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Although campylobacteriosis caused by Campylobacter jejuni and Campylobacter coli has been increasingly reported worldwide owing to the consumption of contaminated poultry and fresh produce, the current detection protocols are not selective enough to inhibit unspecific microbes other than these pathogens. Five antibiotics were separately added to Bolton broth, and the survival rates of 18 Campylobacter spp. and 79 non-Campylobacter spp. were evaluated. The survival rate of the non-Campylobacter spp. was the lowest in Bolton broth with rifampin (6.3%), followed by cefsulodin (12.7%), novobiocin (16.5%), and potassium tellurite and sulfamethozaxole (both 17.7%). Also the most effective concentration of rifampin was found to be 12.5 mg/L, which markedly inhibited non-Campylobacter strains while not affecting the survival of Campylobacter strains. After the Campylobacter spp. were enriched in Bolton broth supplemented with 12.5 mg/L rifampin (R-Bolton broth), CampyFood Agar (CFA) was found to be better in selectively isolating the pathogens in the enrichment broth than the International Organization for Standardization method of using modified charcoal cefoperazone deoxycholate agar (mCCDA) for this step. When applied to natural food samples-here, romaine lettuce, pepper, cherry tomato, Korean leek, and chicken-the R-Bolton broth-CFA combination decreased the number of false-positive results by 50.0, 4.2, 20.8, 50.0, and 94.4%, respectively, compared with the International Organization for Standardization method (Bolton broth-mCCDA combination). These results demonstrate that the combination of R-Bolton broth and CFA is more efficient in detecting C. jejuni and C. coli in poultry and fresh produce and thus should replace the Bolton broth-mCCDA combination.

In an attempt to develop a biological control agent against mycotoxigenic Fusarium species, we isolated Bacillus amyloliquefaciens strain DA12 from soil and explored its antimicrobial activities. DA12 was active against the growth of mycotoxigenic F. asiaticum, F. graminearum, F. proliferatum, and F. verticillioides both in vitro and in planta (maize). Further screening using dual culture extended the activity range of strain DA12 against other fungal pathogens including Botrytis cine rea, Colletotrichum coccodes, Endothia parasitica, Fu sarium oxysporum, Raffaelea quercus-mongolicae, and Rhizoctonia solani. The butanol extract of the culture filtrate of B. amyloliquefaciens DA12 highly inhibited the germination of F. graminearum macroconidia with inhibition rate 83% at a concentration of 31.3 μg/ml and 100% at a concentration of 250 μg/ml. The antifun gal metabolite from the butanol extract was identified as iturin A by thin layer chromatography-bioautogra -phy In addition, volatile organic compounds produced by DA12 were able to inhibit mycelial growth of vari ous phytopathogenic fungi. The volatile compounds were identified as 2-heptanone, 5-methyl heptanone and 6-methyl heptanone by gas chromatography-mass spectrometry (GC-MS) analysis. These results indicate that the antagonistic activity of Bacillus amyloliquefa ciens DA12 was attributable to iturin A and volatile heptanones, and the strain could be used as a biocontrol agent to reduce the development of Fusarium diseases and mycotoxin contamination of crops.

Rhodococcus fascians is a bacterium that causes growth abnormalities such as leafy galls, fasciation, and shoot proliferation in many plants, including ornamental plants. In February 2020, the Animal and Plant Quarantine Agency of South Korea detected 492,000 contaminated lily bulbs using an in-house PCR test based on the R. fascians fasD gene, and subsequently 1.3 million imported bulbs were destroyed. Because no pathogen isolation was associated with this diagnosis, there has been great cultivator demanded for bacterial isolation evidence of lily bulb infection with pathogenic R. fascians. To isolate the causal bacterium of the PCR tests, we sampled leaf, stem, and bulb tissues from 130 lilies with growth abnormality symptoms, collected from 24 South Korean mass production lily farms from June to August 2020. Supernatants of the homogenized samples were spread on mD2 medium (Kado and Heskett 1970) and incubated at 28°C for 10 days. Yellow to orange colonies were isolated into pure culture on mD2. Total DNA was extracted from cultures grown in yeast extract broth (YEB) at 28°C for 24 hours with Wizard DNA prep kit (Promega, Madison, WI, USA). PCR was performed to test for pathogenicity genes fas (A,D, and R) and att (A and R) (Putnam and Miller 2007). Colonies that produced at least one amplicon from these pathogenicity genes were analyzed by partial 16s rRNA gene sequencing to determine the corresponding species. Three strains that were isolated from the bulbs of fasciated lilies from Wanju (35°56´22.1˝N; 127°08´52.0˝E), Gwacheon (37°26´51.6˝N; 127°00´11.8˝E), and Yeongwol (37°18´45.8˝N; 128°11´05.6˝E), or W1, G3, and Y5 strains, yielded PCR products of the expected size for fas and att genes with the primer sets published in Serdani et al. (2013) and developed in this study (attAF: 5'-CCCGGCTACACGCATTCGC-3', attAR: 5'-CGAACGCGGTGTGCAGGT-3' and attRF: 5'-AGTGTCCCGTCGGCGAG-3', attRR: 5'-CGCGGCAGATCGAAGTCCT-3'). Sequences of the three strains were deposited in Genbank for fasA (accession MW122940-942), fasD (G3:MW122935 and 936), and fasR (MW122937-939); all shared 98.3 - 100% nucleotide identity to corresponding sequences from phytopathogenic R. fascians A25f (CP049745.1 Protein_ID fasA:QII09280.1, fasD:QII09282.1, and fasR:QII09277.1). The attA and attR products were only present in G3 (attA: MW122943 and attR: MW122944) and resulted in 100% identity to those of A25f (CP049745.1 Protein_ID attA:QII09269.1, attR:QII09267.1). Partial 16s rRNA gene sequences were obtained (MW064131-133) and clustered with phytopathogenic R. fascians strains D188, A21d2, and A25f. Thus we concluded that strains (W1, G3, and Y5) corresponded to R. fascians. To test the pathogenicity of these three strains, 10 seeds of garden peas for each strain were inoculated at 108 CFU/ml according to Nikolaeva et al. (2009), and the length of the main stem of each seedling was calculated 22 days post-inoculation. Seedlings inoculated with G3 and Y5 resulted in a stunted phenotype with up to 40% height reduction (p ≤ 0.001) compared to non-inoculated seedlings. As for the seedlings inoculated with W1, they exhibited as much as 15% height reduction (p ≤ 0.001). Colonies were recovered from the inoculated seedlings, identity was confirmed through colony PCR for fas and att genes. To our knowledge, this is the first report of phytopathogenic R. fascians in lilies cultivated in South Korea.

