Riptortus pedestris (F.) inflict losses on a wide range of crop plants. Biological control is an alternative approach to reduce the bean bug population. Scelionid Gryon japonicum (Ashmead) and Encyrtid Ooencyrtus nezarae Ishii are the major egg parasitoids of R. pedestris. The aggregation pheromone of R. pedestris serves as a kairomone to its egg parasitoids. A new tool was developed using aggregation pheromone in a trap which attracts both con-specific bugs and the parasitoids. Non viable host eggs were added with the trap so as to provide resource for the attracted parastioids to multiply. Several studies were conducted to develop this new tool for trapping of the bugs and enhancing parasitism simultaneously. Aggregation pheromone trap added with host eggs was found to increase temporal parasitism in field by 44% compared to the parasitism without host eggs. Higher parasitism (up to 91%) was found in the sites where aggregation pheromone trap added with host eggs was installed compared to control sites. In order to improve this tool, a new device with twelve sections to hold eggs and to be attached to the pheromone trap was designed to provide maximum exposure of the eggs to the parasitoids and to minimize the competition among the parasitoids. Parasitism and number of female R. pedestris trapped in new device attached trap were higher compared to the conventional. With better performance in trapping R. pedestris and enhancing parasitism, the tool would serve as an IPM technique that targets killing the pest and enhancing activity of the pest’s natural enemy simultaneously.

본 연구는 영상 분석을 활용하여 비접촉 방식으로 난백 높이를 측정하여 저장 품질 변화를 측정하는 알고리즘을 개발을 시도하였다. 본 연구에서는 계란의 영상 추출 알고리즘 영상분석을 통하여 난백높이를 비 접촉 방식으로 측정할 수 있었다. 이를 통한 저장 기간별 농후난백의 퍼짐 측정과 Haugh unit 및 무게 감소율, pH, 점도의 결과를 측정하였다. 저장 기간별 퍼짐 측정 및 Haugh unit은 저장 초기에 0-5일차 구간에서 가장 급격한 변화를 보였다. 이는 저장 초기에 농후 난백의 수양화가 가장 빠른 속도로 진행됨에 따라서 농후 난백의 높이가 급격히 변하여 신선도 지표로 사용하는 Haugh unit에 영향을 미쳤다. 저장 기간별 무게 감소율은 0.39%로서 일정한 감소율을 나타내었다. 최종 저장 기간 30일 동안 초기 무게를 기준으로 하여 30일 차에서는 약 11.5%의 무게가 감소하였다. 이러한 무게 감소는 계란 내부에서 발생하는 호흡에 의한 수분과 CO2 유출로 인한 것이다. 저장 기간별 pH의 변화는 난백에서 저장 초기에 급격하게 증가하였다. 이는 계란 내부의 높은 농도의 CO2가 외부 공기의 CO2 간의 극심한 농도 차로 인하여 유출 속도가 빨랐지만 저장 기간이 증가함에 따라 평형 상태에 도달함으로써 pH의 변화가 미미하였다. 이는 농후 난백의 높이 데이터에서의 패턴과 유사하며, 이를 통하여 pH의 변화가 농후 난백 내의 겔 구조물인 ovomuchin-lysozyme의 결합체의 결합력에 영향을 미침으로서 결합력이 낮아져 나타나는 현상임을 확인할 수 있었다. 저장 기간별 난황의 점도의 변화는 기본적으로 Newtonian 모델에 대하여 R2 값이 0.95 이상을 나타내었다. 또한 저장 기간이 증가함에 따라 난황의 점도가 감소하였는데, 이는 난황과 난백간의 부위별 수분 함량의 차이로 인하여 난백의 수분이 난황으로 이동하여 이로 인해 저장 기간이 증가함에 따라 점도가 감소하는 것을 확인하였다.

