• Korean journal of applied entomology
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• v.39 no.2
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• pp.73-82
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• 2000

Two Psyllidae species of Cacopsylla pyricola (Foerster) and C. pyrisuga (Foerster)damaging pear trees have been reported in Korea. However, their ecological characteristics and damagepatterns have not been evaluated yet. To establish basic control measures of C. pyricola, field phenology,overwintering ecology, seasonal fluctuation and temperature-dependent development of C. pyricola wereexamined. C. pyricola overwintered under the bark scale of pear trees as winter form adults and theymoved to fruiting twigs from mid-February. Honeydew produced by C. pyricola nymphs and adults asthey feed caused serious black sooty mold on leaves and fruits. The seasonal occurrence of C. pyricolawas different every year. In 1993, characterized by cold temperature and heavy precipitation, C. pyricolapopulation was maintained highly during growing season. However, the population was decreased rapidlyfrom early July in 1994, year of hot and dry weather condition. In 1995, year of average temperature, thedensity of C. pyricola population was decreased during hot months of July and August, and rebuilt up inSeptember and October. The development periods of C. pyricola eggs were 13.33 days at 15"C, 9.32 daysat 20$^{\circ}$C, 7.82 days at 25"C, 6.60 days at 30$^{\circ}$C, and 7.75 days at 35$^{\circ}$C. The development periods ofnymphs were 33.75 days at 15OC, 23.77 days at 20$^{\circ}$C, 15.21 days at 25"C, and 17.40 days at 30$^{\circ}$C. Theirdevelopment periods and mortalities were increased in higher temperatures. The parameters of nonlineardevelopment model, Weibull and linear development models of Cacopsylla pyricola were estimated.models of Cacopsylla pyricola were estimated.

• Korean journal of applied entomology
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• v.53 no.3
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• pp.311-315
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• 2014

Lantern fly(Lycorma delicatula) is a major invasive pest that causes withering symptom of agricultural crops by sucking tree sap and sooty mold symptom by producing honeydew. This study was conducted to investigate the occurrence pattern of lantern fly in grape orchards in Gyeonggi area and the effect of winter temperature on L. delicatula egg survival during 2010 to 2013. In Gyeonggi areas, overwintered L. delicatula eggs began to hatch from early May and nymphs peaked in mid May. Adults emerged from late July and laid eggs until early November. The survival of L. delicatula eggs during overwintering was largely affected by winter temperatures. The relationship between the number of days below a threshold temperature (x) in January and the survival rate of overwintering L. delicatula eggs (y) was using linear regression model. The best model selected by the lowest RSS (residual sum of square) between predicted and actual survival was y = -1.0486 x + 94.496 ($R^2=0.7067$) with $-11^{\circ}C$ of threshold temperature. These results should be helpful to conduct L. delicatula management programs, since the results provided relivable prediction for the winter survival of L. delicatula eggs and the phenology of egg hatch in the spring.

• Korean journal of applied entomology
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• v.44 no.3 s.140
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• pp.219-223
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• 2005

Torymus geranii was found to be a ectoparasitoid attacking the larvae of Dryocosmus kuriphilus. T. geranii has longevity of a $42.8{\pm}9.8$ days at $20^{\circ}C$ and $26.5{\pm}11.0$ day at $25^{\circ}C$ under conditions supplied with 100% honeydew. Oviposition numbers at 20 and $25^{\circ}C$ were $22.3{\pm}12.5$ and $42.2{\pm}18.4$, respectively. The eggs were oval in shape, measuring $0.56{\pm}0.33$ mm in length. The larvae, $2.94{\pm}0.18mm$ in length, was white and length of male and female pupae were $2.01{\pm}0.18mm$ and $2.73{\pm}0.09mm$, respectively. T. geranii had two generations with overwintering generation emerged on late May to early June at Chunchon, central part of Korea, however showed three generations with overwintering generation emerged on middle May to early June, the first one on late June to early July, and the second one on late July to earlyl August.

