본 연구에서는 CyanoHABs를 제어하기 위해 주요 우점종인 Microcystis aeruginosa에 대한 항균 펩타이드의 살조 활성을 조사하고, 구조적 특이성을 바탕으로 새로운 M. aeruginosa 제어 펩타이드를 제작하였다. 본 실험에서 CAMA 유래 펩타이드 CMA1, CMA2와 Helicobacter pylori 유래 펩타이드 HPA3P, HPA3NT3는 처리 48시간 후 각각 67.3, 73.1, 76.7, 69.8%의 최대 살조 효율을 보였다. 또한, 신규 펩타이드 K160242~5는 처리 48시간 후 각각 64.0, 64.1, 66.4, 70.1%의 최대 살조 효율을 보였다. CA-MA 유래 펩타이드는 처리 24시간 이후 세포의 재성장이 관찰되었으므로 세포 표면과의 정전기 인력을 통해 세포를 응집하고 간접적으로 제어하는 것으로 조사되었다. 반면에, 양친매성 펩타이드는 세포의 재성장이 관찰되지 않았으므로 세포 응집과 더불어 세포 내 침투를 통해 직·간접적으로 세포를 제어하는 것으로 추정되었다. 또한, 펩타이드의 살조 기작 및 효율에는 구성 아미노산의 종류, 수, 구조 및 펩타이드의 분자량, 처리 농도 등이 복합적으로 영향을 미치는 것으로 나타났다. 그러나 펩타이드를 이용한 CyanoHABs의 제어 가능성을 제고하기 위해서는 정확한 기작과 관련 인자들의 확인 및 증명이 요구된다.

Foreign hazardous substances are likely to enter the country through imported foods as food trade between countries increases. The Sanitary and Phytosanitary Agreement allows countries to take preventive measures to protect the health of the people based on the Appropriate Level of Protection (ALOP). Thus, the country may establish its own food safety objective within the scope of the ALOP and implement more efficient food safety management system to achieve food safety goal. Therefore, more stringent control measures such as Hazard Analysis and Critical Control Point (HACCP) like systems should be applied to set and meet performance objectives at each stage of the food chain.

A simulation model of the 2010/11 foot-and-mouth disease (FMD) epidemic in the city of Andong, Republic of Korea was constructed to evaluate the epidemiologic effectiveness of FMD-control strategies. Seven FMD-control strategies were evaluated with respect to a number of epidemiologic indicators relating to the outbreak, including the number of infected animals, number of infected farms, and epidemic duration. The FMD-control strategies in the model consisted of pre-emptive slaughtering, movement restriction, and vaccination; however, levels of each control option differed. The constructed model was not perfectly representative of the 2010/11 FMD epidemic, although it was considered to mimic the actual FMD epidemic in its prediction of two outcomes: the median number of simulated FMD-detected farms was 294 (range 207–515), which was close to the number of farms detected (299) during the actual FMD epidemic (x2=87.239, df=98, p = 0.774); and the simulated epidemic curve was visually similar to the actual epidemic curve of the 2010/11 FMD epidemic. The effectiveness evaluation of simulated FMD-control strategies emphasized the amount the FMD outbreak size could have increased if the radius of the pre-emptive slaughtering area or the duration of movement restriction were decreased.

