The alfalfa weevil (Hypera postica) is an important pest that causes significant damages to alfalfa crops, reducing yield and quality, but there’s a solution. This research had two main goals to evaluate the efficacy of insecticides available in Korea for alfalfa weevil control and to provide data for pest management studies. The experiment, conducted from 2023 to 2024 at the National Institute of Animal Science in Cheonan, Republic of Korea, included four treatment plots: control (CON), early-occurrence (EAR), mid-occurrence (MID), and late-occurrence (LAT). It also included two frequency plots with primary and secondary insecticide using 50% fenitrothion emulsion, which made it truly comprehensive study. The primary insecticide was applied at the first observation of the alfalfa weevil larvae, with subsequent secondary applications at specified intervals. The results showed that two-times insecticide applications significantly reduced larvae populations and increased yield and nutrient content compared to a single application. Specifically, control rates ranged from 94 to 94.7% on the third day after treatment and from 72.2 to 93.4% on the seventh day. Plots with two applications had higher yields and crude protein content. The study concluded that the timing and frequency of insecticide applications are critical to maximizing alfalfa yield and quality, emphasizing the importance of optimized application strategies for effective pest control.
This study aims to contribute to resolving the critical issue of weed management in newly established alfalfa fields, study has been conducted on effective herbicide use. The study evaluated the impact of various domestically available foliar herbicides on alfalfa phytotoxicity, weed control, yield, and nutritive value. The experiment was designed in a randomized complete block design with four treatments. Alfalfa ‘SW 5615’ seeded in the spring of 2024 on a 1 ha field (March 18), with herbicide treatments including fluazifop-P-butyl (FPB), bentazone (BEN), and a mixture of these herbicides (MIX). Herbicide efficacy, alfalfa yield, and nutritive value were assessed 30 days post-application. Results indicated that the MIX treatment achieved superior weed control comparable to hand weeding (HW), although it exhibited higher phytotoxicity, requiring extended recovery periods. While MIX led to lower overall yield, it enhanced alfalfa purity, resulting in higher crude protein (CP) content and relative feed value (RFV) compared to other treatments. The study concludes that despite the potential for increased phytotoxicity, mixed herbicide treatments could offer a strategic advantage in enhancing the quality of alfalfa feed through effective weed management, thereby improving CP and RFV, critical factors for the nutritional value of alfalfa. These findings provide valuable insights for optimizing weed management practices in alfalfa cultivation, suggesting that mixed herbicide application, although associated with increased phytotoxicity on the plants, could improve the overall feed quality by reducing weed competition.
Salmonella enterica subsp. enterica serovar Gallinarum biovar Gallinarum causes fowl typhoid in poultry. In this study, we isolated Salmonella from a Korean retail chicken shell egg and performed whole-genome sequencing, from which we identified one chromosome (4,659,977-bp) and two plasmids (plasmid_1: 87,506 bp and plasmid_2: 2,331 bp). The isolate serotype was confirmed to be Gallinarum, with a biovar type of Gallinarum, which was finally identified as Salmonella enterica subsp. enterica serovar Gallinarum biovar Gallinarum. Multilocus sequence typing confirmed that the isolate was that of sequence type 78. The antimicrobial resistance gene, aac(6')- laa, was identified on the chromosome, and 166 virulence genes were detected on the chromosome and plasmid_1.
After the permanent shut down of Kori Unit 1, various decommissioning activities will be implemented, including decontamination, segmentation, waste management, and site restoration. During the decommissioning period, waste management is among the most important activities to ensure that the process proceeds smoothly and within the expected timeframe. Furthermore, the radioactive waste generated during the operation should be sent to a disposal facility to complete the decommissioning project. Square and cylindrical concrete re-package drums were generated during the 1980s and 1990s. The square, containing boron concentrates, and cylindrical, containing spent resin, concrete re-package drums have been stored in a radioactive waste storage building. Homogeneous radioactive waste, including boron concentrates, spent resin, and sludge, should be solidified or packaged in high-integrity containers (HICs). This study investigates the sequential segmentation process for the separation of contaminated and non-contaminated regions, the re-packaging process of segmented or crushed cement-solidified boron concentrate, and re-packaging in HICs. The conceptual design evaluates the re-packaging plan for the segmented and crushed cement-solidified waste using HICs, which is acceptable in a disposal facility, and the quantity of generated HICs from the treatment process.
