• Journal of Ecology and Environment
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• v.47 no.4
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• pp.250-260
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• 2023

Background: Crabgrass (Digitaria ciliaris, Poaceae) is a globally distributed weed, including in Afro-Eurasia, America, and Australia. As a highly gregarious plant, crabgrass is an important habitat for a diverse array of insects, and a potential habitat for agricultural pests. To compare the insect communities associated with the crabgrass community, insects were sampled using sweep sampling (100 sweeps per sample) at five sites, including Daejeon (Daejeon and Gap rivers), Anseong, Namhae, and Inje, with a focus on the Daejeon River. Results: A total of 5,888 individual insects belonging to eight orders, 42 families, and 115 species were collected from the five sites. Both the number of species and individuals of Hemiptera were the highest at all of the sites. In the present study, 73% of the insect population fed on D. ciliaris as a host plant. The dominant species in the D. ciliaris community was Laodelphax striatellus (Delphacidae), being ubiquitous at all the sites which showed a high abundance of rice pests in the communities and the suitability of D. ciliaris as an alternative host plant for them. The Shannon-Wiener diversity index was highest in Inje on 17 September (2.88), and the Chao1-bc diversity index was highest in the Gap River on 5 September (80). The sampling efficiency of 100 sweep samples (sample coverage) was calculated to be as high as 90%. The results of the samples taken from September to November in the Daejeon River showed that the number of species and individuals decreased gradually over time, and the number of dominant species decreased sharply between September and October. Similarity analysis indicated that sampling dates that were closer together yielded sampled assemblages with higher faunal similarity. In addition, in each sampling, the difference in the minimum temperature during the two-week period prior to sampling and faunal similarities were negatively correlated. Conclusions: This study provides foundational data that could enhance our understanding of insect diversity in D. ciliaris. The data can facilitate ecological conservation and management of Korean grasslands generally, as well as identification of potential pests that may disperse from D. ciliaris communities to nearby farmland.

• Journal of Applied Biological Chemistry
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• v.44 no.1
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• pp.23-26
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• 2001

The insecticidal activities of 30 aromatic plant extracts against four insect pests were examined by direct contact application. Against Nilaparvata lugens female adults, Myzus persicae female adults, and Plutella xylostella larvae, at 5,000 ppm, >90% mortality was achieved in the methanol extracts of the rhizomes from Cnidium officinale, Acorus gramineus, Acorus calamus var. angustatus and Curcuma Ionga, the whole plant from Agastache rugosa, the fruits from Illicium verum and Piper nigrum, and the flower bud from Eugenia caryophyllata as well as Cinnamomum camphora steam distillate. Against Spodoptera litura larvae, all test plant extracts were ineffective. The plants described merit further study as potential insect-control agents against insect pests.

• Mycobiology
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• v.39 no.4
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• pp.313-316
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• 2011

The ambrosia beetle, Platypus koryoensis, is a serious pest of oak trees in Korea. In this study we investigated filamentous fungi present in the body of the beetle. Fourteen genera of filamentous fungi belonging to Ascomycota and Basidiomycota were isolated. Among the isolated fungi, some were able to produce wood degrading enzymes. This is first report of fungi associated with P. koryoensis.

• Korean journal of applied entomology
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• v.49 no.2
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• pp.97-103
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• 2010

In this study, 5 species (Tetranychus kanzawai Kishida, Endoclyta excrescens (Butler), leaf roller caterpillar (Adoxophyes orana Fisher), Anomis mesogona (Walker), and Aulacaspis rosae (Bouche)) were found in Rubus coreanus Miquel in Jeonbuk province, from 2006 to 2008. T. kanzawai appeared in mid-May and showed three peaks in late June, mid-July, and late August. Its density was over 10 adults per leaf. A. mesogona appeared in mid-June and showed two peaks in late July, and early October. Of the 28 insect pests in pre-harvesting, the 7 main species were T. kanzawai, T. urticae, A. orana, Lygocoris lucorum Meyer, Frankliniella intonsa (Trybom), Psylliodes punctifrons Baly and Motschulskyia serrata (Matsumura). Of the 19 insect pests in after-harvesting, the 6 main species were T. kanzawai, E. excrescens, A. mesogona, A. orana, P. punctifrons and A. rosae. Growth of R. coreanus decreased when insect pests were not managed and yields decreased approx. 7% a year. Management of insect pests in field using pesticide was not different.

• Korean journal of applied entomology
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• v.45 no.3 s.144
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• pp.371-373
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• 2006

Life history of Ivela auripes (Lepidoptera: Lymantriidae), a pest of Cornus controversa, was investigated both in laboratory and field condition. At $24{\pm}1^{\circ}C$, developmental period from larvae to adult and adult life span was $26.3{\pm}0.3$ and $4.4{\pm}0.2$ days, respectively. Developmental period of pupae reared in the laboratory was not significantly different from those collected in the field. Female moths reared in the laboratory laid significantly less eggs than those emerged from the pupae collected in the field. Light trap catches was less effective than direct monitoring in the field. The two monitoring results showed that adult moth emerged from early June to late June, and the time of 50% cumulative emergence was 17 June.