Fascioliasis, a food-borne trematode zoonosis, is a disease primarily in cattle and sheep and occasionally in humans. Water dropwort (Oenanthe javanica), an aquatic perennial herb, is a common second intermediate host of Fasciola, and the fresh stems and leaves are widely used as a seasoning in the Korean diet. However, no information regarding Fasciola species contamination in water dropwort is available. Here, we collected 500 samples of water dropwort in 3 areas in Korea during February and March 2015, and the water dropwort contamination of Fasciola species was monitored by DNA sequencing analysis of the Fasciola hepatica and Fasciola gigantica specific mitochondrial cytochrome c oxidase subunit 1 (cox1) and nuclear ribosomal internal transcribed spacer 2 (ITS-2). Among the 500 samples assessed, the presence of F. hepatica cox1 and 1TS-2 markers were detected in 2 samples, and F. hepatica contamination was confirmed by sequencing analysis. The nucleotide sequences of cox1 PCR products from the 2 F. hepatica-contaminated samples were 96.5% identical to the F. hepatica cox1 sequences in GenBank, whereas F. gigantica cox1 sequences were 46.8% similar with the sequence detected from the cox1 positive samples. However, F. gigantica cox1 and ITS-2 markers were not detected by PCR in the 500 samples of water dropwort. Collectively, in this survey of the water dropwort contamination with Fasciola species, very low prevalence of F. hepatica contamination was detected in the samples.

The purposes of this study were to develop a small scale post-harvest facility, and consequently to evaluate the effects of applying the facility along with hygiene education on the level of microbial safety in Korean leeks production. A total of 135 samples were collected at three Korean leeks farms in Yangju, Gyeonggi province. Food safety indicators (Aerobic plate count (APC), coliform count, and Escherichia coli) and foodborne pathogens (E. coli O157:H7, Salmonella spp., Staphylococcus aureus, Listeria monocytogenes, and Bacillus cereus) on/in the samples were assessed. The microbial load measured as APC with harvesting tools such as comb, chopping board, and knife, at the farms where the small scale post-harvest facility had been operated (Farms A and B) was lower than that at another farm having no post-harvest facility (Farm C) by 1.44~2.33 log CFU / 100 cm. Moreover, the chopping board from Farm C was observed being contaminated with B. cereus at 6.03 log CFU / 100 cm. The coliform counts from the samples increased by 0.57~1.89 log CFU/g after leeks was submerged in ground water for washing. E. coli was recovered from leeks, soil, and the ground water used in the washing process, while no E. coli O157:H7, Salmonella spp., and L. monocytogenes was detected. Our results indicated that the small scale post-harvest facility developed in this study as well as the hygiene education played an important role in enhancing the level of microbial food safety in the leeks production environment. However, a disinfection technique could be needed during the washing step in order to prevent a potential contamination.

Antagonistic microbes were isolated from soils to control mycotoxin contamination of cereals by limiting the growth of mycotoxigenic Fusarium species. In total, 341 bacterial isolates were examined for antifungal activity against eight mycotoxigenic Fusarium species using dual culture assays. The screening identified 11 isolates that inhibited mycelial growth of all Fusarium species tested. The culture filtrates of 2 of the 11 isolates completely inhibited germination of conidia up to 21 days of incubation. These two isolates exhibited identical activity toward the fungi tested and were identified as Brevibacillus spp. based on 16S rRNA sequence homology. The most closely related species based on phylogenetic analysis was Brevibacillus reuszeri. Additional dual culturing using further fungal species showed that the antagonistic Brevibacillus inhibited the growth of most Fusarium species tested (39 of 46 species), two Epicoccum spp., one Alternaria sp., three Aspergillus spp. (3 of 11), and three Penicillium spp. (3 of 8). The in vivo assay was performed to test the efficacy of antagonistic Brevibacillus isolates on maize ears and revealed that the application of microbes suppressed ear rot (ANOVA, p = 0.0020). This Brevibacillus sp. may be an antagonist of the majority of Fusarium species, including mycotoxigenic species.