본 연구는 유기농 호박 재배시 문제가 되는 흰가루병을 효과적으로 방제하기 위한 난황유 플러스와 pH교정황토유황합제의 처리기술을 개발하고자 하였다. 50개 호박 품종을 이용하여 흰가루병, 역병, 시들음병에 대한 병저항성 정도를 검정한 결과, 공시한 대부분의 품종은 흰가루병에 대해 감수성으로 나타났다. 덩굴쪼김병에 대하여 저항성을 보이는 품종은 FR계통의 대목품종 8개였다.역병에 대해서는 대부분 감수성을 나타내었으며, 3개(SP12, SP45, SP48)의 품종만이 중도 저항성을 보였다. 유기농 호박흰가루병을 방제하기 위해서는 0.3% COY(cooking oil and egg yolk mixture)보다 0.3% COY plus (cooking oil and egg yolk mixture plus 0.2% soluble CuSO4)나 1.0% PLS(pH adjusted loess sulfurmixture)를 사용하는 것이 흰가루병의 방제 지속 기간이 길고 효과적이었다. 또한 유기농 호박농가에서 0.3% COY plus나 1.0% PLS를 단독으로 처리할 경우 1주나 2주 간격으로 처리하는 것이 흰가루병 방제에 가장 효과적이며 0.3% COY plus나 1.0% PLS를 조합으로 처리할 경우 3주 간격으로 처리할 경우 흰가루병 방제 효과가 우수하였다. 따라서 0.3% 난황 유플러스(COY plus)나 1.0% pH교정황토유황합제(PLS)를 조합으로 처리할 경우 흰가루병 방제 효과가 우수하여 방제 비용을 절감하여 매우 경제적일 것으로 생각한다.

Carbonyl sulfide(COS) is a naturally generated gas from fermentation process of microbes and from plant root and stem. COS was firstly registered as a fumigant at 1993 to control stored product pests. To supplement environmental problems and toxicity of commercial fumigants and develop new fumigant, we have processed the susceptibility assessment of carbonyl sulfide on important agricultural pests, Myzus persicae and Tetranychus urticae. Every growth stages of two insect species were tested, and five dosages of carbonyl sulfide were treated for 4 hours, and the mortality was investigated after 24 hours of treatment. Nymphal stage of M. persicae was completely controlled at more than 20 mg/L dosage, and adult stage showed 95.8% mortality at 80 mg/L dosage. The LC50 of M. persicae was 7.314mg/L for nymph and 26.117mg/L for adult stage. Egg stage of T. urticae showed 91.2% mortality when treated with 100mg/L carbonyl sulfide, and nymph and adult stage showed 100% and 94.1% mortality at 8mg/L and 80mg/L, respectively. The LC50 of T. urticae was 73.110mg/L for egg, 2.818mg/L for nymph and 12.054mg/L for adult stage.

The susceptibility of three fumigants, methyl bromide, ethyl formate and phosphine, and concurrent treatment of ethyl formate and phosphine were tested on Lasioderma serricorne. Susceptibility assessment were performed by treating 5 to 6 initial dosage on every growth stages of L. serricorne. The LCT50 of methyl bromide was 13.896mg h/L for egg, 36.038mg h/L for late larvae, 25.172mg h/L for pupae and 21.758mg h/ L for adult, respectively. The LCT50 of phosphine was 0.317mg h/L for egg, 0.649mg h/L for late larvae, 3.748mg h/L for pupae and 0.703mg h/L for adult, respectively. In case of ethyl formate, the LCT50 was 43.657mg h/L for egg, 137.606mg h/L for late larvae, 72.676mg h/L for pupae and 52.951mg h/L for adult, respectively. Concurrent treatment of ethyl formate and phosphine was performed by treating 5 to 6 initial dosage of ethyl formate with 0.5 mg/L phosphine for 4 hours on every growth stages of L. serricorne. The LCT50 of ethyl formate concurrent treatment was 13.746mg h/L for egg, 8.156mg h/L for late larvae, 27.087mg h/L for pupae and 11.353mg h/L for adult, respectively, and these results indicate that concurrent treatment can control pest with lower dosage and shorter period. Sorption rates and ventilation periods of each fumigants were also calculated for efficacy and safety