• Journal of Korean Society of Forest Science
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• v.95 no.3
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• pp.256-260
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• 2006

This study was conducted to investigate the effect of parasititoids on the density-fluctuation of the pine needle gall midge, Thecodiplosis japonensis. The density of T. japonensis and its parasitoids was observed by emergence trap in pine forest in Namsung-dong, Keumho-eup, Youngcheon-shi, Kyeongsangbuk-do, Korea, from 1986 to 2005. After 1987, density fluctuations of adults pine needle gall midge and its parasitoids showed similar trends and density of parasitoids was dependent on density of host population. Sex ratio of the pine needle gall midge, T. japonensis, was female-biased and had some variations in according to years. These trends were similar to those of parasitoid populations and sex ratio of Inostemma seoulis was more female-biased than that of I. matsutama. T. japonensis adults emerged in the field from May 16 to July 27 and the peak of emergence was between late May and early June. The adults of Inostemma matsutama emerged from May 16 to June 11 (peak between late May and early June), whereas those of Inostemma seoulis emerged from June 9 to July 27 (peak: late June).

• Korean journal of applied entomology
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• v.44 no.2
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• pp.157-159
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• 2005

The number of winter buds oviposited by Drycosmus kuriphilus against chestnut varieties was lower of Ishizuchi and Daap than that of Okkwang, Tsukuba and Arima. D. kuriphilus oviposited multiful eggs in each winter bud of most of the chestnut varieties tested. More than three eggs were oviposited on winter bud of lower shoot of native, Tsukuba, Okkwang and Pyounggi varieties. However, average laid eggs less than one were on winter buds of Tshizuchi and Daap. Number of eggs oviposited in winter bud on lower shoot was higher than those on upper one. More than 15 eggs were oviposited in Tsukuba, whereas one or less egg was oviposited in Daap. Rates of winter buds oviposited by D. kuriphilus in native, Arima and Tsukuba were 83.8, 78.5, and $75.9\%$, respectively.

• Korean journal of applied entomology
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• v.46 no.2
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• pp.275-280
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• 2007

This survey was conducted to illustrate insect pests and their natural enemies in soybean fields in Honam area. A total of 23 pest species in 13 families and 13 species of natural enemy were observed during 2002 to 2003. Delia platura, Medythia nigrobilineata, Spodoptera exigua and Aphis glycines occurred relatively with high population densities during the early growth stage of soybean. Dolycoris baccarum, Riptortus clavatus, Nezara antennata, Piezodorus hybneri and Halyomorpha halys began to occur between mid July to early August and lasted until the harvest time. Lepidopteran insect pests, Leguminivora glycinivorella, Pleuroptya ruralis, Scopula missaria, Macdunnoughia purissima and Spodoptera litura occurred significantly in late August in soybean field. Natural enemies of soybean insect pests observed in this survey were seven parasitoids, five predators, and an entomopahogenic fungus. Two egg parasitoid species for R. clavatus, two parasitoid species for P. ruralis, and five natural enemy species (including parasite, predator and entomopathogenic fungi) for either S. litura or A. glycines were identified, respectively. Among them two egg parasitoid species, Gryon japonicum and Ooenyrtus nezarae for R. clavatus, for and one parasitoid species for P. ruralis, that belong to Bethylidae, were new to Korea.

• 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.

• Korean journal of applied entomology
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• v.58 no.3
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• pp.239-249
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• 2019

This study was carried out to compare on the time of occurrence of 6 major rice insect pests [Lissorhoptrus oryzophilus Kusche, Oulema oryzae Kuwayama, Sogatella furcifera (Horvath), Nilaparvata lugens Stal., Cnaphalocrocis medinalis (Guenee), Mythimna separata Walker] in northern part of the Korean peninsula. Using growing degree days of the insects, we evaluated the number of occurrence generations and the time of occurrence. Over-wintering insects such as L. oryzophilus and O. oryzae showed different occurrence periods in northern regions. The occurrence period of the first generation adults was later in northeast regions than in Korean middle regions and more later both in northern alpines and in northern parts of east sea. In addition, the first adults of S. furcifera, N. lugens, C. medinalis, and M. separata occurred between June and early August. However, from late August to September, these insects showed the different occurrence periods in northern regions. Especially, the second adults of N. lugens were not occurred and the second to third generation adults of S. furcifera, C. medinalis, and M. separata showed similar occurrence properties. Based on these properties, the occurrence of major rice insect pests will be less in northeast regions, northern regions of east sea, northern inlands, and northern alpines of the Korean peninsula. However, comparing with their occurrences in northern regions of Gyenonggi and Gangwon provinces, the rice insect pests may show similar occurrence pattern in mid-korean mountains except for pyunggang and yangduk regions as well as in the southern and northern regions of Suyang-san.