To evaluate microbiological and aflatoxin safety on traditional dried persimmon, a total of 315 samples were collected from 105 farms. The collected samples were assessed on aflatoxin and microorganisms (Aer- obic plate count, coliform count, Escherichia coli, Escherichia coli O157:H7, Salmonella spp., Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus). The the APC of sliced dried persimmon, dried persimmon, and semi dried persimmon were 3.93 ± 0.96, 2.12 ± 0.93, and 1.50 ± 1.08 log CFU/g, respectively. S. aureus was detected in 40.0% of sliced dried persimmon, 29.5% of dried persimmon, and 23.5% of semi dried persimmon. E. coli recovered from dried persimmon and semi dried persimmon was 6.6%, and 2.9%, respectively. However, E. coli O157:H7, Sal- monella spp., and L. monocytogenes were not detected. According to the result of aflatoxin by ELISA and UPLC, aflatoxin was not detected in any sample. These data suggested that safety management system should be introduce to the farms producing traditional dried persimmon to enhance the safety of traditional dried persimmon.

This study was conducted to investigate survival of Bacillus cereus (B. cereus) on stainless steel and polyvinyl chloride (PVC) and its transfer from two material to lettuce. The stainless steel and PVC were innoculated with B. cereus and stored at 6 combination conditions (temperature : 20oC and 30oC, relative humidity (RH) : 43%, 69%, and 100%). Although the total numbers of B. cereus at RH 43% and RH 69% were reduced by 3.53-4.00 log CFU/coupon within 24 h regardless of material type, the spore numbers of B. cereus was lasted at 3.0 log CFU/ coupon. When two materials were stored at 30oC, RH 100%, the spore numbers of B. cereus was rapidly increased by 3.0 log CFU/coupon. In addition, the reduction rate of B. cereus was decreased in the presence of organic matter. Transfer rate of B. cereus from surface of stainless steel and PVC to lettuce was increased by 10 times in the presence of water on the lettuce surface. As a result of this study, the presence of B. cereus on produce contact surfaces can increase the risk of cross-contamination. Thus, it is important that the packing table and conveyer belt in post harvest facility should be properly washed and sanitized after working to prevent cross-contamination.

Foodborne illness due to the consumption of contaminated raw strawberries is a continuing food safety concern. This study investigated and evaluated contamination levels of bacteria on strawberries at farms stage to evaluate potential hazards associated with fresh strawberries. A total of 315 samples, 105 samples from 5 sampling sites (A to E) of 21 farms and 210 samples from 1 sampling site of 6 farms, was collected every month for four months and analyzed to enumerate aerobic bacterial counts, Coliforms/E. coli, Bacillus cereus and Staphylococcus aureus. In addition, the prevalence study of five pathogens (S. aureus, E. coli, E. coli O157:H7, Salmonella spp. and Listeria monocytogenes) was performed on each sample. Aerobic bacterial counts ranged from 0.48 to 6.36 Log CFU/g, with the highest bacterial cell counts recorded for D and E sites. Coliforms were detected in 71 samples (22.5%) with a minimum of 0.48 cfu/g and a maximum of more than 4 Log CFU/g. B. cereus was detected in 98 samples (31.1%) among total samples analyzed. S. aureus was detected in 2 samples with a minimum of 0.48 Log CFU/g and a maximum of 1.38 Log CFU/g. E. coli, E. coli O157:H7, Salmonella spp. and L. monocytogenes were not isolated from any of the samples. The microbial contamination levels of strawberries determined in this study may be used as the fundamental data for microbiological risk assessment.

This study assessed microbiological hazards at postharvest stage of dropwort farms (A, B, C, D, E, F, G, H, I) located in 4 different areas in Korea. The samples were assessed for sanitary indication bacteria (total aerobic bacteria, coliform, and Escherichia coli) and pathogenic bacteria (Escherichia coli O157:H7, Listeria monocytogenes, Staphylococcus aureus and Bacillus cereus). Total aerobic bacteria and coliform in 9 dropwort farms were detected at the levels of 0~7.00 and 0~4.25 log CFU/g, mL, of 100 cm. In particular, microbial contamination in worker’s hand showed higher than cultivation environment factors. Escherichia coli was detected in several farms of soil, irrigation water, washing water and worker’s hand and also, dropwort in these farms was contaminated with E. coli (positive reaction). In case of pathogenic bacteria, B. cereus was detected at the highest levels in soil. S. aureus was detected qualitatively from only one sample of dropwort washed by water. E. coli O157:H7 and L. monocytogenes were not detected. Although dropwort pass through 2 process (trimming and washing), the microbial contamination was not differ significantly before and after which indicates that current washing system was not effect on reduction of microorganism. From these results, the postharvest environment and workers have been considered as cross-contamination factors. Thus, processing equipments and personal hygiene should be managed to reduce the microbial contamination of dropwort. Accordingly management system such as good agricultural practices (GAP) criteria is needed for the safety of dropwort

This study investigated the effect of adaptation of Staphylococcus aureus strains to the acidic condition of tomato in response to environmental stresses, such as heat and acid. S. aureus ATCC 13565, ATCC 14458, ATCC 23235, ATCC 27664, and NCCP10826 habituated in tomato extract at 35°C for 24 h were inoculated in tryptic soy broth. The culture suspensions were then subjected to heat challenge or acid challenge at 60°C and pH 3.0, respectively, for 60 min. In addition, transcriptional analysis using quantitative real-time PCR was performed to evaluate the expression level of acid-shock genes, such as clpB, zwf, nuoF, and gnd, from five S. aureus strains after the acid habituation of strains in tomato at 35°C for 15 min and 60 min in comparison with that of the nonhabituated strains. In comparison with the nonhabituated strains, the five tomato-habituated S. aureus strains did not show cross protection to heat, but tomato-habituated S. aureus ATCC 23235 showed acid resistance. In quantitative real-time-PCR analysis, the relative expression levels of acid-shock genes (clpB, zwf, nuoF, and gnd) were increased the most in S. aureus ATCC 23235 after 60 min of tomato habituation, but there was little difference in the expression levels among the five S. aureus strains after 15 min of tomato habituation. These results indicate that the variation of acid resistance of S. aureus is related to the expression of acid-shock genes during acid habituation.

