• Journal of Bio-Environment Control
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• v.27 no.3
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• pp.239-244
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• 2018

The effect of the trap equipped with diverse light-emitting lamp on the lure efficiency of whitefly (Trialeurodes vaporariorum) was investigated in the greenhouse cultivating tomato. The light-emitting lamp type equipped to trap was blue, yellow, and white light-emitting lamp. The experiment results showed that trap equipped with blue light-emitting lamp captured the most number of $110{\pm}3.2$ adult whitefly and the number of captured adult whitefly was $71{\pm}1.4$ at yellow light-emitting lamp trap and $45{\pm}1$ at white light-emitting lamp trap respectively. The wavelength distribution band of blue light-emitting lamp was between 330 nm and 430 nm. The wavelength band of yellow and white light-emitting lamp contain repellent wavelength band at the same time. These results show that the trap equipped with blue light-emitting lamp could be used effectively for whitefly control and prevention in the greenhouse cultivating tomato.

• Korean journal of applied entomology
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• v.21 no.4 s.53
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• pp.200-206
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• 1982

A computer simulation model was constructed to explore the phonology of the Striped Rice Borer, Chilo suppressalis (Walker), in Korea. The phenological system model based on the concept of distributed time delay was written in the computer program 'INSECT' and simulated with the estimated parameters of the effective day-degrees (DEL) and the order of time delay (K) for determining the validity of the system model. The accumulated emergence curves obtained from the phenological model were slightly different from the observed light trap data at the early and late stage of the moth emergence in 1978. The differences between observed and simulated $50\%$ emergence date were five to six days in the locations of Suweon and Chuncheon, while it was only two to three days in Iri, Daegu, Boseong, and Milyang. The phenological model should be further improved for simulation of field population changes by adding the information of the time delay process in each developmental stage, the age distribution of overwintered population, and the limiting factors of the borer mortality.

• Korean journal of applied entomology
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• v.49 no.3
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• pp.219-226
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• 2010

This paper presents the occurrence and damage characteristics of the rice leaf-folder populations in the paddy fields of Dangsu-dong, Suwon from 2004 to 2007, and also reports the insecticide response of rice leaf-folder populations, which were collected from 2005 to 2006 in Korea and Vietnam. Laboratory measurements of the head capsule width and body length data enabled the identification of the rice leaf-folder larva stages collected in the field. The rice leaf-folder population in Suwon from 2004 to 2007 has a clear pattern consisting of two different group: the low and high density years. During the low density years (2004 and 2006), only one adult peak was noted in late August, with the damaged-hill percent less than 10% in late July, and the damaged-leaf percent around 2% in September. In contrast, during the high density years (2005 and 2007), two adult peaks were noted in early August and mid-September, with the damaged-hill percent was around 30% in late July, and the damaged-leaf percent 15 to 30% in September, which was beyond the economic injury level of rice leaf-folder. High correlations existed between the occurrence of rice leaf-folder in late July and early August and damages to rice during September. Based on these results, we suggest that the information on the rice leaf-folder population monitored by the adult density or damaged-hill percent in late July and early August would be very useful for predicting the damages later in the season for aiding in decision-making for timely control. In addition, the regional populations of rice leaf-folder showed the similar responses to the insecticides tested: high susceptibility to IGRs (tebufenozide and methoxyfenozide) and organophosphates (chlorpyrifos-methyl, pyridaphenthion), but relatively low to cartap.

• Journal of Korean Society of Forest Science
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• v.103 no.4
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• pp.622-629
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• 2014

This study aims to develop a standard diagnostic table for mountain ginseng so that the cultivators not only can check their current level of management with the table, but also can understand and address operational challenges better by themselves utilizing the table. The standard diagnostic table consists of 3 categories and 18 subcategories to diagnose the general status of forestry households, the indicators of management performance and the level of management. To develop the table, the study conducted a survey on the actual condition of management, targeting 81 forestry households throughout 15 municipalities including Mu-ju, Jeollabukdo, and Ham-yang, Gyeongsangnamdo, all of which are the chief producing districts of mountain ginseng. Then, the study calculated total scores by regions by aggregating the scores of 18 subcategories, in order to evaluate and compare the management level among regions based on the scores. According to the result, the average score of 81 forestry households was 57.2 point-58% of which surveyed belonged to the range of 40-60 point. Compared by regions, the average score of Jeollabukdo regions was 52.9 point, the lowest, and that of Gyeongsangnamdo regions was 61.4 point, the highest. It is remarkable that among the indicators of management base, the average score of 'mounding (the height of mound)' item was recorded rather low with 1.59 point, reflecting the fact that the cultivators tend to raise mountain ginseng with no additional mounds. As for the indicators of production skills, the average score of the pest control item was remarkably low with 1.28 point. Over 90% of cultivators answered that they do not usually forecast or survey the pest disease in advance. Meanwhile, it is also noticeable that the item of sowing and planting methods, and the item of seed were both rather high, recording 4.00 and 4.47 point respectively. As for the item of management and sales skill, however, the score was rather low with 2.20 point, meaning that the forestry households still have a low interest in the business management.

