Population dynamics of Tetranychus urticae and its predatory mites, Neoseiulus californicus and Phytoseiulus persimilis, on connected strawberry leaf arena

JeongJoon Ahn,Joon-Ho Lee 한국응용곤충학회 2008 한국응용곤충학회 학술대회논문집 Vol.2008 No.10

The two-spotted spider mite, Tetranychus urticae Koch, is one of major pests in greenhouse strawberry. Two predator mites, Neoseiulus californicus (McGregor) and Phytoseiulus persimilis (Athias-Henriot), have been widely used for control of T. urticae because they have good functional and numerical responses and searching behaviors. The study of single species releasing and combined releasing of two predatory mites, N. californicus and P. persimilis, was conducted on connected strawberry leaves. The experiments were run under laboratory conditions, 24±1oC, 50-65% RH, and a photoperiod of 16:8 (L:D) h. The excised leaf disk (diameter 3cm) of two strawberry varieties – Maehyang, Sulhyang– were placed upside down on a water-saturated cotton pad in an aluminum pan (width × length 17.4 × 21.5 cm). Twenty leaf disks were placed on each experimental set and the disks (width × length 4×5 cm.) were connected with each other for dispersing of T. urticae and its predatory mite. There were four different experiments – two strawberry varieties and two treatments (releasing single predatory mite, releasing two predator mites). The experiment sets were covered with plastic cage to protect from invading other insects and mites. All life stages of T. urticae and predatory mites were recorded until all mites were vanished. The data were transformed by ln (x+1). Repeated-measures analysis of variance was used to compare the temporal variation in the overall T. urticae and predatory mite density. The average number of T. urticae per leaf arena was significantly different among treatments in Sulhyang (Treatment, df=3, 196, F=17.86, P=0.0001; Time, df=6, 1176, F=47.76, P=0.0001; Time ×Treatment, df=18, 1176, F=22.06, P=0.0001) and in Maehyang (Treatment, df=3, 196, F=42.07, P=0.0001; Time, df=6, 1176, F=64.51, P=0.0001; Time x Treatment, df=18, 1176, F=24.19, P=0.0001). When N. californicus was introduced to P. persimilis system with diminishing prey, P. persimilis population increased more rapidly than N. alifornicus but P. persimilis was displaced by N. californicus. In single or combined releasing system, N. californicus persisted longer after prey depletion than P. persimilis. We examined population growth of P. persimilis and N. californicus in single and combined predatory mite released system with diminishing prey.

Immobilization and Stabilization of Acylase on Carboxylated Polyaniline Nanofibers for Highly Effective Antifouling Application via Quorum Quenching

Lee, Jeongjoon,Lee, Inseon,Nam, Jahyun,Hwang, Dong Soo,Yeon, Kyung-Min,Kim, Jungbae American Chemical Society 2017 ACS APPLIED MATERIALS & INTERFACES Vol.9 No.18

<P>Acylase (AC) was immobilized and stabilized on carboxylated polyaniline nanofibers (cPANFs) for the development of antifouling nanobiocatalysts with high enzyme loading and stability. AC was immobilized via three different approaches: covalent attachment (CA), enzyme coating (EC), and magnetically separable enzyme precipitate coating (Mag-EPC). The enzyme activity per unit weight of cPANFs with Mag-EPC was 75 and 300 times higher than that of those with CA and EC, respectively, representing improved enzyme loading in the form of Mag-EPC. After incubation under shaking at 200 rpm for 20 days, Mag-EPC maintained 55% of its initial activity, whereas CA and EC showed 3 and 16% of their initial activities, respectively. The antifouling of highly loaded and stable Mag-EPC against the biofouling/biofilm formation of Pseudomonas aeruginosa was tested under static- and continuous-flow conditions. Biofilm formation in the presence of 40,mu g/mL Mag-EPC under static condition was 5 times lower than that under control condition with no addition of Mag-EPC. Under continuous membrane filtration, Mag-EPC delayed the increase of transmembrane pressure (TMP) more effectively as the concentration of added Mag-EPC increased. When separating Mag-EPC and membranes in two different vessels under internal circulation of the culture solution, Mag-EPC maintained a higher permeability than the control with no Mag-EPC addition. It was also confirmed that the addition of Mag-EPC reduced the generation of N-acyl homoserine lactone (AHL) autoinducers. This result reveals that the inhibition of biofilm formation and biofouling in the presence of Mag-EPC is due to the hydrolysis of AHL autoinducers, catalyzed by the immobilized and stabilized AC in the form of Mag-EPC. Mag-EPC of AC with high enzyme loadings and improved stability has demonstrated its great potential as an antifouling agent by reducing biofilm formation and membrane biofouling based on 'enzymatic quorum quenching' of autoinducers.</P>

Dispersal of Tetranychus urticae and its predatory mite on connected strawberry leaves

