fumigation method. In particular, it is mainly used as a substitute for methyl bromide and is less toxic to humans and less harmful to plants. This study aimed to investigate the possible acute toxicity of EF to useful organisms, and how to reduce phytotoxicity in watermelon, zucchini, and oriental melon. After fumigation with EF for 2 h, the LC₅₀ values for earthworms, honey bees, and silkworms were 39.9, 7.09, and 17.9g m^-3, respectively. The degree of susceptibility to EF was in the order of earthworms, silkworms, and honey bees based on the LC₅₀ value, and EF fumigation induced stronger acute toxicity to honey bees. Phytotoxicity was observed in watermelon leaves treated with a concentration of 7.5 g m^-3 EF, and when treated with a concentration of 10.0g m^-3, it was confirmed that the edges of watermelon leaves were charred and seemed to be damaged by acids. Zucchini and melon, and other cucurbits, showed strong damage to the leaves when treated with a concentration of 10 g m^-3, and sodium silicate, at concentrations of 10% and 20%, was used to reduce phytotoxicity. Therefore, acute toxicity towards nontarget organisms and phytotoxicity during the fumigation of EF should be reduced for efficient agricultural pest control.

• Horticultural Science & Technology
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• v.16 no.3
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• pp.374-376
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• 1998

Effects of traditional fumigation (methyl bromide; MB) and combined fumigation (methyl bromide/phosphide; $MB/PH_3$) on the disinfestation, and phytotoxicity and longevity of cut flowers (lily and rose) were investigated. Combined fumigation with low concentrations of $7/3g/m^3\;(MB/PH_3$) at $10^{\circ}C$ immediately after transportation from harvested place was found to be much more effective in disinfestation of aphid, mite, and thrips than fumigation with $MB\;48g/m^3$ only at $20^{\circ}C$ after simulated transportation for 2 days. Quality and longevity of cut flowers measured after fumigation were better in flowers treated by combined fumigation ($7/3g/m^3,\;MB/PH_3$) at $10^{\circ}C$ for 2.5-3 hrs, irrespective of pretreatment with pulsing solution immediately after transporation, even though phytotoxicity varied with cut flowers fumigated. On the other hand, fumigation with $MB\;48g/m^3$ only at $20^{\circ}C$ after simulated transportation for 2 days showed tendency of enhanced insect disinfestation, but caused phytotoxicity to both lily and rose, regardless of pretreatment and moreover, reduced the longevity of the cut flowers.

• Journal of Environmental Policy
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• v.13 no.4
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• pp.135-159
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• 2014

Industrial insect is defined as the insect utilized in industries that creates added value. Most of the industrial insects used in Korea are exotic species that are introduced through artificial means. Despite the rapid expansion of market for industrial insects, the system for risk assessment of industrial insects is not being adequately conducted. Although Korea carries out a risk assessment for the species designated as disease and insect pest by Animal and Plant Quarantine Agency, far too little consideration is being given to overall ecosystem, as the control system is covered in the Plant Quarantine Law. To solve this problem, we analyzed the Korean risk assessment system and looked at systems in other countries. The results show that it is essential for stakeholders to reach an agreement to set up fundamental directions for the system. Unless the integration system of taxonomical and ecological information is prepared, the ecological risk assessment should be conservative to protect ecosystems and should also follow the precautionary principle. It also requires cooperation among the ministries. In addition, the results indicated that a differentiation between risk assessment and screening is urgent. Several solutions such as setting up clear objectives in both assessment and screening stages, target species, steering organization and assessment criteria assessment systems from were proposed as practical institutional strategies. Among many foreign countries the assessment system from Ireland equally considers various factors such as economical, ecological safety and management aspects, It is also based on precautionary principle to fulfil its original purpose. It was suggested that the Ireland system would be the best reference that can be modified and applied into the Korean system by considering distinct characteristics of the industrial insects.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.1
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• pp.128-136
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• 2015

This study investigated the effects of low-dose electron beam irradiation treatment on physicochemical and sensorial properties of imported navel oranges during storage at $3^{\circ}C$ for 45 days. The samples were irradiated at doses of 0.2, 0.4, 0.6, 0.8, and 1.0 kGy, and changes in their color values, hardness, Brix/acid ratio, total sugar contents, reducing sugar contents, vitamin C contents, and sensory evaluation were investigated. There were no significant differences between non-irradiated and irradiated samples in terms of color values, Brix/acid ratio, total sugar contents, total reducing sugar contents, and vitamin C contents. Hardness of irradiated sample at 1 kGy decreased significantly in the early storage period, but the difference between non-irradiated and irradiated samples decreased again at the end of storage. For the sensory evaluation, scores of color, sweetness, flavor, and overall acceptability decreased as irradiation dose and storage period increased. Samples irradiated at over 0.8 kGy showed low preference in all scores except color. These results suggest that electron beam irradiation below 0.6 kGy does not affect physicochemical and sensory properties; thus, electron beam irradiation up to 0.6 kGy in imported navel oranges is optimum for minimizing quality changes and disinfestation treatment simultaneously.