The existing ethyl formate fumigant is carbon dioxide (CO2) mixed liquified gas in metal cylinder, but this product type costs a lot to manufacture, translate and maintain cylinder. To supplement these problems, we have developed a new ethyl formate fumigation technique with nitrogen (N2) carrier. We assessed the susceptibility of mealy bugs, the most frequently detected pests in imported banana, and phytotoxicity of banana fruits. Ethyl formate and nitrogen were concurrently treated on citrus mealybug, one of the most resistant mealybug to fumigant, and ethyl formate was treated with LC50 product of independent treatment dosage. Nitrogen was treated with 7 dosages from 79% to 95% concentration. Phytotoxicity of banana was assessed by treating EF 35 mg/L with N2 79% for 14 days, and color, sugar contents and loss of weight were measured. EF with N2 treatment showed more than 50% of mortality on every growth stages, and there was no significant difference between control and treatment banana fruits. These results indicate that concurrent treatment of EF and N2 can be used to control mealybug in banana fruits.

Spotted wing drosophila, Drosophila suzukii, is an important pest of grape and strawberry because it lays egg inside fruit by damaging fruit surface. Recently, D. suzukii has been widely spreaded and causes several problems, so many countries include Australia designated D. suzukii as an important quarantine pest. Because of this, Korean farmers have trouble to export strawberry. In this study, we tested ethyl formate and phosphine to control D. suzukii, and also tested concurrent treatment of ethyl formate and phosphine to reduce phytotoxicity and enhance efficacy. When treated 35g/m3 of ethyl formate for 4 hours, mortality of egg, larvae, pupae and adult stages of D. suzukii was 22.2%, 21.1%, 19.2% and 28.3%, respectively. When treated 1g/m3 of phosphine for 24 hours, all stages of D. suzukii was completely controlled, but caused phytotoxic effect on strawberry. When treated with 35g/m3 of ethyl formate and 1g/m3 of phosphine concurrently for 4 hours, efficacy has been increased with less phytotoxicity than separate treatment. This result indicates that concurrent treatment enhanced efficacy with less phytotoxicity.

This study investigated the fumigant activity of phosphine (PH3) on 2 kinds of mealybug (Pseudococcus longispinus and P. orchidicola (Hemiptera: Pseudococcidae)) adults and nymphs. All of the two mealybugs adults showed higher LCT99 values than nymphs, and P. longispinus showed higher tolerance than P. orchidicola in a 12 L desiccator. The absorption of phosphine on 13 nursery plants showed 12.2~41.5% difference depending on the plant. All of the mealybugs treated with phosphine 2 mg/L in 0.5 m3 fumigation chamber for 4 h showed 100% fumigant activity, except P. longispinus adult (approximately 90% at bottom part). However, when the exposure time was increased to 24 h, all of them showed 100% mortality. In the treatment of 10 m3 container, the 24 h treatment of phosphine showed 100% mortality to P. longispinus and P. orchidicola adults and nymphs. In all the experiments, no phytotoxicity of phosphine observed on 13 plants until 1 month after treatment.

2017년 경북지역은 약 700ha 이상의 면적에서 미국선녀벌레의 피해를 입었다. 그 중 600ha의 피해면적이 떫은감 주요 생산지인 청도군에서 발생하였다. 미국선녀벌레의 효율적인 방제를 위해 2018년 5월 상순에 침투이행성 약제를 토양에 처리하여 약충이 부화하기 전감나무 수체 내 약제를 이행시켜 방제효과를 조사하였다. 토양입제처리의 방제효과 조사를 위하여 토양입제 단독처리(5월 상순), 경엽살포 단독처리(6월 중순), 토양입제(5월 상순) 및 경엽살포(6월 중순) 체계처리를 비교하였다. 조사결과 토양입제 단독처리 시 약제처리 후 약 70일 이상 90%이상의 방제효과가 지속되었고, 경엽살포 단독처리 시 약제처리 후 약 2주 동안 90%이상의 방제효과를 보인 뒤 방제효과가 감소하였다. 또한 토양입제 및 경엽살포 체계처리 시 약제처리 후 약 70일 동안 95%이상의 높은 방제효과를 보였다.