The objective of this study was to analyze the microbiological hazards of Astragalus membranaceus Bunge on the post-harvest processing. Samples from processing equipments (cleaner, water, cart, table, tray and pack- aging machine), personal hygiene (hand) and harvested crops (before washing, after washing, after sorting, and after drying) were collected from four farms (A, B, C, and D) located in Chungchengbuk-do, Korea. The samples were analyzed for sanitary indication bacteria and pathogenic bacteria. First, total aerobic bacteria and coliform in process- ing facilities were detected at the levels of 0.93~4.86 and 0.33~2.28 log CFU/100 cm 2 and /mL respectively. In partic- ular, microbial contamination in hand (5.43~6.11 and 2.52~4.12 log CFU/Hand) showed higher than processing equipments. Among the pathogenic bacteria, Bacillus cereus was detected at the levels of 0.33~2.41 log CFU/100 cm 2 , 1.48~3.27 log CFU/Hand and 0.67~3.65 log CFU/g in equipments, hands, and plants and Staphylococcus aureus were detected in cleaner, table, hand and harvested crops (before washing and after sorting) by qualitative test. Escher- ichia coli O157:H7, Listeria monocytogenes, and Salmonella spp. were not detected. These results indicated that per- sonal hygiene and processing equipments should be managed to reduce the microbial contamination of A. membranaceus Bunge. Therefore, management system such as good agricultural practices (GAP) criteria is needed for hygienic agricultural products.

This study investigated and evaluated contamination levels of bacteria on tomatoes at farms stage to evaluate potential hazards associated with fresh tomatoes. A total of 170 samples, 90 samples from 5 sampling sites from 18 farms and 80 samples from 1 sampling site from 4 farms every month for four months, were analyzed to enu- merate aerobic bacterial counts, coliforms, E. coli, Bacillus cereus, Staphylococcus aureus, Escherichia coli, E. coli O157:H7, Salmonella spp., and Listeria monocytogenes. Aerobic bacterial counts ranged from 0.48 to 6.15 Log CFU/ g, with the lowest and the highest bacterial cell counts recorded for A site and E site, respectively. Thirty five percent of the samples from the E site contained more than 2 Log CFU/g. Six samples (6.6%) of 90 samples contained B. cereus less than 1 Log CFU/g. In addition, the contamination level of indicator bacteria and B. cereus in tomatoes were higher on March than on April, May and June (P < 0.05). S. aureus, E. coli, E. coli O157:H7, Salmonella spp. and L. monocytogenes were not detected in the tomato samples. The microbial contamination levels of tomatoes deter- mined in this study may be used as the data for microbiological risk assessment.

This study was performed to investigate the biological characteristics of the brown lacewing Micromus angulatus (Stephens)at four different temperatures (15, 20, 25, and 30 ℃) and 70 ± 10% relative humidity under a photoperiodic regime of 16: 8(L:D) h. Thedevelopmental threshold and effective accumulative temperature from egg to pupa for M. angulatus were 9.6 ℃ and 270.3 day-degrees,respectively. The developmental period of egg, larva, and pupa at 25 ℃ was 4.4, 5.5, and 6.9 days. respectively. The longevity of an adul tfemale M. angulatus was 34.9 days. The oviposition period for M. angulatus was 28.7 days, in which it laid a total number of 515.2 eggsduring its life span. The maximum number of eggs laid by a female in a day was 54.8. Daily consumption by M. angulatus at 25℃was18.9 1 st instars, 47.2 2 nd instars, 57.7 3 rd instars, and 91.0 adults of the glasshouse potato aphid, Aulacorthum solani . Therefore, M. angulatu scould be a promising biological control agent against aphids. Key words: Natural enemy, Micromus angulatus, Development, Oviposition, Predation초 록: 본 연구는 온도(15, 20, 25, 30℃), 습도(70 ± 10%), 광주기(16L:8D)에서 갈고리뱀잠자리붙이의 생물적 특성을 조사하기 위해 수행되었다. 알에서부터 번데기까지의 발육영점온도 및 유효적산온도는 각각 9.6℃ 및 270.3일도였다. 25℃에서 갈고리뱀잠자리붙이의 알 기간은 4.4일, 유충은 5.5일, 번데기는 6.9일이었다. 암컷 성충의 수명은 34.9일, 산란 기간은 28.7일이었고, 총 산란수는 515.2개, 1일 최대 산란수는 54.8개였다. 25℃에서 갈고리뱀잠자리붙이에 의한 싸리수염진딧물의 1령, 2령, 3령 및 성충의 일일 포식량은 각각 18.9, 47.2, 57.7 및 91.0마리이었다. 따라서 갈고리뱀잠자리붙이는 진딧물의 포식성 천적으로 이용이 가능할 것으로 여겨진다 .검색어: 천적, 갈고리뱀잠자리붙이, 발육, 산란, 포식*Corresponding author: kim9@korea.krReceived April 12 2013; Revised August 12 2013Accepted August 27 2013진딧물은 전 세계적으로 약 4천여 종이 분포하는 것으로 알려져 있다(Blackman and Eastop, 1984). 농작물에 발생하는 진딧물은 식물의 양분을 빨아먹고 질병을 매개할 뿐만 아니라 번식력과 발육속도가 빨라 많은 피해를 주는 매우 중요한 해충이다. 진딧물의 방제는 주로 화학농약을 이용하여 왔으나 , 농산물의 생산자와 소비자 모두 인체에 해롭다는 인식에는 공감하고 있다. 2000년대부터 농약사용을 줄일 수 있는 해충방제 인자로 천적을 이용한 방제법이 본격화되었으며 , 현재 진딧물의 생물적 방제용으로 판매되고 있는 천적은 8종정도이다(http://www. dongbufarmceres.co.kr/).진딧물의 포식성 천적으로 알려진 갈고리뱀잠자리붙이(Micromus angulatus)는 풀잠자리목(Neuroptera) 뱀잠자리붙이과(Hemerobiidae)에 속하는데, 진딧물 뿐 만 아니라 깍지벌레나 응애류 등도 포식하는 광식성이다 (New, 1975; Samson and Blood, 1980; Navi et al., 2010; MacLeod and Stange, 2011). 본 종은 주로 열대와 온대지역에 분포하며 (Navi et al., 2010), 우리