• Korean journal of applied entomology
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• v.59 no.1
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• pp.25-35
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• 2020

The striped fruit fly, Zeugodacus scutellata, is endemic in Korea, but it has been regarded as one of the serious quarantine pests throughout the world. Sterile insect release technique (SIT) has been used to eradicate quarantine fruit flies. This study developed a technique to generate sterile males and applied SIT to control Z. scutellata. First of all, the reproductive systems of Z. scutellata adults were examined with fluorescent microscope. Polytrophic ovaries comprises of around 100 follicles with developing oocytes. Each follicle contains an oocyte with several nurse cells and are surrounded with follicular epithelium. Oocyte development began at 10 days after adult emergence (DAE) and formed chorionated oocytes after 20 DAE. On the other hand, male testes were well developed just after adult emergence. The vas deferens was filled with motile sperms. To generate sterile males, different doses (0~1,000 Gy) doses of electron beam were irradiated to 3~5 days old pupae of Z. scutellata. When male pupae were irradiated with electron beam at 200 Gy, they developed and mated with females without any significant difference compared to untreated males. Although the untreated females mated with the 200 Gy-irradiated males laid eggs, no eggs did not hatch. The 200 Gy-irradiated males were then applied to untreated male and female flies in a density ratio of 1:9 (untreated males : treated males). The laid eggs suffered significant infertility. These results suggest that electron beam-irradiated pupae at 200 Gy resulted in male sterility and the resulting males would be applied to SIT.

• Korean journal of applied entomology
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• v.60 no.2
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• pp.255-262
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• 2021

The potato tuber moth, Phthorimaea operculella (Zeller) has been known as a quarantine pest of potato. This study investigated inhibition doses of electron beam irradiation (EBM) by comparing their effects on the development and reproduction and DNA damage of the insect pest. Eggs (0-12 h old), larvae (3^rd and 5^th instar), pupae (less than 1 d old after pupation) and adults (less than 1 d old after emergence) were irradiated with increasing doses of EBM. The EBM with 150 Gy could not completely prevent the hatchability of eggs and pupation of the hatched larvae. The hatchability from the irradiated eggs were 19.3%. However, adult emergence from the irradiated eggs were completely inhibited. When 3^rd and 5^th instar larvae were irradiated at 100 Gy, the adult emergence from the irradiated larvae and the fecundity of the adults were completely inhibited. When pupae and adults were irradiated at 300 Gy and 400 Gy, respectively, the hatchability of the F₁ eggs was completely inhibited. The alkaline comet assay on the level of DNA damage by EBM in P. operculella adults indicates that the EBM increased DNA damage level in a dose-dependent manner, and the damage was repaired in a time-dependent manner. These results may recommend EBM of 150 Gy as a phytosanitary treatment for P. operculella. However further confirmative study is required for the practical application of this EBM dose for P. operculella disinfestation.

• Korean journal of applied entomology
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• v.42 no.3
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• pp.173-184
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• 2003

Beetles belonging to the families Scolytidae, Platypodidae, Bostrichidae, and Lyctidae intercepted from imported timbers at Busan port were investigated from March 1 to November 30 in 2000. In addition, hosts imported country were examined. A total of 52 species of within 23 genera was intercepted from nineteen species of timbers or logs from fifteen countries. In Scolytidae, 35 species of 16 genera in three subfamilies were identified 12 species in Xyleborus, 6 species in Ips, 3 species in Trypodendron, 2 species in Arixyleborus, and 12 species of all different genera including Alinphagous. Scolytidae were intercepted from 16 species of timbers in 13 genera imported from 11 countries. The highest beetles were intercepted from Malaysian lauan. In Platypodidae, 9 species of one genus (Platypus) were intercepted from 6 species of timbers in 4 genera imported from 6 countries including Australia. The highest numbers were intercepted from Malysian lauan. In Bostrychidae, 5 species of 4 genera in two subfamilies were intercepted from 6 species of timbers in 4 genera imported from four countries. In Lyctidae, Trogoxylon sp., Minthea sp., and Minthea rugicollis were intercepted from 3 species of timbers in 2 genera imported from 3 countries.

• Korean journal of applied entomology
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• v.62 no.4
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• pp.227-243
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• 2023

The Asiatic pink stem borer, Sesamia inferens (Walker, 1856) (Lepidoptera: Noctuidae) is a pest that attacks rice stems. In this study, we estimated the annual generation of insect in several regions of the Republic of Korea. Adult trapping using a sex pheromone trap detected the occurrence of S. inferens adults in the three northernmost areas around 38° latitude and showed that the insect inhabits all of Korea. In most areas investigated, the seasons of the adult generations estimated using the single-sine degree-day model did not deviate from the corresponding observed seasons of adult occurrence. We estimated that the overwintering larvae hypothetically-estimated using the model could be originated from the last generation of adults. When larvae collected in paddy fields during the autumn season in a few middle and southern areas were reared at 25℃, ca. 70% of pupae did not show additional larval molting before their pupation. All larvae collected in early March in a southern area (Goseong, Gyeongsangnam-do) pupated without additional larval molting when reared at 25℃. Based on these results, we presumed that S. inferens could overwinter as mainly the last instar larval stage in the area. Taken together, we conclude that S. inferens primarily has two generations per year in areas around 38° latitude, and three generations in the areas between 35.3° and 37.3° latitude. In addition, approximately 35% of insects captured by the sex pheromone trap were species other than S. inferens, as determined by analyzing the nucleotide sequences of the cytochrome c oxidase 1 gene. These species were not morphologically misidentified as S. inferens.