Bemisia tabaci, sweetpotato whitefly, has been recognized one of the most destructive insect pests worldwide because of increased resistance to some insecticide groups requiring alternative strategies for its control. We conducted a study of the influence of relative humidity, temperature and different developmental stages on the susceptibility of sweetpotato whitefly to conidia of Isaria javanica isolate, which had been reported high virulence against Q biotype of B. tabaci. The mortality of tobacco whitefly was low at low constant relative humidities, but was high when kept high humidity for first 24 hours and transferred to low humidity. The Isaria isolate had wide range of temperature (15℃ to 35℃) to control sweetpotato whitefly. The isolate has virulence to the egg and all developmental stages of nymph of B. tabaci. These results indicated that the isolate had good control effects at various environmental conditions and is an excellent candidate to develop a microbial pesticide to control sweetpotato whitefly.

Bacillus thuringiensis (Bt) is a gram-positive bacterium that produces parasporal crystal proteins known as endotoxins or Cry proteins. The Cry protoxins are then cleaved by insect midgut proteinases to form active Bt toxins. The activated Cry protein then binds to specific receptors at the midgut epithelium. Cadherin-like and aminopeptidase N (APN) proteins are involved in Bt toxin binding by interacting sequentially with different toxin structures. Aminopeptidase N (APNs) from several insect species have been shown to be putative receptors for these toxins. We have characterized four different midgut APNs(APN1, APN2, APN3, APN4) cDNAs from S. exigua. Forward primers and reverse primers for confirmation of four different midgut APNs were designed based on their sequences cloned from the cDNA libraries. Quantitative RT-PCR procedures includes 42℃ for 20min (cDNA synthesis), 99℃ for 5min, and 35 cycles (94℃ for 1min, and 60℃ for 50 s) for collection. Four aminopeptidase N isoforms were confirmed with qRT-PCR. Sequence analysis was performed by BlastX search the National Center for Biotechnology Information(NCBI) nucleotide. Furthermore, double-stranded RNAs(dsRNAs) were synthesized. DsRNAs were determined for bioassay.

Antibiotic resistant salmonellosis has shown a recent increase, making treatment of patients with Salmonella infections difficult. This study analyzed changes in the species, serogroups, and antimicrobial susceptibility of enteric pathogens isolated from stool specimens during a period of eight years from 2003 to 2010 in a tertiary hospital. In total, 237 pathogens (1.9%) were isolated from 12,289 stool specimens, comprising 50.6% NTS and 49% Vibrio parahaemolyticus. Serogroups D, B, and C Salmonella were isolated most frequently, in that order. Of the Salmonella, 49% of the isolates were ampicillin resistant and this rate for serogroups B, C, and D Salmonella was 56.8, 64.7, and 43.5%, respectively. Overall, the rates of trimethoprim-sulfamethoxazole (SXT), chloramphenicol (CM), and ciprofloxacin resistance were 11.0, 22.0, and 0%, respectively. Two cefotaxime-resistant Salmonella were isolated in 2010. All of the V. parahaemolyticus were susceptible to SXT, CM, and tetracycline. In conclusion, NTS and V. parahaemolyticus were the major enteric pathogens isolated from stool during the eight years examined, and the rate of Salmonella resistance to antimicrobial agents showed a significant increase. Antimicrobial susceptibility testing is mandatory for proper treatment of patients with Salmonella spp. infection.

해충저항성 Bacillus thuringiensis (Bt) 벼의 비표적곤충인 벼물바구미(Lissorhoptrus oryzophilus)에 대한 성충 전용살충제 Clothianidin 액상수화제의 살충제 감수성 시험을 실시한 결과, 72시간-LC50은 0.245 ml/L(95% 신뢰한계는 0.195~0.307 ml/L)이었으며, Bt벼의 모본으로 대조로 사용한 낙동벼의 72시간-LC50은 0.257 ml/L(95% 신뢰한계는 0.199~0.331 ml/L)이었다. 72시간-LC50은 낙동벼에서 다소 높았지만, 해충저항성 Bt벼 72시간-LC50이 낙동벼의 95% 신뢰한계 내에 포함되어, 두 품종의 LC50값에 유의성이 없는 것으로 판단된다.

Oral viridans streptococci are recognized as one of the etiological agents of a variety of infectious diseases such as dental caries and infective endocarditis. Although antimicrobial susceptibility tests for these fastidious bacterial species are now established and standardized, a comparison between the broth microdilution and broth macrodilution tests has not previously been performed. This comparison was performed in the present study using the tests adopted by the Clinical and Laboratory Standards Institute (CLSI) and seven clinical isolates of oral viridans streptococcal strains. A modified broth macrodilution susceptibility test method was also included in this analysis, in which the media was not supplemented with horse blood. The susceptibility interpretation category agreements were measured at 83% (broth microdilution versus broth macrodilution) and 71% (broth microdilution versus modified broth macrodilution). The interpretation category agreement between the broth macrodilution and modified broth macrodilution tests was also 83%. These data indicate that the interpretation of antibiotic susceptibility test results for oral viridans streptococci are influenced by the methods used.