This study investigated number of eggs, hatch rate, toxicities and LT (lethal time) values of Culex pipiens and Aedes albopictus using Aquatain™(Aqua mosquito film). Aquatain™ is a covering agent applied on the surface of water for the control of larva and pupa of mosquito. It forms molecule layer on the surface of the water to lower the surface tension of the water, to prevent flooding of the larva of the mosquito larvae, or to suffocate by obstructing breathing. Cx. pipiens and Ae. albopictus larvae observed 99.9% and 1% larvicidal effect after 24h, respectively. However, both mosquito pupae were showed 100% mortality after 24 h. The AMF™ was treated with three doses (0.5, 1, 2 folds) to observe the LT value in larvae and pupae stages of Cx. pipiens and Ae. albopictus. The LT values of Ae. albopictus pupa was similar regardless of dose, but the LT value of Cx. pipiens pupa decreased as the dose increased. However, Ae. albopictus larvae showed 18.6 folds longer LT90 time than Cx. pipiens larvae. Both species mosquito showed statistically significant differences in the number of eggs laid and hatch rate at recommended dose. Therefore, Aquatain AMF™ may be used to control mosquitoes, although the activity varies depending on the species of mosquito.

농업용 무인멀티콥터를 활용한 방제면적은 수도작은 물론 밭작물에서도 방제 범위가 확대되고 있다. 밭작물은 작물의 형태가 다양하여 비행속도, 살포높이 등을 최적화하는 연구가 필요하다. 본 연구에서는 배추, 대파, 고추에서 발생하는 나방류에 대하여 무인멀티콥터의 살포 높이에 따른 방제효과를 확인하였다. 살포된 약제가 작물에 부착되는 정도를 조사한 결과, 배추는 2m, 대파는 3~4m, 고추는 모든 높이에서 비슷한 부착정도를 보였지만, 전체적으로 부착량이 적고 불균일 하였다. 살포 높이별 방제효과는 작물별로 각각 배추(9~10엽기)는 2m높이, 고추(약 1.2m)는 2~3m, 대파(약 60cm)는 2, 3, 4m 각각 비등한 방제효과를 보였다. 각각의 작물모두 경엽처리 대비 약효가 미흡하였으며, 고추는 4m높이 살포시 방제효과가 현저히 낮았다.

Thrips is one of the serious insect pests in many economic crops, in which general managements rely mainly on chemical insecticides. However, the overuse of chemicals led to the development of insect resistance and environmental residual issues. Therefore, thrips management requires the consideration of alternative strategies which are less harmful to the environment and working on different target points. In this work, we isolated entomopathogenic fungi from soil, and identified them with morphological and molecular biology methods, followed by a preliminary virulence assay against Tenebrio molitor larvae. Selected fungal isolates were adjusted to 1×107 conidia/ml for an indoor virulence assay against thrips adults, and highly virulent isolates were added to a thrip-pathogenic fungal library. Biological characteristics of efficacious isolates were investigated comparing to a previously commercialized fungal isolate. This entomopathogenic fungal library could be used as a valuable resource for developing effective strains to control thrips in agricultural fields.

Japanese pine sawyer beetle, Monochamus alternatus Hope (Coleoptera: Cerambycidae) is considered as a serious pest in pine trees. To develop an eco-friendly strategy to manage this forest insect, we collected entomopathogenic fungi from Korean soil and assessed their virulence against the adults of the insect in laboratory conditions. As a result, two isolates with conidial suspension (1.0×107conidia/ml), showed 87% and 90% mortality 12 days after fungal treatment, respectively. We assessed the potential of the fungi-derived destruxin and protease as additives to the fungal isolates, and they showed insecticidal activity via feeding and spraying treatments. Finally, we produced fungal conidia in massive solid cultures and formulated wettable powders, and now studying optimal conditions of oil-based formulation with two isolates. Based on these results, we are evaluating the control efficacy of the fungal agents against M. alternatus in field conditions.