넙치, Paralichthys olivaceus 수정란의 부화율을 이용하여 중금속(Pb, Cr, As)의 독성 영향을 조사하였다. Pb, Cr, 및 As (0, 10, 100, 500, 1,000, 2,500, 5,000 ppb)에 수정란을 48 h 노출시킨 후, 정상 부화율을 백분율로 나타내었다. 중금속을 포함하지 않는 대조구에서는 정상 부화율이 80% 이상을 나타냈으나, 중금속 농도가 증가할수록 정상 부화율은 급격히 감소하였다. 정상 부화율은 Pb, Cr, 및 As에 대해 농도 의존적으로 감소하였으며, 각각 100, 100, 500 ppb 이상의 농도에서 유의한 차이를 나타내었다. P. olivaceus의 정상 부화율에 대한 Pb, Cr 및 As의 반수영향농도(EC50)를 이용한 독성은 Cr¤As¤Pb 순으로 나타났다. Pb와 As의 NOEC와 LOEC 각각 100 ppb와 500 ppb로 유사한 값을 나타냈으며, Cr에 대한 NOEC는 10 ppb, LOEC는 100 ppb를 나타내었다. 이들 결과로부터 자연생태계 내에서 Pb과 As의 농도는 100 ppb, Cr 농도는 10 ppb를 초과할 경우 P. olivaceus 수정란의 정상 부화율은 독성 영향이 나타날 것으로 판단된다. 본 연구 결과를 바탕으로, P. olivaceus의 정상 부화율을 이용한 생물학적 평가방법은 중금속과 같은 유해물질에 대한 해양생태계의 영향을 판단하기 위한 시험방법으로 유용하게 이용될 수 있을 것으로 판단된다.

Sparganosis is a rare parasitic disease caused by the infection of plerocercoid tapeworm larvae of the genus Spirometra. Up to date many cases of oral sparganosis had been diagnosed from biopsy specimens in Korea, however, in this study a 14 years old male showed an oral sparganosis in his buccal nodule producing its eggs, which were extruded through the ulcerated surface of buccal nodule. In the cytological observation for the pus‐like exudates many ovoid parasite eggs were found with a lot of inflammatory cells, which were mostly composed of eosinophilic polymorphonuclear leukocytes (PMNs). The eggs were measured about 50x50x80 μm, and had an operculum without opercular shoulder. In the subsequent biopsy examination the buccal nodule disclosed a diffuse granulomatous lesion with tunnel‐like spaces containing eosinophilic materials of parasite tegument, also infiltrated with a lot of eosinophilic PMNs. Therefore, we diagnosed it oral sparganosis producing its eggs with the characteristic features of sparganum granuloma in the cytological and histological observations, and also suggested that the cytological finding of parasitic eggs would be helpful to confirm the parasitic infection of sparganum matured enough to produce its eggs.

This study developed a rapid egg-salting method using a temperature change in NaCl solution under pressure. The permeation effects(PEs) of NaCl into eggs at ambient pressure were analyzed 1) after soaking them in 20, 30, or 40%(w/v) NaCl solution at 50℃ and 2) after soaking in 20～40% concentrations(w/v) of NaCl solution at 4℃ immediately after soaking at 50°C for 1 hr(temperature change method; TCM). Under permeation conditions(40% NaCl solution with TCM), the PE of NaCl into eggs at various pressures(4.0～7.0 MPa) was determined. The PE improved with increasing NaCl concentration and pressure. In 40%(w/v) NaCl solution, the PE was more rapid with TCM(0.70% for 2 hr) than without TCM(0.60% for 2 hr). At 7.0 MPa pressure, the PE was more rapid with TCM(1.66% for 15 min) than without TCM(1.40% for 15 min). These results suggest that the TCM-induced contraction of the egg membrane improved the PE. Therefore, we believe that the development of a rapid salting method for seasoning eggs is possible with the TCM.

넙치(Paralichthys olivaceus) 수정란의 부화율에 대한 중금속(Cd, Cu, Zn)의 급성독성을 조사하였다. Cd, Cu 및 Zn (0, 10, 100, 500, 1000, 2500, 5000 ppb)에 수정란을 48h 노출시킨 후, 정상 부화율을 백분율로 나타내었다. Cd, Cu 및 Zn을 포함하지 않는 대조구에서는 정상 부화율이 80% 이상을 나타냈으나, 중금속 농도가 증가할수록 정상 부화율은 급격히 감소하였다. 정상 부화율은 Cd, Cu 및 Zn에 대해 농도 의존적으로 감소하였으며, 각각 1000, 100, 100 ppb 이상의 농도에서 유의적이 차이를 나타내었다. P. olivaceus의 정상 부화율에 대한 Cd, Cu 및 Zn의 반수영향농도(EC50)를 이용한 독성은 Zn¤Cu¤Cd 순으로 강한 것으로 나타났으며, 이들 중금속에 대한 EC50는 각각 584, 1015, 1282 ppb를 나타내었다. Cd에 대한 NOEC는 500 ppb를 나타냈고 LOEC는 500 ppb를 나타내었다. Cu와 Zn의 NOEC와 LOEC 각각 100 ppb와 500 ppb로 유사한 값을 나타내었다. NOEC와 LOEC 결과로부터 자연생태계 내에서 Cu와 Zn 농도는 100 ppb, Cd 농도는 500 ppb를 초과할 경우 P. olivaceus 수정란의 정상 부화율은 감소할 것으로 판단된다. 본 연구결과를 바탕으로, P. olivaceus의 정상 부화율을 이용한 생물학적 시험은 중금속과 같은 유해물질에 대한 해양생태계의 영향을 판단하기 위한 시험방법으로 유용하게 이용될 수 있을 것으로 판단된다.