• Journal of Life Science
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• v.29 no.2
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• pp.202-208
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• 2019

Brown planthopper (BPH), Nilaparvata lugens Stål (Hemiptera: Delphacidae), is one of the most important migratory pests damaging rice in Korea. It invades annually from tropical and subtropical areas via continental air streams. It is necessary to determine the resistance levels of rice varieties in order to control efficiency. The honeydew excretion, development, and reproduction of the migratory BPH were studied by region in a laboratory at $25{\pm}2^{\circ}C$ and $65{\pm}5%\;RH$ and a 16L: 8D photoperiodism conducted on three BPH resistant genes: Bph1, Bph2, and Bph18. The information obtained was reported using the jackknife method, and we created life table statistics accordingly. The feeding amount of Bph1 resistant gene was lower than that of resistant genes. The developmental periods of immature stages ranged from $13.7{\pm}0.10d$ on Bph2 (Namhae, 2015) to $18.5{\pm}1.06d$ on Bph2 (Sacheon, 2016). Reproductive period and female longevity were longest on the non-resistant genes, Bph2 and Bph18 (except 1980s), and the highest fecundity of N. lugens was observed on the two BPH resistant genes. Highest net reproductive rates ($R_0$) were calculated on Bph2 by region. Intrinsic rates of population increase ($r_m$) showed a difference in resistant genes by region. These population parameters showed that migratory regions and biological characteristics of N. lugens vary annually.

• Journal of the Korean Institute of Landscape Architecture
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• v.39 no.6
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• pp.98-109
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• 2011

Habitat restoration initiative is an important factor for the on-site preservation of butterflies. A new habitat necessitates the investigation of the ecology of the butterfly, the landscape of the habitat, the work process, and a cost analysis. In this study, these factors were analyzed through1) re-consideration of the secured results from three years of field work, and 2) a habitat area estimation conducted according to the presence or absence of larvae and adults via a Parnassius bremeri Bremer survey. The investigation of the natural habitat, done for both larvae and adult butterflies found in South Korea, suggested that multiple patches with a minimum size exceeding $300m^2$ and with an average size of about $1,600m^2$were required for survival of this butterfly. Therefore, more than five patches should be considered for butterfly habitat and patches should have similarity to the present habitat environment with transplantation plans for diet plants and honeydew plants. In addition, to activate the migration of the butterfly, cutting down trees that are obstacles to migration, minimizing the distance between patches and the addition of a stepping patch are also required. A patch connectivity analysis showed that patches should be located within 300m of neighboring patches, as the migration of the butterfly will fail if it is more than 600m. Additionally, more than $10,000m^2$ for a single patch or a patch network composed more than five patches over $1,600m^2$ in size were recommended, with a total patch size of $8,000m^2$. Additionally, neighboring multiple patch networks are more desirable than a single habitat in the event a cyclic habitat pattern arises. In this study, we suggest a habitat restoration and optimal prerequisites for a butterfly habitat. It is expected that this research will lead to the creation of a good model for the restoration of butterfly species.

• Korean journal of applied entomology
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• v.23 no.4 s.61
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• pp.221-232
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• 1984

A series of experiments were carried out in the laboratory and fields to reevaluate the effects of Padan (cartap) to the brown planthopper (BPH). Nilapanata lugens. The $LD_{50}\;land\;LC_{50}$ values for the female and male BPH were determined by the topical application and seedling- dipping/root -soaking methods. The values were differed with the sex and test methods, and the BPH mortality was greatly increased with a rise in temperatures $(25-35^{\circ}C)$. In a viewpoint of honeydew excretion and offsprings produced, there was no any possibility in BPH resurgence at the sublethal exposures of Padan. The BPH mortality to Padan 4 G was greatly low in the pot tests compared with those to diazinon and carbofuran, but in the paddy fields the efficacy of Padan 4G was nearly reversed. A single application of Padan 4G at the rate of 4kg/10a dramatically suppressed the BPH populations in the paddy fields, and the control effect was much more accelerated in the drained paddy field than in the submerged paddy field.

• Korean journal of applied entomology
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• v.25 no.3 s.68
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• pp.139-149
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• 1986

These experiments were performed to investigate the effects of sublethal doses of fungicides (validamycin A 3 Sp and neoasozin 6.5 Lq) and insecticides (diazinon 34Ec and decamethrin 1Ec) on the possible ways to the resurgence of brown planthoppers (BPH) (Nilaparvata lugens $St{\aa}l$). The possible factors tested in this experiment were fecundity of BPH, longevity, egg-hatchability, amount of honeydew excreted, population build-up following the pesticide treatments in the next generation, and hopperburn rate of potted rice plants. Among the insecticides tested, the applications of diazinon and decamethrin in rice fields may induce the BPH resurgence and accelerate the hopperburn of rice plants through stimulating the fecundity, increasing the adult longevity, promoting the feeding activity and causing the positve population build-up of the BPH