Pine tree, a dominant species in the flora of Korea is the most beloved tree in Korea. However, recent outbreak of pine wilt disease caused by the pine wood nematode (PWN) Bursaphelenchus xylophilus threatens the vegetation of Pinus species seriously. Furthermore, Pinus densiflora and P. thunbergii, the predominant species in Korea forest are highly susceptible to PWN. Therefore, there has been an urgent demand for the development of a new nematocidal compounds to control PWN, which spurred the national research for the development of new compounds. To find novel sources for nematocidal agents, we used various plant resources for the development. In addition to the foreign plant extracts themselves, we also used the extracts of endophytes composed of over 300 endophytic fungi and 1,000 endophytic bacteria from plants which was reported to contain nematocidal activity. Several extracts of endophytes and plant extracts contained strong nematocidal activity, and the resources are analyzed to identify the active nematocidal compounds. These integrated approach of finding effective nematocidal compounds from plants could be a novel way to elucidate the sources for brand-new nematocidal agents.

There has been a heated discussion worldwide over tourist deviances that disrupt lives of local residents and cause damage to companies, city authorities, and the natural environment. Previous studies primarily turn to discrepancies in the cultural and educational background between tourists and local residents to explain such phenomena. Nonetheless, the possibility of people inclining to misbehave simply because they are away from home has rarely been investigated. In this study, we seek to examine factors rooted in the nature of tourism that are accountable for such phenomena. According to the definition by UNWTO (1995), one of the key characteristics of tourism is the displacement of usual environment. Tourism, therefore, is inevitably associated with surroundings of unacquainted others residing in the unfamiliar environment. Following the social control paradigm, previous studies have revealed that people are more likely to enforce social control on in-group members than on out-group members (Nugier, Chekroun, Pierre & Niedenthal, 2009). We further propose that psychological closeness between people and surrounding others would have an impact on their expectation to receive others’ social contrail and consequently their intention to engage in the counternormative behavior. Using an experimental study, we found that participants in the travel condition, compared with those in the home condition, feel less close to surrounding others and are more likely to misbehave. Such effect is mediated by the perceived social control. Implications for organization and companies in the tourism sector are drawn to prevent the spread of tourist misbehavior. Limitations and future directions would also be discussed.

Reports indicate that in 2017, social commerce had become a 20 billion dollar industry. Given the developing world’s fatigue with social media, social commerce growth will likely be fueled by consumers from developing economies. While literature has investigated social commerce in the context of established brands in developed economies (e.g. Kim and Ko, 2012), it cannot yet explain consumers’ engagement with the uniqueness of social media commerce in developing economies. Social commerce in Southeast Asian economies are largely conducted amongst individuals or micro businesses. Since social media platforms largely do not provide commerce security nor support, consumers are more vulnerable to fraudulent practices. What factors motivate these purchases despite such risks? This study offers insights into how consumers’ motivated reasoning influences their willingness to purchase over social media. We focus on the social media store’s ease of use and perceived security as antecedents of trust. Specifically, we argue that perceiving a lack of ability to purchase from other channels would induce higher trust towards a social media store, despite low perceptions of ease and security of transaction. Data was collected from 224 Indonesian social media users who have been exposed to social media stores on Instagram. The findings suggest that when consumers perceive high control of how they could obtain desired goods, trust becomes a logical function of the perceived safety and ease of use of the shops. However, under low perceived control, consumers display high trust in social media shops despite not being convinced that they are safe nor easy to use. The findings extend our understanding about the antecedents of value creation in social commerce (Stephen and Toubia, 2010). Our results enrich prior literature by showing how motivated reasoning leads to biases in judgment to be in favor of desired goals (Blanton and Gerrard, 1997), and extends it in the novel context of social media commerce. Furthermore, by incorporating the literature on perceived behavioral control and motivated reasoning, the current study provides important empirical evidence for the presence of perceived control over alternate channels as a significant driver for trust towards social media shops. The current research also has a number of implications for social commerce providers in developing economies. This study shows that it is advantageous for managers to cultivate trust using interactivity and reliability to elicit a sense of security and ease of use. However, our findings also offers a caution for firms to not be lulled into a false sense of comfort by taking consumers’ trust at face value.