Aggregation pheromone of Riptortus pedestris (Fabricius) (Hemiptera: Alydidae) has kairomonal effect on its egg parasitoids. Thus, inclusion of non-viable host eggs of R. pedestris to aggregation pheromone trap was suggested to propagate parasitoids attracted in the trap. In this study, spatial and temporal distribution of egg parasitoids were investigated in sesame fields in Songcheon, Andong where aggregation pheromone traps were installed with non-viable host eggs. Parasitism changes were assessed after collecting non-viable host eggs released at distances of 8, 16, 24, and 32 m from the trap. Higher egg parasitism and adult emergence was found up to 16 m from the point of release. Parasitism increased over time, but decreased with distance. For the comparison of change in temporal parasitism, traps were installed without host eggs in another sesame field. Parasitism rate in sesame field without host eggs increased by 13%, whereas, in the field with host eggs, the parasitism increased up to 44%. These findings suggest that host eggs attached to the pheromone traps help the parasitoids propagate and disperse.

Periodical release of non-viable refrigerated eggs of Riptortus pedestris (Fabricius) has been found to enhance field parasitism level in soybean fields. However, optimum refrigeration conditions required for the eggs in order to preserve its quality to ensure effective level of parasitism for a longer period has been rarely reported. We assessed optimum environment condition for refrigeration of the eggs using three different temperatures (2, 6, and 10℃) and relative humidities (RH) (high, medium and low). Eggs of R. pedestris were refrigerated at nine combinations of temperature and relative humidity for 30 consecutive days. Those eggs were taken out and after 8 days, mated female Ooencyrtus nezarae Ishii (Hymenoptera: Encyrtidae) were individually exposed to the eggs, and their development, emergence, and sex ratio were examined. Number of eggs parasitized was highest (5.9) on eggs stored at 6℃ and high RH. Significantly higher male proportion was recorded in the eggs stored at 10℃. However, RH had no effect on the sex ratio. For both male and female, development time was the least on host eggs stored at 2℃ and high RH. Adult emergence was recorded highest from the eggs stored at 2℃ followed by 6℃ and at high RH. In conclusion, eggs refrigerated below 6℃ at high RH condition maintained better quality of R. pedestris eggs for the parasitization by O. nezarae.

Cold hardiness is an important trait for insects, that enables them to survive during the winter and develop in the next season, and to extend their range. Lycorma delicatula (White), which became an important sporadic pest in grapevines and some other fruit trees, has spread rapidly to the most of regions in South Korea. This study was conducted to determine the cold hardiness of overwintered L. delicatula eggs according to geographical variation. We collected overwintering eggs in the five sites, Chuncheon, Suwon, Yeongdong, Gunsan, Daegu, on 22~25th Feb. in 2011. We treated eggs to combinations of different temperatures (-15℃, -20℃, -25℃) and exposure time (12hr, 24hr, 3days, 5days, 7days) after chilling them for 24~26 days at 5℃. And then, they were kept in the room temperature. We only analysed three sites of Suwon, Gunsan and Daegu, because of very low hatching rate at Chuncheon and Yeongdong. There were significant effects of time (F=36.97 d.f.=4 P<0.0001), sites (F=17.28 d.f.=2 P<0.0001), and the interaction of time and temperature (F=5.77 d.f.=5 P<0.0001) at -15℃. At -20℃, eggs hatched only at 12hr and 24hr of exposure treatment. All eggs treated at -25℃ failed to hatch. It appears that -25℃ is around the critical temperature.