Recently, the Q biotype of tobacco whitefly has been recognized as the most hazardous strain of worldwide because of increased resistance to some insecticide groups requiring alternative strategies for its control. We studied the susceptibility of this biotype of B. tabaci to 21 isolates of Beauveria bassiana, 3 isolates of Isaria spp., 1 isolate of P. cateni，3 isolates of Lecanicillium lecanii, 1 isolate of L. attenuatum and 1 isolate of Aschersonia aleyrodes. These isolates were evaluated on pruned egg plant seedlings, at a concentration of 108conidia/ml (deposited at 6000±586 conidia mm-2). The mortality based on mycosis varied from 18 to 97% after 6 days. An Isaria sp. isolate, two B. bassiana isolates and a L. lecanii isolate were found the most effective. Furthermore, five isolates were chosen for concentration-mortality response assays and compared to B. bassiana GHA as a standard. The numbers of nymphs infected by fungi were correlated with the spore concentration. A L. lecanii isolate and Isaria sp. had the short LT50 at 6000±586 conidia mm-2. Mortality reduced and LT50s were longer as the concentration of conidia was reduced. The LD50 values were differed in isolates from 87 to 269 conidia mm-2. These results indicated that the Q biotype of sweetpotato whitefly was susceptible to the five isolates of entomopathogenic fungi and these isolates have potential to be developed as a microbial pesticide for whitefly control.

The antimicrobial susceptibility of the 41 Bordetella bronchiseptica isolates was tested by using the Kirby-Bauer agar disk diffusion method. The B. bronchiseptica isolates were found to be sensitive to amoxicillin/clavulanic acid (100%), gentamicin (100%), neomycin (100%) and amikacin (97.6%), whereas they were resistant to streptomycin (100%), trimethoprim/sulfamethoxazole (100%), penicillin (100%) and ampicillin (97.6%). All the B. bronchiseptica isolates resisted to at least 4 antimicrobial agents and totally 8 different combinations of multiple antibiotic resistance patterns were noted. All of the B. bronchiseptica isolates, except one, were simultaneously resistant to streptomycin, trimethoprim/sulfamethoxazole, penicillin and ampicillin. The observed antibiotic resistance is not plasmid mediated as plasmids were absent from all the B. bronchiseptica isolates.

Field-collected populations of mayflies, Ephemera orientalis were tested for susceptibility to 10 different insecticides using a direct-contact mortality bioassay. Ephemera orientalis subimagoes were susceptible to the insecticides chlorpyrifos, fenitrothion and chlorfenapyr with LD50 values of 69.7, 78.8 and 81.9μg/♀, and adults had LD50 values of 71.9, 78.8 and 85.4μg/♀, respectively. Susceptibility ratios(SRs) of subimagoes and adults of E. orientalis to the 10 insecticides were 1.0 to1.2 folds. The mayflies showed higher susceptibility to organophosphates than to pyrethroids. The SRs of Anopheles sinensis to E. orientalis were 514 to 1,438 fold higher for organophosphates (LD50 values of 0.05 to 0.23μg/♀) and 62 to 1,155 fold higher forpyrethroids (LD50 values of 0.13 to 2.41μg/♀). The SRs of Culex pipiens to E. orientalis were 606 to 3,595 fold higher for organophosphates with LD50 values of 0.02-0.17μg/♀ and 81 to 1,365 fold higher for pyrethroids with LD50 values of 0.11- 1.83μg/♀. These results indicate that the use of ineffective insecticides will result in unsatisfactory control against field populations of the subimagoes and adults of E. orientalis. This work was supported by a research grant from the National Vector Control and Surveillance work performed by the Korean National Institute of Health.

This study analyzed effects of different sound treatments in frequencies and intensities on digestion and immune physiological processes of the beet armyworm, Spodoptera exigua larvae. Without effect on egg hatch, sound treatments with 100-5,000 ㎐ at 95 ㏈ suppressed feeding behavior and inhibited a digestive enzyme activity. In addition, two dimensional electrophoresis of midgut luminal proteins indicated a marked difference of the sound-treated larvae. In response to 5,000 ㎐ at 95 ㏈, larvae showed a significant decrease in hemocyte nodule formation against fungal challenge along with significant suppression in phospholipase A₂ activity in hemocyte and plasma. With increase of sound frequencies, the treated larvae showed an enhanced susceptibility to insecticides. Such sound frequency effect was significantly modulated with different sound intensities. These results suggest that sound treatment may give adverse stress to physiological processes of S. exigua larvae and may be applied to a nonchemical insect pest control.