미포장충류(Nosema spp. (NS))는 양봉꿀벌에 심각한 문제를 야기시키는 기생충으로 효과적인 방제물질의 선발이 무엇보다 중요하다. 본 연구는 노제마병과 기타 꿀벌의 발생유행시기의 구명과 더불어 3가지 노제마병 방제물질(M1 = 벌꿀희석의 레몬쥬스; M2 = 설탕시럽 혼합의 카모마일 추출물; M3 = 설탕시럽 혼합의 항생물질 스트리베트)을 평가하고자 수행하였다. 꿀벌 성충과 유충집단의 질병 유행시기를 년간 조사하였으며, 야외 및 실험실 조건에서 노제마병에 대한 M1, M2, M3의 효과를 평가하였다. 조사결과 극소수의 꿀벌 성충과 유충 질병이 발견되었다. 노제마 병은 겨울과 봄 기간 저온과 고습조건에서 검출되었다. 포장실험에서 M2는 36.66%까지 발병억제 능력을 보였으며, 반면M3는 23.33%, M1는 13.33%의 억제효과를 보였다. 실내실험에서 M2가 방제효과가 가장 좋았고, 그 다음 M1와 M3 이었다. 3가지 방제물질은 병에 감염된 꿀벌성충의 생존력을 크게 높이는 것으로 나타났다. 본 연구는 노제마병 방제를 위한 천연물질로 카모마일의 잠재적 방제효과를 제시하고 있다.

벼 이앙기별 인산에 의한 논조류 발생과 제초제에 의한 방제 효과는 다음과 같다. 1. 단작 및 이모작 벼 재배지에서 총출현 종수는 61종으로 녹조류 34종, 규조류 16종, 유글레나 7종, 그리고 남조류 4종이 발생하였고, 녹조류, 규조류는 이모작지가 많았고, 유글레나는 같았으며 남조류는 단작이 많았다. 2. 인산을 이앙전에 50%처리하고 분얼기에 50% 시비하였을 때 총인이 0.06 mg L-1로 가장 높았고, 조류 발생량도 무인산 대비 6월 6일 이앙한 구에서 14.8 mg 20 ml-1으로 3배 이상, 6월 20일에 이앙한 구에서 9.8 mg 20 ml-1 2배 이상 증가하였다. 3. 벼 생육단계별 분얼기, 유수형성기, 그리고 수잉기의 토양 인산의 함량은 관행 및 인산분시별로 유수형성기가 인산의 함량이 116.5~191.8 mg kg-1으로 가장 높은 경향이었으며 무 처리구에서는 15.5~29.1 mg kg-1로 낮았다. 이앙시기별로는 이앙이 빠를수록 높은 경향이었으며, 인산분시별로는 관행에 비해 분시하였을 때 높은 경향을 보였다. 4. 클로로필-a 함량은 6월 6일 이앙한 구에서는 제초제 처리 후 7일에 가장 낮은 6.3 mg m-3 이고, 7월 상순에 무처리구에서 75.8 mg m-3 로 가장 높았다. 6월 20일 이앙한 구에서는 제초제 처리후 7일에 가장 높은 경향이었으며 제초제 처리 후 14일과 21일은 감소하는 경향이었다 5. 논조류 억제율은 quinoclamine이 단작에서 59.2%, 이모 작에는 44.4%로 가장 높았으며, 다음으로 bromobutide + imazosulfuron + pyraclonil > benzobicyclon + mefenacet + peno xsulam >무처리 순이었다.