Paratlanticus ussuriensis enter prolonged diapause at an egg stage. Environmental conditions, such as temperature, can modify the diapause duration at initial diapause. Eggs enter initial diapause at 20℃, but continued early embryonic development at 30℃. Final diapause at a fully developed embryonic stage is obligatory regardless of temperature conditions. To determine temperature effects on diapause mechanism of P. ussuriensis eggs, we compared weights, DNA and RNA amounts of eggs incubated at either 20℃ or 30℃ for 50 days after oviposition. Both egg weight and total amount of DNA were constant at 20℃ but gradually increased at 30℃. However, total RNA level was rapidly increased at 15 days-old eggs at 30℃ and maintained high levels during further period whereas its level was constant at 20℃. In addition, we identified three heat shock protein 70 (hsp70a, hap70b, hsp70c) genes of P. ussuriensis and determined those expression levels at different temperature conditions. The levels of hsp70a and hsp70b was not detectable until 20 days after oviposition at both temperature conditions, but highly increased at 50 and 60 days when incubated at 30℃. In contrast, hsp70c level was rapidly peaked at 20 days after oviposition, which is the time of initial diapause entrance. Our results suggest that high temperature breakdown initial diapause and a certain hsp gene, such as hsp70c, may involve in the initial diapause mechanism of P. ussuriensis eggs.

The parasitism, development time, hatchability, and progeny production of Trichogramma chilonis(TC) females developed in eggs of Helicoverpa assulta (HAs), Cadra cautella (CC), and Helicoverpa armigera (HAr), repectively, were compared with those developed in reciprocal eggs at constant temperatures of 25±2℃ and relative humidity of 50～70% under 16L-8D. Developmental performances of TC reared in each of the three hosts on the following hosts(host tested) appeared differently, and were affected most by the size of the proceeding hosts and test host. Among the parameters parasitism and progeny production were affected more than others. Parasitism was significantly different between the treatments, lowest in CC-HAr(10.1±2.05%) and highest in HAr-HAs(47.0±2.09%), and the hatchability showed similar pattern. Development time as well was shortest in the CC-HAr where previous host is smallest and test host is biggest. The highest number of progeny production of TC was observed in HAr-HAs(93.9±6.87 wasps), and the lowest was CC-HAs(18.4±6.36 wasps).

The diapause duration P. ussuriensis eggs is known to either one year or prolonged to additional years. This complex life cycle is mainly caused by the interruption at two embryonic stages: early stage (initial diapause) and fully developed late stage (final diapause). The environmental cues, such as temperature, is critical to determine the diapause duration but the precise diapause mechanism of P. ussuriensis eggs is unclear. We demonstrated temperature effects on the entrance of initial diapause. Newly oviposited eggs were incubated at two temperature conditions (20℃and 30℃) for 60 days. When eggs were incubated at 20℃, egg weights were not significantly changed, but at 30℃ those were gradually increased to 1.5 times for 50 days. Genomic DNA contents of eggs were similarly increased at 30℃. Total RNA contents at 30℃ were highly increased from the 15-days-old but not at 20℃. In addition, we further analysed expression levels of two heat shock protein 70 (hsp70a, hap70b) genes during embryonic development. Our results suggest that initial diapause occurred between 10 and 15 days after oviposition and its entrance was blocked by high temperature incubation.

We studied to develop a forecasting model to predict the hatching time of overwintered eggs of Lycorma delicatula. We collected overwintering egg masses on 1st February, 17th February and 4th March. After chilling them at 5℃ for 15 days, development of eggs was investigated at six constant temperature (35, 31, 27, 23, 19, 15℃). The hatching rate of egg was highest at 23℃ (87.88±19.32%) followed by 19℃ (87.71±21.47%), 27℃ (75.96±24.82%), and 31℃ (30.92±24.81%). Eggs did not survive at 35℃. The developmental duration of eggs was 39.47±2.24, 22.96±3.25, 17.56±1.58 and 12.15±6.29, at 19, 23, 27 and 31℃, respectively. The egg developmental rate was described with a linear model (eq. Y=0.0034X-0.0364 (r=0.9649)) between 19℃ and 31℃. The lower developmental threshold temperature was 10.71℃ and effective accumulated temperature for egg development was 286.40 Degree days.

Riptortus pedestris (Fabricius) (Hemiptera: Alydidae) causes losses in several crops in Korea. Release of non-viable refrigerated eggs of R. pedestris is known to enhance natural parasitism by Ooencyrtus nezarae Ishii (Hymenoptera: Encyrtidae) and Gryon japonicum (Ashmead) (Hymenoptera: Scelionidae) in soybean fields. In this study, we conducted an experiment of cage-exclusion design to verify the former results in more manipulative approach in a soybean field. Agakong field (45×26 m2) located at Songcheon, Andong was divided into 15 plots (10×6 m2) with each experimental arena of 3×2 m2 in the center. There were three treatments: (1) release of refrigerated eggs of R. pedestris, (2) release of refrigerated eggs with one time spray of thiamethoxam, and (3) untreated control. A fine mesh cloth with iron poles was used to encircle the arenas. Refrigerated eggs of R. pedestris were released (100/arena) twice before sampling. One-day old eggs of R. pedestris were released (60/arena) in all the experimental arenas at an interval of 6 days, and 30 eggs from each were collected to record parasitism. We found no significant difference in the eggs and nymphs population of R. pedestris among the treatments. However, adult density was significantly reduced in the treated plots during final two sampling days compared to the control. We found significantly higher parasitism by G. japonicum on the eggs collected from treated plots (9-25%) compared to the control plots (1-9%). It is verified that releasing non-viable eggs of R. pedestris help to enhance natural parasitism in soybean field.