• Korean journal of applied entomology
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• v.42 no.1
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• pp.43-51
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• 2003

This study was carried out to develop the forecasting model of Pseudococcus comtocki Kuwana for timing spray. Field phonology and temperature-dependent development of p. comstocki were studied, and its stage transition models were developed. p comstocki occurred three generations a year in Suwon. The 1 st adults occurred during mid to late June, and the 2nd adults were abundant during mid to late August. The 3rd adults were observed after late October. The development times of each instar of p. comstocki decreased with increasing temperature up to 25$^{\circ}C$, and thereafter the development times increased. The estimated low-threshold temperatures were 14.5, 8.4, 10.2, 11.8, and 10.1$^{\circ}C$ for eggs, 1st+2nd nymphs, 3rd nymphs, preoviposition, and 1st nymphs to preoviposition, respectively. The degree-days (thermal constants) for completion of each instar development were 105 DD for egg,315 DD for 1st+2nd nymph, 143 DD for 3rd nymph, 143 DD for preoviposition, and 599 DD for 1 st nymph to preoviposition. The stage transition models of p. comstocki, which simulate the proportion of individuals shifted from a stage to the next stage, were constructed using the modified Sharpe and DeMichele model and the Weibull function. In field validation, degree-day models using mean-minus-base, sine wave, and rectangle method showed 2-3d, 1-7d, and 0-6 d deviation with actual data in predicting the peak oviposition time of the 1st and 2nd generation adults, respectively. The rate summation model, in which daily development rates estimated by biophysical model of Sharpe and DeMichele were accumulated, showed 1-2 d deviation with actual data at the same phonology predictions.

• Journal of Veterinary Clinics
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• v.23 no.2
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• pp.105-110
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• 2006

A three-layer, feed-forward artificial neural network (ANN) with sixteen input neurons, three hidden neurons, and one output neuron was developed to identify the presence of infectious bronchitis (IB) infection as early as possible in laying hen flocks. Retrospective data from flocks that enrolled IB surveillance program between May 2003 and November 2005 were used to build the ANN. Data set of 86 flocks was divided randomly into two sets: 77 cases for training set and 9 cases for testing set. Input factors were 16 epidemiological findings including characteristics of the layer house, management practice, flock size, and the output was either presence or absence of IB. ANN was trained using training set with a back-propagation algorithm and test set was used to determine the network's capability to predict outcomes that it has never seen. Diagnostic performance of the trained network was evaluated by constructing receiver operating characteristic (ROC) curve with the area under the curve (AUC), which were also used to determine the best positivity criterion for the model. Several different ANNs with different structures were created. The best-fitted trained network, IBV_D1, was able to predict IB in 73 cases out of 77 (diagnostic accuracy 94.8%) in the training set. Sensitivity and specificity of the trained neural network was 95.5% (42/44, 95% CI, 84.5-99.4) and 93.9% (31/33, 95% CI, 79.8-99.3), respectively. For testing set, AVC of the ROC curve for the IBV_D1 network was 0.948 (SE=0.086, 95% CI 0.592-0.961) in recognizing IB infection status accurately. At a criterion of 0.7149, the diagnostic accuracy was the highest with a 88.9% with the highest sensitivity of 100%. With this value of sensitivity and specificity together with assumed 44% of IB prevalence, IBV_D1 network showed a PPV of 80% and an NPV of 100%. Based on these findings, the authors conclude that neural network can be successfully applied to the development of a screening model for identifying IB infection in laying hen flocks.

• Korean journal of applied entomology
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• v.21 no.1 s.50
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• pp.38-48
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• 1982