JeongJoon Ahn,Joon-Ho Lee 한국응용곤충학회 2008 한국응용곤충학회 학술대회논문집 Vol.2008 No.05

The study was conducted to investigate dispersal of T.urticae and its predatory mite on connected strawberry leaves. The experiments were run on laboratory conditions, 24±1℃, 50-65% RH, and a photoperiod of 16:8 (L:D). The excised leaf disk (diameter 3cm) of two strawberry varieties- Maehyang, Seolhyang- were placed upside down on a water-saturated cotton pad in an aluminum pan (width x length 17.4 x 21.5cm). Twenty leaf disks were placed on each experimental set and the disks (width x length 4 x 5 ca) were connected with each other for dispersing of T. urticae and its predatory mite. There were six different experiment sets - two strawberry varieties and three treatments (no predatory mite, releasing Neoseiulus californicus, and releasing Phytoseiulus persimilis). The experiment sets were covered with plastic cage to protect from invading other insects and mites. The investigation was conducted by examining two or three times per week and all life stages of T. urticae and predatory mite were reported until all leaves were occupied by mites. Repeated-measures data were analyzed by MANOVA. The average number of T.urticae per cm2 was no significant difference between two strawberry varieties in no predatory mite system (F=0.65, p>0.4195). Although the external structure of two strawberry varieties is very similar the dispersal rate of T. urticae was different between two strawberry varieties in all experiment sets. However, the number of T. urticae per cm2 was no significant different (df=1, F=1.28, p>0.2628). Within the same strawberry variety T.urticae populations among experiment sets were significant different (df=2, F=14.95, p<0.0001 Seolhyang, df=2, F=15.03, p<0.0001 Maehyang).

Spring emergence pattern and its forecasting of Grapholita molesta (Busck) (Lepidoptera: Tortricidae) in stone fruit orchards

JeongJoon Ahn,Jiwon Kim,Soon Won Lee,Chuleui Jung 한국응용곤충학회 2011 한국응용곤충학회 학술대회논문집 Vol.2011 No.05

The study was conducted to investigate the spring emergence pattern of G. molesta and to forecast the emerging time of overwintering G. molesta on tree fruit orchards. G. molesta is one of major insect pests on fruit trees in Korea. The host range of G. molesta includes many economically important tree fruit plants such as apple, pear, peach and plum. The overwintering G. molesta emerge from late March as an adult lay eggs on the shoot of peach or fruits of apple, plum and peach. Therefore, it is important to understand the biofix and to forecast the emerging peak period of overwintering G. molesta for establishing the pest management strategy. The pheromone trap of G. molesta has been utilized to monitor the population density in apple orchard. The commercial stick trap (GreenAgroTech) and lure (Z8-12:AC, E8-12:Ac, Z8-12:OH, 95:5:1) was set to monitor the population density of G. molesta on each place (56 different fruit orchards). The record of temperature was received from meteorological center close to monitoring orchards. The parameters for forecasting the emerging time and peak period of overwintering G. molesta were calculated from the results of Yang et al (1997 and 2001). Although the estimated biofix of G. molesta was not fitted well, the peak period of overwintering G. molesta was explained by linear regression model. The spring emergence pattern of G. molesta was presented differently related to host plant and geographical location. The peak period of G. molesta at the same mornitoring county was presented differently according to host plant. The synchronization between host plant and G. molesta may be studied to figure out the spring emerging time of overwintering G. molesta.

밀리미터파 통신 시스템을 위한 딥러닝 기반의 저복잡도 빔 관리 기법

이정준(Jeongjoon Lee),이충용(Chungyong Lee) 대한전자공학회 2024 대한전자공학회 학술대회 Vol.2024 No.6

Oviposition Behavior of Tetranychus urticae Koch (Acari: Tetranychidae) on Host Plant Leaves with Different Trichome Densities

YongJun Kwon,JeongJoon Ahn,TaeGyun Kim,Joon-Ho Lee 한국응용곤충학회 2009 한국응용곤충학회 학술대회논문집 Vol.2009 No.05

This study was conducted to determine whether trichome density affects the oviposition behavior of adult female Tetranychus urticae Koch on host plant leaves. Experiments were conducted with twenty replications on the leaf discs of each plant (Pear, 'Niitaka'; Apple, 'Fuji'; Strawberry, 'Meahyang'; 3cm diameter) at 25℃, 60-70% RH and a photoperiod of 16:8 (L:D) h. One female T. urticae was placed on each disc. The number and locations of laid eggs were recorded at 24 h intervals until T. urticae died. The trichomes were distributed along the midrib of abaxial surface of pear leaves but were evenly distributed on that of apple and strawberry leaves. Eggs were mostly laid along the midrib of pear leaf disc, but eggs were laid not only along the midrib but also randomly over the leaf disc of apple and strawberry. Therefore, it appeared that T. urticae preferred to lay eggs on the specific location where trichomes were densely distributed. Further study is needed to quantify how different distribution patterns of T. urticae eggs on different plant leaves affect the efficacy of predatory mites to control T. urticae.