A new species of Closterocerus (Hymenoptera: Eulophidae: Entedoninae) is described from South Korea. The species is reported for the first time as an egg parasitoid of Pachynematus itoi Okutani (Hymenoptera: Tenthredinidae), of which recent sudden outbreak caused severe damage in larch forests. In total 61 species in Chalcidoidea are recorded as primary parasitoids of various tenthredinid sawflies in the Palaearctic area. However, no chalcidoid parasitoids have previously been recorded from P. itoi. The genus Closterocerus is cosmopolitan in distribution, and with an extremely wide host range from Symphyta, leaf-mining and gall-inducing insects to scale insects and plant lice. In Korea, one species of Closterocerus, three Chrysonotomyia, two Desmatocharis, one Neochrysocharis and one Teleopterus were known; most of them, except Chrysonotomyia sudoensis Paik, now are placed under Closterocerus. The new species is compared with 13 other species of Closterocerus that are known from the Far East.

During the last several years, the population of the ussur brown katydid, Paratlanticus ussuriensis has been highly increased at mountain-side orchards in Youngdong province in Korea. Nymphs and adults emerged one time per year from early May to August and cause a serious demage on the crop production. Adults oviposit eggs from July to September under the ground and eggs overwinter at diapause stage. However, the diapause duration P. ussuriensis is known to either one year or prolonged to additional years. The environmental cues, such as temperature, could be a critical to determine the diapause duration but the precise diapause mechanism of P. ussuriensis eggs is unclear. We demonstrated to determine the stage of diapause initiation during embryogenesis. Newly oviposited eggs were incubated for 60 days at two temperature conditions (20℃and 30℃). When the eggs were incubated at 20℃ those weights were not changed, but when they incubated at 30℃ those were increased from 15-days-old. Total RNA contents of eggs incubated at 30℃ were highly increased from the 15-days-old when they compared with those of eggs incubated at 20℃. In addition, total DNA contents of eggs were greatly higher when they incubated at 30℃. Our results suggest that early embryonic development was sensitive to high temperature and it was stimulated at 15-days-old. To determine the temperature response of embryonic development at molecular level we identified heat shock protein 70 (hsp70) gene of P. ussuriensis. Further analysis would conduct the gene expression rate of diapausing eggs on different temperature conditions by using real time RT-PCR technique and determine the molecular characteristics of P. ussuriensis egg diapause.

Rearing media were selected for the production of sterile larvae of greenbottle blowfly, Phaenicia (=Lucilia) sericata (Meigen) which is widely used in maggot therapy. Eight media available in the market were used in this study. Egg hatchability was not different among the media. Survivorship of the larvae was higher in blood agar (BA), sabouraud dextrose agar, and brucella blood agar than the others. A higher content (20~40%) of sheep blood in BA and chocolate agar increased the survivorship of larvae. The eggs and the early 3rd larvae could be stored for 12 days at 8℃ and for 15 days at 6℃ without decrease in hatchability and larval survivorship, respectively.

This experiment was conducted to prevent the contamination of parasite egg on vegetables for supporting safety production of leafy vegetables. After the chinese cabbages and soil samples were collected at 5 cities of Gyeonggido during 2007-2008, the existence of parasite egg was surveyed. All collected samples had no parasite egg, so the chinese cabbages produced in Gyeonggi area were assumed parasite egg-free. To examine the characteristics of parasite eggs, the pig roundworms, Ascaris suum, were collected from the intestine of infected pig and the parasite eggs were collected from the uterus of A. suum. The eggs of A. suum developed to embryonated eggs, which can infect humans, in 20℃-30℃, but not 15℃ and 35℃, when cultured at different temperatures. The eggs developed to embryonated eggs after drying for 0-24h when cultured after different drying times. Effect of soakage different salt solution and times showed that the eggs developed to embryonated eggs after soakage at 0-25% salt solution for 0-24h. For eliminating the parasite eggs attached leafy vegetables, it was efficient to soak at salt solution for 5 minutes and washing 5 times with water.