This study was conducted to develop temperature-dependent postdiapause development models of overwintering larvae of the Asian corn borer, Ostrinia furnacalis Guenee (Lepidoptera: Crambidae), and to evaluate the models' forecasting accuracy using spring adult emergence data. Overwintering larvae were collected at three different times: 24 February (first), 23 March (second), and 25 April (third), 2005. The developmental periods of each collection colony were measured at eight constant temperatures, and those developmental rates were modeled with linear and nonlinear regression. One linear and three nonlinear models provided good fits of developmental rate to temperature across all colonies (r2 = 0.96-0.99). The distribution of development completion time was modeled with a Weibull equation that fit data from the second (r2 = 0.92) and third (r2 = 0.97) colonies better than the first (r2 = 0.87). A Lactin 2 model based on data from the first colony was statistically the best model to describe the relationship between temperature and the postdiapause development rate of O. furnacalis (r2adj = 0.99). However, validation results based on the field data showed that the Logan 6 model combined with the Weibull model (based on the second colony) was well describing spring adult emergence patterns up to 50% cumulative emergence date.

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), respectively, were compared with those developed in reciprocal eggs at constant temperatures of 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() and highest in HAr-HAs(), 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( wasps), and the lowest was CC-HAs( wasps).

This study reports the results of natural enemy application against four insect pests on greenhouse sweet pepper in winter cropping system. Orius laevigatus () was released at two different times (Nov. 2005 & Feb. 2006) to control Frankliniella occidentalis, western flower thrips (WFT). Throughout the cropping season, the lowest level recorded of WFT was less than 2.0 individuals per yellow sticky trap. Amblyseius swirskii () was released four times (Nov. 2007 ~ Aug. 2008) to control Bemisia tabaci, tobacco whitefly (TWF). Until July 2008, TWF population had been suppressed lower than 6.6/trap. Phytoseiulus persimilis () was released seven times (Apr. 2008 ~ Aug. 2008) to control Tetranychus kanzawai, tea red spider mite (TRSM). As a result, TRSM population was suppressed lower than 1.7/1eaf. To control aphids, Aphidius colemani () was released seven times (Oct. 2004 ~ Jan. 2005), with the transplantation of banker plants (). As a whole, aphid`s population has been successfully reduced to less than 2.0/leaf.

Development of immature Thrips palmi Karny was investigated at 12.5, 15, 17.5, 20, 22.5, 25, 27.5, 30, 32.5, and 35℃, 20?40% RH and a photoperiod of 14:10 (L:D) h. Developmental time decreased with increasing temperature up to 32.5℃ in all stages. The total developmental time was longest at 12.5℃ (64.2 days) and shortest at 32.5℃ (9.2 days). The lower developmental threshold was 10.6, 10.6, 9.1, and 10.7℃ for egg, larva, prepupa, and pupa, respectively. The thermal constant required to complete the respective stage was 71.7, 59.2, 18.1, and 36.8DD. The lower threshold temperature and thermal constant were 10.6℃ and 183.3DD, respectively, for total immature development. The nonlinear relationship between developmental rate and temperature was well described by the modified Sharpe and DeMichele biophysical model (r 2 =0.905?0.998). The distribution of developmental completion of each stage was described by the 3-parameter Weibull function (r 2 =0.855?0.927). The temperature-dependent developmental models of T. palmi developed in this study could be used to predict its seasonal phenology in field and greenhouse vegetable crops.

Trichogramma wasps parasitize eggs of various insect species. Several Trichogramma species have been commercialized to manage Lepidopteran agricultural pests. Correct species identification is essential for successful biological control. However, the microscopic size and morphological similarity of Trichogramma species makes correct identification very difficult. Internal transcribed spacer (ITS)-2 gene sequences have been used to identify Trichogramma species. Using this molecular marker, Trichogramma species that are commercially available in Korea were identified as Trichogramma ostriniae and Trichogramma brassicae. The latter has not previously been reported in Korea. Additionally, Cadra cautella and Sitotroga cereallela eggs (host eggs of the commercialized Trichogramma species in Korea) were infected with Wolbachia. However, Trichogramma were not infected with the bacterium. This indicates that horizontal transfer of Wolbachia does not occur from host to wasp.