This study was conducted to investigate the changes in moth occurrence of striped rice barer, Chilo suppressalis (Walker), in relation to climatic factors, rice varieties, and cultural practices. The light trap data from 41 forecasting stations for 14 years from 1966 to 1979 were analyzed by means of the changes in the time and amount of borer occurrence in connection with the introduction of new rice varieties, the accumulated effective day-degree and its variation for completing one generation, and the climatic factors affecting the moth occurrence. The total number of moths caught by light traps in both spring and summer generations were considerably decreased with the wide cultivation of new rice varieties. In fact, the spring moths were remarkably decreased since the new varieties were introduced in 1972. The occurrence ratio of summer moths against the preceeding spring moths was higher in the middle region and middle southern mountainous area than the other regions. Its high ratio of regions was annually expanded from the middle region to the southern region. The $50\%$ emergence dates of both generations were later in the southeastern region than in the middle region. The ecological characteristics were clearly shown between the northern and southern region of Chupungryeong in terms of the occurrence of summer moths, the ratio of occurrence of summer moths to the preceeding spring moths, and $50\%$ emergence dates of the summer moths during the years of $1977\~1979$. The ratio of the summer moth occurrence to the preceeding generation was negatively correlated with the average temperature in lune and July, respectively, and the average precipitation in late June. The ratio of spring moth occurrence over the preceeding generation was positively correlated with the average temperature in September, October, November, and March, respectively, whereas it was negatively correlated with the average precipitation in early September and March, and the average humidity in early May. The effective day-degree for one generation was in the range from 600 to 900 DD at upper threshold $30^{\circ}C$ and lower threshold $10^{\circ}C$.

• Korean Journal of Environmental Agriculture
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• v.22 no.4
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• pp.246-250
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• 2003

In order to preserve the soundness of agro-ecosystem and products safety in agriculture, this study was evaluated environmental impact in relation to the INM (Integrated Nutrient Management) and IPM (Integrated Pest Management) at paddy fields at Ok-Chun and Yang-Pyung region. By introduction of INM with the application of BB(bulk-blanded) fertilizer based on soil analysis and IPM, the application rate of fertilizer was reduced to about $28.6{\sim}39.4%$ and the yield of brown rice was increased to about $3{\sim}10%$ compared to conventional practices. The concentrations of COD, $NH_4-N$, and $NO_3-N$ in irrigation water flowed to the environmental-friendly agriculture practices were 15.0, 0.67, and 1.39 mg/L, respectively. The concentrations of COD, $NH_4-N$, and $NO_3-N$ from paddy fields in drainage water were 12.4, 0.29, and 2.42 mg/L, respectively. The total number of the freshwater invertebrates was higher in field treated with fertilization by prescription with soil testing. Also, the population density of aquatic insects was higher than the other fields at both demonstration villages. In conclusion, it was possible to reduce the amount of fertilizer and agricultural chemicals application, and increase the yield of rice by application of the environmental-friendly agriculture practices.

• Korean journal of applied entomology
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• v.30 no.4
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• pp.249-257
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• 1991

Chronological changes in the occurrence pattern of the striped rice borer(SRB), Chilo suppressalis Walker, were investigated by analyzing the data collected by 33 light traps of the countrywide monitoring units during the period of 1968-1989. And also relation of incidences between larval and adult populations, emergence time and percent emergence of overwintered larvae were observed in relation to the time of different rice transplantations. Spring moths of SRB in 1985-'89 generally emerged earlier than in 1968-'72 : 30 days earlier at Kwangju, 20 -25 days earlier at Sangju and Naju, 10-15 days earlier at Uljin, Jinju, Goyang, Milyang, Kimhae, etc., 5 days earlier at Suweon, Jinchun, Daejeon, Namweon, Haenam, etc. There was no change in the time of spring moth emergance at Weonseong, Chungju, Seosan, Yongju, and Nonsan. Summer moths of SRB in 1985- '89 also emerged earlier than 1968- '72: 20 days earlier at Uljin, 15 days earlier at Chungju, Yeongdug, and Habchun, 5-10 days earlier at the other areas except Yeongju. There was an overall countrywide decrease in the population of the 1st generation of SRB during the last two decades. The population of the 2nd generation also decreased in 19 areas during the same period, but increased in 14 areas including over 3-fold increases in Kwangju, Naju and Daegu, and double increase in Jinju, Milyang and Gongju. The higher larval population density of 1st genration was taken place in the earlier transplanted fields, whereas the population of 2nd generation were higher at mid-season transplanted (May 30), followed by May 15, June 15, and April 30. The peak of larval population appeared generally 15 days after moth peak in 1st generation, and 10 days after moth-peak in 2nd generation. The earlier transplanted fields were the higher percent damage due to 1st off-springs of spring moths, whereas the fields transplanted in mid-season were higher damage due to 2nd off-springs of summer moths. Average body weights of SRB larvae before overwintering were 65.6 mg, 61.2 mg, and 55.5 mg in early, mid-season, and late transplantations, respectively. In field cage experiments, emergence rate of the overwintered larvae ranged from 28.3-39.8%. In other words, body weights of overwintering larvae were heavier in fields by earlier transplantation, and heavier larvae showed higher percentage of adult emergence. The period from overwintered larvae to adult emergence was longer in the fields of the later transplantations; namely, 44, 49, and 51 days for early, mid-season, and late transplantations, respectively.