Comparison of Single and Combination use of Neoseiulus californicus and Neoseiulus womersleyi for Control of Tetranychus urticae

TaeGyun Kim,Jeongjoon Ahn,YongJun Kwon,Joon-Ho Lee 한국응용곤충학회 2009 한국응용곤충학회 학술대회논문집 Vol.2009 No.05

This study was conducted to compare the effectiveness of single and combination use of N. californicus and N. womersleyi for control of Tetranychus urticae. The experiment was conducted with 5 replications in kidney bean leaf disc (2.5cm diameter) at 25℃, 60-70% RH, a photoperiod of 16:8 (L:D) h. The inoculation ratio was 5:1 for T. urticae:pytoseiidae mite and treatments are: a, N. californicus:T. urticae (4 adult female:20 adult female) b, N. womersleyi:T. urticae (4:20) c, (N. californicus+N. womersleyi):T. urticae ((2+2):20) d, Only T. ulticae (20). T. urticae population became significantly lower in the treatment plots than in the control plot but the higher egg number of T. urticae was observed in the treatment "b" plot than in "a" and "c" plots. In the "c" plot, lower number of N. womersleyi was observed than N. californicus. The result indicates that single use of N. californicus and combination use of N. californicus and N. womersleyi were more effective than single use of N. womersleyi but, there was no significantly difference between single use of N. californicus and combination use of N. californicus and N. womersleyi for control of T. urticae. Also, N. californicus appears to interfere or outcompete N. womersleyi.

Temperature-dependent development model of Neoseiulus californicus (Acari: Phytoseiidae)

TaeGyun Kim,JeongJoon Ahn,Joon-Ho Lee 한국응용곤충학회 2008 한국응용곤충학회 학술대회논문집 Vol.2008 No.05

The developmental time and survival of immature stages of N. californicus were studied under laboratory conditions at nine constant temperatures (12, 16, 20, 24, 28, 32, 36, 38, 40℃), 60-70% RH, and a photoperiod of 16:8 (L:D) h. The total developmental period decreased with increasing temperature between 12 and 32℃, and increased beyond 32℃. Total developmental period of immature stages was longest at 12℃ (18.38 days) and shortest at 32℃ (2.98 days). The cumulative mortality of N. californicus was lowest at 24℃ (4.5%) and highest at 38℃ (15.2%). The normalized cumulative frequency distribution of developmental times for each life stage was fitted to the three-parameter Weibull function (r2=0.91~0.93). The relationship between temperature and developmental rate was fitted by five nonlinear development rate models (Logan 6, Lactin 1, 2, and Briere 1,2). The nonlinear shape of temperature development was best described by the Lactin 1 model (r2=0.98). The determined lower developmental temperature thresholds could be used to predict the occurrence, number of generation and population dynamics of N.californicus on fruit orchards and greenhouse

인버터 병렬 운전의 고조파 순환전류 저감을 위한 PWM 캐리어 위상 불일치 제어 방법

이승용(Seung-Yong Lee),정재정(Jae-Jung Jung),이학준(Hak-Jun Lee),홍찬욱(Chanook Hong),이정준(Jeongjoon Lee) 전력전자학회 2021 전력전자학술대회 논문집 Vol.2021 No.7

Evaluation of the Effective Inoculation Position for Neoseiulus californicus McGregor (Acari: phytoseiidae) for Control of Tetranychus urticae Koch (Acari: tetranychidae) on Apple Branch

TaeGyun Kim,YongJun Kwon,JeongJoon Ahn,Joon-Ho Lee 한국응용곤충학회 2009 한국응용곤충학회 학술대회논문집 Vol.2009 No.05

The objective of this study was to evaluate the effective inoculation position of Neoseiulus californicus for control of Tetranychus urticae on apple branch. This study was conducted under green house conditions. N. californicus was inoculated at different position (Top, Middle and Bottom) of apple branch with a 20:1 ratio (T. urticae:N. californicus). Overall, N. californicus significantly reduced T. urticae numbers in the treatment branches than in the control branch. At 10th day, the T. urticae population was most significantly reduced in the treatment ‘Top’ in which N. californicus were inoculated on the leaf positioned in the top of a branch than in other treatments. At 20th day, most of T. urticae were exterminated in all treatment branches. The daily movement of N. californicus and T. urticae,and their coexistence on apple branch was monitored. Adult N. californicus disappeared from the branch as soon as T. urticae were exterminated in the treatment branches. The result indicates that N. californicus disperse downwards more than upwards in the tree, and the most effective inoculation position for N. californicus for control of T. urticae is the leaves positioned in the top of a branch.