Biological-control-based-integrated-pest-management of major pests occurring on sweet pepper in greenhouse during summer season was tried. As many as 2.1 Orius laevigatus per were released in two times on June 6 and 19, and the population of thrips was kept under control and accordingly the damage was negligible throughout the season. To control aphids, a total of 0.8 Aphidius colemani per were released in four times, 0.2 of them at a time, flonicamid on May 14 and July 18 and pymetrozine on June 14 and September 4 were sprayed on the spots of high aphid occurrence to reduce the release of the wasp, and the density of aphids was kept under control. Whitefly was controlled successfully by releasing a total of 343.4 Amblyseius swirski per in nine times, 38.1 of them at a time, from May 9 until November 12 and dinotefuran was sprayed on November 12 when the density of whitefly increased up to 200 per trap. Tetranichus kanzawai was controlled by both Phytoseiulus persimilis which was released a total of 44.4 per in five times 8.9 of them at a time from May 23 to September 10, and the A. swirski which was released for the control of whitefly.

By releasing predatory mite, Amblyseius swirskii Athias-Henriot, with 25 individuals per cucumber plant in a commercial greenhouse (1,600 ), the population of western flower thrips, Frankliniella occidentalis (Pergande), was kept under the economic threshold level. The initial thrips population of 18.3 individuals per leaf decreased to 2.1 individuals per leaf after four weeks, while the number of A. swirskii reached to 16.6 individuals per leaf. It was also observed that at a point where the thrips occurred in high density of about 34.3 individuals per leaf, A. swirskii population built up on the lower part of cucumber plant first, but as time passed the predatory mites moved upward to the top of the plant and aggregated.

We have investigated some biological characteristics, such as survival rate and fecundity, of Orius laevigatus and Phytoseiulus persimilis, which have been stored at 6, 8, 10, , RH , in dark condition. Overall, an appropriate temperature for cold storage was for O. laevigatus and for P. persimilis. 70% of adult O. laevigatus could survive for 36 days at . The O. laevigatus stored at for days laid eggs. Since fresh (no storage) O. laevigatus laid 224.5 eggs, comparative fecundity of stored adults was of normal fecundity. P. persimilis stored at for days with (food eggs of Tetranychus urticae) laid eggs. Since fresh P. persimilis laid 26.4 eggs, comparative fecundity of stored adults was of normal fecundity.

Without pesticide applications, mass-trapping by sex pheromone was successful to control Spodoptera litura (Fabricius) in a large scale tomato glasshouse (10,000 ) at a low cost of 60 won/. Pheromone traps were placed both inside and outside of the glasshouse. Inside the glasshouse traps were installed in a regular space, one trap per 500 , to catch the moths that were present in the glasshouse, and traps were also set outside of the glasshouse, at intervals of ca. 20 m, to prevent the moths from invading the glasshouse. In the experiment, more than 400 S. litura were captured per trap.

On the leaf disc of fruit vegetables (cucumber, sweet pepper, tomato, egg plant, oriental melon), it has been evaluated that the capability of four predatory mites ( Amblyseius swirskii Athias-Henriot, Neoseiulus barkeri (Hughes), N. cucumeris (Oudemans), N. californicus (McGregor)) to prey on the eggs of Bemisia tabaci (Gennadius) and to lay own eggs. The most aggressive mite was A. swirskii which had consumed about 9~12 eggs in a day. The quantity of eggs consumed by N. barkeri , N. cucumeris and N. californicus was about 6~9, 4~6 and 1~4, respectively. The most productive mite was also A. swirskii which had laid about 1.2~1.9 eggs in a day. The others could not lay more than 0.5 eggs in a day. KEY WORDS : Bemisia tabaci , Amblyseius swirskii , Neoseiulus barkeri , Neoseiulus cucumeris , Neoseiulus californicus 초록 : 시설과채류(오이, 착색단고추, 토마토, 가지, 참외)의 잎 절편에서 지중해이리응애 , 나팔이리응애, 오이이리응애, 사막이리응애를 대상으로 담배가루이 알에 대한 포식능력과 산란능력을 비교 평가하였다 . 지중해이리응애의 일평균 담배가루이 알 포식량이 9~12개로 가장 많았으며, 나팔이리응애, 오이이리응애, 사막이리응애가 각각 6~9개, 4~6개, 1~4개로 뒤를 이었다. 일평균 산란수도 지중해이리응애가 1.2~1.9개로 가장 많았으며, 다른 포식응애들은 0.5개를 넘지 않았다.검색어 : 담배가루이, 지중해이리응애, 나팔이리응애, 오이이리응애, 사막이리응애최근 담배가루이 Q계통이 국내에 유입되어 시설과채류를 중심으로 큰 피해를 주고 있다 (Lee

With the comparison of native Orius strigicollis (Poppius) to European O. laevigatus (Fieber), we investigated biological characteristics such as developmental period, fecundity, life span, predation ability, and augmentation after release. Experiments were carried out at five temperature condition, , and . In the case of O. strigicollis, egg period was days (hatchability: ), and developmental period of nymphs was days (survival rate: ). Fecundity at each temperature was 28.1, 107.9, 123.6, 127.3, and 18.1, respectively. Life span of adults was 63.4, 40.1, 22.1, 18.3, and 11.0 days, respectively. In the case of O. laevigatus, egg period was days (hatchability: ), and developmental period of nymphs was (survival rate: ) days. Fecundity at each temperature was 101.8, 218.6, 224.5, 219.5, and 15.7. Life span of adults was 70.6, 66.4, 32.6, 34.5, and 7.3 days, respectively. In long-day condition (16L:8D), fecundity of O. strigicollis and O. laevigatus was 105.8 and 109.5 , respectively. In short-day condition (10L:14D), fecundity of them was 1.0 and 63.0 , respectively. Daily prey consumption of second instar Frankliniella occidentalis was 14.3 and 10.9, respectively. In greenhouse, density of O. strigicollis begins to increase from mid May and peaked about early July (1.8 individual/flower), while that of O. laevigatus begins to increase from mid March and peaked about early June (6.6 individual/flower).