To non-destructively determine the burnup of a spent nuclear fuel assembly, it is essential to analyze the nuclear isotopes present in the assembly and detect the neutrons and gamma rays emitted from these isotopes. Specifically, gamma-ray measurement methods can utilize a single radiation measurement value of 137Cs or measure based on the energy peak ratio of Cs isotopes such as 134Cs/137Cs and 154Eu/137Cs. In this study, we validated the extent to which the results of gamma-ray measurements using cadmium zinc telluride (CZT) sensors based on 137Cs could be accurately simulated by implementing identical conditions on MCNP. To simulate measurement scenarios using a lead collimator, we propose equations that represent radiation behavior that reaches the detector by assuming “Direct hit” and “Penetration with attenuation” situations. The results obtained from MCNP confirmed an increase in measurement efficiency by 0.47 times when using the CZT detector, demonstrating the efficacy of the measurement system.
New motor development requires high-speed load testing using dynamo equipment to calculate the efficiency of the motor. Abnormal noise and vibration may occur in the test equipment rotating at high speed due to misalignment of the connecting shaft or looseness of the fixation, which may lead to safety accidents. In this study, three single-axis vibration sensors for X, Y, and Z axes were attached on the surface of the test motor to measure the vibration value of vibration. Analog data collected from these sensors was used in classification models for anomaly detection. Since the classification accuracy was around only 93%, commonly used hyperparameter optimization techniques such as Grid search, Random search, and Bayesian Optimization were applied to increase accuracy. In addition, Response Surface Method based on Design of Experiment was also used for hyperparameter optimization. However, it was found that there were limits to improving accuracy with these methods. The reason is that the sampling data from an analog signal does not reflect the patterns hidden in the signal. Therefore, in order to find pattern information of the sampling data, we obtained descriptive statistics such as mean, variance, skewness, kurtosis, and percentiles of the analog data, and applied them to the classification models. Classification models using descriptive statistics showed excellent performance improvement. The developed model can be used as a monitoring system that detects abnormal conditions of the motor test.
최소 사후 경과 시간(PMImin) 측정에 필수적으로 이용되는 것 중 하나가 시식성 곤충의 발육 속도를 정확히 측정한 데이터이다. 법의곤충학(Medicolegal entomology)을 이용한 최소 사후 경과 시간 측정 방법은 과거에 비해 빠르게 발전하고 있지만, 보다 정확한 데이터를 얻기 위해서는 추가적인 기초 데이터 확보가 필요하다. 이에 본 연구에서는 가장 대표적인 시식성 곤충 중 하나인 연두금파리(Lucilia illustris)를 대상으로 온도에 따른 성장 속도를 측정하였다. 흔히 blow fly 또는 green bottle fly라고도 불리는 연두금파리는 사체에 가장 먼저 나타나는 시식성 파리 중 하나이기 때문에, 해당 종의 유충 성장 속도를 측정하면 최소 사후 경과 시간을 비교적 정확하게 추정하는 것이 가능하다. 실험에 사용된 연두금파리는 5~9월경 대전 유성구 일대에서 성충을 채집하여 종 동정, 사육 및 증식, 예비 실험을 거친 후 본 실험을 진행하였다. 본 실험은 성충 사육 케이지 내에서 교미 및 산란 유도 후 산란된 알을 돼지 생간에 접종하여 유충 사육 전용 챔버에 넣고, 12시간 간격으로 6개체 샘플링하고 추가로 각 령기 변화 시점에 샘플링을 진행하였다. 샘플링된 유충은 길이 측정 및 이미지 촬영을 진행하였다. 16℃, 19°C, 22°C, 25°C, 28°C, 31°C, 34°C 7개 온도 조건에서 연두금파리의 성장 속도 측정 실험을 3회 반복하였으며, 산란으로 부터 부화 및 우화까지 시간 등을 포함한 전체 성장 시간 데이터와 유충 몸길이 데이터, 이미지 자료, 샘플링한 유충 액침표본 등을 확보하였다. 16℃, 19°C, 22°C, 25°C, 28°C, 31°C에서 연두금파리의 전체 성장 시간은 각각 792.7±70.2, 441.0±53.3, 366.7±15.1, 288.0±7.2, 255.7±4.0, 260.3±13.2로 측정되었으며, 34°C에서는 3령 이후 성장 하지 못하고 폐사함을 확인하였다. 본 연구의 결과는 연두금파리의 성장 과정 데이터와 최소 사후 경과 시간 추정을 위한 지표로서 활용 가능한 데이터를 제공한다.