본 연구에서는 산업부산물인 폐 EPDM을 50mesh 이하로 제조한 미세분말 형태의 R-EPDM(Recycling EPDM)을 주성분으로 아스팔트와 안정성을 높이기 위한 첨가제인 분산제와 유화제 및 폴리머 계통의 유동성 향상제를 혼합한 R-EPDM 개질아스팔트 혼합물의 실내 물성 평가를 수행하였다. R-EPDM 개질아스팔트 바인더의 특성을 파악하기 위해 슈퍼패이브 시험법을 이용하여 바인더의 PG(Performance Grade)등급을 분류하였으며, 선회다짐기를 사용한 R-EPDM 개질아스팔트 혼합물의 배합설계를 통하여 최적아스팔트(OAC) 함량을 결정하였다. OAC로 제작된 R-EPDM 개질아스팔트 혼합물의 소성변형 및 동결융해 저항성을 평가하기 위하여 반복주행시험과 수분민감성시험을 수행하였으며, R-EPDM 개질아스팔트 혼합물의 소성변형 및 수분민감성에 대한 저항성이 일반아스팔트(AP-5) 혼합물보다 우수함을 알 수 있었다.

The purpose of this study was to identify the determinants of decision-making confidence of clothing. As determinants, this study examined consumer susceptibility to interpersonal influence, vanity, and clothing knowledge. Data were collected through surveying university students in Seoul metropolitan area using convenience sampling method. Out of 324 distributed, 300 useful questionnaires were returned. The results showed that identical conformity among consumer susceptibility to interpersonal influence factors significantly influences, both directly and indirectly, decision making confidence through vanity. Although normative conformity does not influence decision-making confidence directly, it does significantly influence decision-making confidence indirectly through influencing vanity and clothing knowledge. The results suggest clothing is a manifestation tool for managing public self, which finally leads to increased clothing knowledge and decision-making confidence of clothing. These findings may be used by marketers in developing strategies for product development and promotion.

This study was conducted to clear the regional difference in the resistance development of the spirodiclofen 36% WP, an acaricide of tetronic acid class, against two-spotted spider mite, Tetranychus urticae occurred in apple orchard since 2007. Two-spotted spider mite was collected from eight regions in the Chungnam, Chungbuk and Gyeongbuk that were major apple cultivation in Korea. An bioassay was investigated the ovicidal activity to compare with the degree of resistance development of this pest. The managed orchard in Sancheok-myeon, Myeongseo-ri, Chungju was controlled by several different acaricides from 2001 to 2008, and spirodiclofen WP was used for the last seven years. LC50 of spirodiclofen WP was estimated as 19.4 ppm in managed orchard, it showed as high as 2.6-fold (resistance ratio) comparing to those of susceptible strain showed as 7.5 ppm. LC50 of spirodiclofen WP against etoxazole-resistant two-spotted spider mite, gained from Chungbuk National University, was proved in 8.1 ppm. This observation indicates that spirodiclofen WP did not occurred in cross resistance with etoxazole SC. Other two regions in Chungju, the resistance ratio against spirodiclofen WP showed as 2.5- and 2.3-fold, respectively. In Chungnam, Gyeongbuk, it has been limited the resistance ratio under 3-fold, respectively.

The susceptibility of the Blattella germcanica (L.) in the Republic of Korea (ROK) to insecticides was evaluated under laboratory conditions using 12 insecticides currently used by the local public health centers and/or pest control operators in the ROK. The insecticides included seven pyrethroids and five organophosphages. Based on their LD50values, the order of susceptibility of B. germanica adults to the insecticides was chlorpyrifos-methyl, profenofos, and chlorpyrifos with the values of 0.07, 0.29, and 0.88 ㎍/♀, respectively. The least susceptibility was obtained with tetramethrin at LD50 of 7.39 ㎍/♀. In the comparative resistance test, the resistance ratios (RR) of 12 insecticides were compared to each other using field collected B. germanica adults in Seoul between 1993 and 2007. Blattella germanica demonstrated higher RRs to pyrethroids such as λ-cyhalothrin, and low RRs among the organophosphates. Among the pyrethroids, λ-cyhalothrin had the highest RRs of 111 and 129 fold differences at LD50 and LD90 values, respectively. Among the organophosphates, profenofos was observed to have the highest RRs of 4 and 15 fold differences at LD50 and LD90 values, respectively. However, there were no significant differences in susceptibility to tetramethrin, chlorpyrifos, and fenitrothion. Blattella germanica was more susceptible to pyridafenthion showing a 0.7 fold difference in a resistance rate (RRLD50), respectively. Resistance ratio of tetramethrin was low, but susceptibility was also not high.