Populations of cotton aphid on Hibiscus syriacus increased rapidly from 17 to 24 May 2007, and then decreased as its predator, the lady beetle Hamonia axyridis, increased in number. There was a 10 day time lag between peak populations of aphids and lady beetles. The infestation of aphids on H. syriacus produced some damage, but H. syriacus recovered soon after the lady beetles arrived. Cotton aphid clones from H. syriacus were transferred to other summer host plants: to five different vegetables on two dates, and to cucumber on three dates. Apart from one case where reproduction occurred on eggplant, most H. syriacus aphid clones did not survive on the vegetables. The cotton aphid on H. syriancus was prey and a food source for H. axyridis and acted to conserve natural enemies.

Accurate forecasting of pest density is essential for effective pest management. In this study, a simple image processing system that automatically estimated the density of whiteflies on sticky traps was developed. The estimated densities of samples in a laboratory and a greenhouse were in accordance with the actual values. The detection system was especially efficient when the whitefly densities were at medium to high levels, however, the development of identification algorithms and more appropriate collection methods may improve the image processing system. Taken together, the results of this study indicate that the image processing system described here may be useful for evaluating the population dynamics.

We investigated the effect of shear forces perpendicular to the interface on the interfacial morphology of a reactive bilayer. It was observed that the perpendicular shear force greatly enhanced the roughness of the interface compared with parallel shear force. The main role of in situ formed graft copolymers is not to increase greatly the roughness of the interface, but to stabilize the interfacial morphology. We also observed that microemuslsions were observed at both the PMMA and PS layers, which is distinctly different from the situation obtained under parallel shear force (or without shear) that the microemlusions were seen in only the PMMA layer.

[Purpose] The present study investigated a wide range of stroke patients living in South Korea using the Korean Community Health Survey raw data to determine the correlation between stroke and physical activity. [Subjects and Methods] This study used raw data from the 2012 Korean Community Health Survey. The total number of participants was 228,921; of the 4,475 stroke patients who had been diagnosed by a medical doctor or an oriental medical doctor, the data for 4,460 patients, excluding 15 whose amount of physical activity was unclear, were used in the analysis. [Results] The amount of physical activity performed by patients who had sequelae was significantly lower than that performed by patients who no longer had sequelae. Similarly, for the type of sequelae, palsy in the arms and legs, facial palsy, communication disability, swallowing or eating disability, and visual disability were associated with lower physical activity. Furthermore, as the number of sequelae increased, patients performed significantly less physical activity. [Conclusion] The findings suggest that when decisions on national policies and budgets are made, methods for increasing the physical activity of patients with a history of stroke should be considered.

Biological control of Liriomyza trifolii (Burgess) using Diglyphus isaea (Walker) has been evaluated in tomato greenhouse, for three seasonal culture types: spring type (March-July), summer type (June-October) and autumn type (July-December). For spring type, totally 5.8 of D. isaea has been released at six times from late April, when the density of L. trifolii was about 1.0 individuals/plant. Corrected mortality of Liriomyza trifolii caused by parasitoids was 97.6% at early July, and the proportion of D. isaea was 88.9% of all parasitoids collected in the greenhouse. In the case of summer type, totally 1.8 of D. isaea has been released at five times from early July, when the density of 1. trifolii was about 0.4 individuals/plant. Corrected mortality of L. trifolii caused by parasitoids was 84.4% during the whole season, but the proportion of D. isaea was very low (only 13.8%). Immigrating parasitoids such as Chrysocharis penthus were synchronized to control the leafminer in the greenhouse. For autumn type, totally 2.7 of D. isaea has been released at four times from mid September, when the density of L. trifolii was about 0.7 individuals/plant. Corrected mortality of f. trifolii caused by parasitoids was 85.7% at mid December, and the proportion of the D. isaea was 83.4%.

Experiments have been performed to investigate biological characteristics of Diglyphus isaea (Walker), an ectoparasite of Liriomyza trifolii (Burgess). At , development time of D. isaea was estimated as 1.3 days for eggs, 4.5 days for larvae and 6.3 days for pupae. Adult longevity was 25.1 days, and a female adult could lay 305.3 eggs throughout its lifetime. Number of L. trifolii parasitized or killed by the wasp was 962.2 individuals/adult. Most of all parasitized or killed larvae were identified as third instar. With 20% honeyed water as food source, half of the adults could survive 180 days at , 150 days at , and 90 days at . After storing at with absolute honey for 30 days, 70 days and 140 days, a female adult in room temperature laid eggs 190.8 individuals, 104.0 individuals and 89.4 individuals, respectively.