Division of the risk management, APQA(Animal and Plant Quarantine Agency) is conducting the IRA(Import Risk Assessment) to prevent the introduction of pests when importing foreign agricultural products. In the 2023 IRA, 55 cases of 19 items from 23 countries was analyzed, and fresh avocado(variety: HASS) from the Philippines was concluded in September 2023 and can be imported in accordance with appropriate phytosanitary measures. The main issue in the IRA of fresh avocado fruits from the Philippines was whether HASS variety avocados were host plants of Bactrocera dorsalis. As a result of the risk analysis, B. dorsalis were included in the pest list that needs to be managed by special risk management. As a risk management for B. dorsalis, one trap using methyl-eugenol is installed per 20 ha once a week. After surveying, if the population is more than 2/trap/day, control measures such as adding traps and spraying pesticides are necessary. As equivalence, regionalization, and transparency have been strengthened with the recent entry into force of the mega FTA, a higher level of scientific basis is required. Accordingly, division of the risk management, APQA is working harder to improve its expertise, and we need your cooperation and attention of the IRAs.
Dysmicoccus brevipes (Cockerell), Dysmicoccus neobrevipes Beardsley and Pseudococcus longispinus (Targioni-Tozzetti) are widely-distributed pests that feeds on many economically important hosts, particularly tropical fruits and ornamentals. The potential distribution of these mealybug pests into South Korea remains a primary concern because of their high incidence in interceptions screened during inspection. Hence, these species prompted a modelling effort to assess their potential risk of introduction. Potential risk maps were developed for these pests with the CLIMEX model based on occurrence records under environmental data. The potential distribution of these pests in South Korea in the 2020s, 2050s and 2090s was projected based on the RCP 8.5 climate change scenario. Results show that D. brevipes, D. neobrevipes and P. longispinus have little potential for invasion in the exterior environment of South Korea due to high cold stress in the 2020s. However, for D. brevipes and P. longispinus, 3 and 86 locations in Jejudo, were predicted to be marginally suitable for this pest under future climate factors, respectively. In that respect, the results of these model predictions could be used to prepare a risk-based surveying program that improves the probability of detecting early D. brevipe, D. neobrevipes and P. longispinus populations.
Subgenus Bothynoptera Schaum, 1863 of the genus Parena is mainly found in Oriental region. Despite this widespread distribution, species of the subgenus Bothynoptera are poorly known in Korea. While a total of 14 species have been recorded worldwide, only 3 species have been recorded in Korea. In this study, as a revisional work of Korean known species, a pictorial key and photographs of habitus and male genitalia for each species are provided, with a newly recorded species in Korea.
Currently, 12 subspecies of Coptolabrus smaragdinus have been recorded in Korea, of which 7 subspecies are listed in South Korea. C. smaragdinus has limited movement due to degenerated hindwings, resulting in high intraspecific diversity due to geographic isolation. Previous studies have been mainly classified based on external characters or genitalia structure, but the differences between subspecies are very ambiguous. In this study, we aimed to more clearly distinguish at the subspecific classification level, by examining the male aedeagal and inflated endophallus. Additionally, we provide photos of adult, endophallus and the process of endophallus inflation.
The continuous use of pesticides with the same mode of action has lead to the development of insecticide resistance in the target pests. Establishing pesticide resistance management methods and effective control strategies for these pests has become an important target. Bemisia tabaci, a representative pest of greenhouse, directly affects the growth of crops at all stages of its development except eggs. It also causes indirect damage by secreting honeydew that eventually promotes sooty mold in leaves and fruits. In this study, eight insecticides with different mechanisms of action (Flonicamid, Fluxametamide, Spinetoram, Cyantraniliprole, Dinotefuran, Pyridaben, Milbemectin and Pyriproxyfen), and registered for use against cucumber B. tabaci were selected and tested for insecticide resistance. The tested populations of B. tabaci were collected from greenhouse cucumber cultivations in 12 domestic regions. The results were presented as RR (Resistance ratios), and CEI (Control efficacy index) values.