Effect of Interfacial Reaction and Morphology on Rheological Properties of Reactive Bilayer

We investigated, via atomic force microscopy and transmission electron microscopy, the effect of oscillatory shearing amplitude ( γ 0 ) and frequency ( ω ) on the interfacial morphology of a reactive bilayer polymer system composed of end-functionalized polystyrene with carboxylic acid (PS-mCOOH) and poly(methyl methacrylate- ran -glycidylmethacrylate) (PMMA–GMA). It has been observed that in the absence of oscillatory shearing (or at very small values of γ 0 and ω ), the roughness of the interface increased with reaction period, while at large values of γ 0 and ω it became less than that observed in the absence of oscillatory shearing. This observation may be attributable to the possibility that oscillatory shearing might have hindered the diffusion of polymer chains, which are located away from the interface, to the interface of the layers. However, the effect of γ 0 and ω on the roughness of the interface of (PS-mCOOH)/(PMMA–GMA) bilayer is found to be quite different. Specifically, when a large γ 0 was first applied to the bilayer, followed by application of a low γ 0 , the reactive polymer chains diffused into the interface of the (PS-mCOOH)/(PMMA–GMA) bilayer; and then the roughness of the interface increased. However, when a high ω of oscillatory shear flow was first applied to a specimen, followed by application of a low ω of oscillatory shear flow to the same specimen, a relatively low degree of roughness of the interface was observed. This is attributable to the fact that the oscillatory shear with a large ω generated a multilayer microstructure consisting of PS and PMMA layers, which apparently played the role of an obstacle (or diffusion barrier) that hindered the diffusion of both reactive polymer chains to the interface for chemical reactions.

A trigonometric approximation was used to describe the head shape of common vegetable-feeding aphids, Aphis gossypii Glover, Aulacorthum solani (Kaltenbach), Brevicoryne brassicae (Linne), Macrosiphum euphorbiae (Thomas), and Myzus per-sicae (Sulzer). After acquiring and standardizing digital images of the alate aphids, a frontal curve was represented as a set of points in a given domain, -π/2 ≤ x ≤ π/2. Then, the points were approximated by the function, y = a 0 + ∑ n = 1 45 ( a 2 n − 1 cos ( 2 n − 1 ) x + a 2 n sin 2 n x ) π Coefficients of the function were calculated by multiple regression analysis, and the averages of coefficients were used to reconstruct the generalized shape of each species.

The effect of chain architecture of in situ formed copolymers on the interfacial morphology of reactive polymer blends was investigated. We found that the chain architectures of copolymers at the interface significantly affected the reaction and interface roughness. Although the amount of in situ formed Y-shaped graft copolymers was smaller than that for diblock copolymers, the interface area generated by the former was larger than that generated by the latter.

An electric field was applied to reactive bilayer thin films consisting of poly(methyl methacrylate-ran-glycidyl methacrylate) (PMMA−GMA) and polystyrene (PS) with various amounts of monocarboxylic acid end-functionalized PS (PS-mCOOH). The fast growing wavelength (λmax) of the interfacial fluctuation under an electric field decreased sharply and approached a steady value with increasing amounts of PS-mCOOH. This is because of the decrease in interfacial tension (γ) between PMMA−GMA and PS resulting from the formation of PMMA-g-PS copolymers in-situ from the reaction between two functional groups of GMA and mCOOH. The reduction of γ with increasing amount of PS-mCOOH was verified from a reduction in the dispersed domain size. For a reactive bilayer where Y-shaped graft copolymers were formed, the pillars with flattened top surface were observed even when they did not touch the upper electrode. This result is in contrast to that seen for nonreactive bilayer or even other reactive bilayer where diblock copo...

The effect of organoclay platelets on morphologies of three blend compositions (80/20, 20/80, and 99.5/0.5 w/w) of nylon-6 (N6) and poly(ethylene-ran-propylene) rubber (EPR) has been studied by scanning and transmission electron micrographs. For the 80/20 (w/w) N6/ERP blend, the dispersed domain size (D) of EPR phase in the N6 matrix decreased significantly even if a small amount of the organoclay was added. The extent of the decrease in D in this blend was similar to N6/EPR blend with an in-situ reactive compatibilizer of EPR-g-maleic anhydride. The D of the blend with the clay did not change upon further annealing at high temperatures, which suggests that the clay seems to be an effective compatibilizer. But, for the 20/80 (w/w) N6/EPR blend, dispersed N6 domain did not decrease with increasing the amount of the clay up to 2 wt %. Moreover, the dispersed N6 domains were not stable against further annealing at high temperatures; thus, coalescence of N6 domains was observed. Furthermore, for 99.5/0.5 (w/w...

The temporal change of complex viscosity (η*) of two plates consisting of an end-functional monocarboxylated polystyrene (PS−mCOOH) and poly(methyl methacrylates) (PMMA) with various amounts of pol...

Fasciola hepatica is a trematode that causes zoonosis mainly in cattle and sheep and occasionally in humans. Fascioliasis has been reported in Korea; however, determining F. hepatica infection in snails has not been done recently. Thus, using PCR, we evaluated the prevalence of F. hepatica infection in snails at 4 large water-dropwort fields. Among 349 examined snails, F. hepatica-specific internal transcribed space 1 (ITS-1) and/or ITS-2 markers were detected in 12 snails and confirmed using sequence analysis. Morphologically, 213 of 349 collected snails were dextral shelled, which is the same aperture as the lymnaeid snail, the vectorial host for F. hepatica. Among the 12 F. hepatica-infected snails, 6 were known first intermediate hosts in Korea (Lymnaea viridis and L. ollula) and the remaining 6 (Lymnaea sp.) were potentially a new first intermediate host in Korea. It has been shown that the overall prevalence of the snails contaminated with F. hepatica in water-dropwort fields was 3.4%; however, the prevalence varied among the fields. This is the first study to estimate the prevalence of F. hepatica infection using the vectorial capacity of the snails in Korea.