• The Korean Journal of Mycology
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• v.36 no.2
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• pp.153-162
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• 2008

Pinewood nematode (PWN) trapping by nematophagous fungi, Arthrobotrys conoides, A. dactyloides and A. oligospora and the fungal growth were characterized. The three Arthrobotrys species each was inoculated into the PWN cultured on Botrytis cinera fungal colony on potato dextrose agar (PDA). The effects of temperature, pH, PWN inoculation density and nutrients on the growth of the three Arthrobotrys spp were measured. A. conoides grew fast, 13.9 mm/day while A. dactyloides grew slow, 3 mm/day. PDA medium was the best for the fungal growth at $25^{\circ}C$ and pH 4.5. The Arthrobotrys spp growth was stimulated by 500 nematodes inoculation but not by 1000 inoculation. A. dactyloides did not grow below pH 4.5 and at high PWN density. A. conoides and A oligospora formed trapping organs with thick constricting hyphal network only when PWN present, while A. dactyloides formed the organ with circular hyphae constitutively. A. conoides formed trapping organs faster than A. oligospora did. The nematode trapping hyphae of the fungi penetrated into PNW inside to form many tiny infection bulbs and to digest the nematode. However, A. dactyloides formed a few trapping organs but no trapping was observed. Infection rate of PWN was 95% by A. conoides, 80% by A. oligospora and 92% by the combination inoculation of A. conoides and A. oligospora. In contrast A. dactyloides increased PWN density without infecton. There was no interaction effect in any combination inoculation of the three Arthrobotrys spp. A. conoides enhanced PWN infection rate by rapid hyphal growth and early trapping, while A. oligospora did it by increasing hyphal density. In conclusion A. conoides is the most effective in both hyphal growth and infection, and thus these characteristics can be utilized as a biological control of PWN.

• The Korean Journal of Pesticide Science
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• v.15 no.3
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• pp.269-277
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• 2011

Recent outbreak of new diseases and pests which were introduced from abroad, seriously hampered both quality and safety of paprika fruits. This study has been carried out to aid an establishment of guideline for safe use of pesticides and reduction of their residues on paprika. Systemic fungicides boscalid and pyraclostrobin of either mixed (a.i.; 13.6+6.8%) or single (a.i.; 47 and 18.8%, respectively) water dispersible granule formulation(WG) products were sprayed with recommended or double dosage on paprika grown in green house at March and June. To draw pre-harvest residue limit, residues of each fungicide were analyzed from fruits collected eight times from 18 to 1 day pre-harvest. The biological half-lives of both boscalid and pyraclostrobin in mixed formulation in March and June were slightly shorter than those of single formulation which ranged from 14.4 to 20.1 days. Residue levels of both fungicides of single formulation in fruits in June were about one lower compared to those in March. However, application of double dosage frequently exceeded MRLs from fruits grown both seasons. These results showed that residue levels on fruits persisted longer period of time, more than two weeks, and so the case applied in winter season. The dissipation of fungicides on leaves and fruits was compared. The distribution of both fungicides in leaves was 20-200 times higher than that of fruits and persisted up to 18 days of pre-harvest period at the concentration of 10-40 ${\mu}g\;g^{-1}$. This study indicated that the mixed formulation product exhibited low residues in fruits, but high and long enough to pathogen growth in leaves.

• The Korean Journal of Pesticide Science
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• v.14 no.1
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• pp.54-64
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• 2010

Effects of thirteen essential oils (anise oil, clove oil, marigold, mustard oil, neem oil, quassia, quilaja, rosemary oil, rotenone, tea tree extract, thyme oil, wintergreen oil, and yucca) and caffeine on typical industrial insect, silkworm (Bombyx mori) and two entomopathogenic nematodes, Steinernema carpocapsae GSN-1 strain (Sc) and Heterorhabditis sp. Gyeongsan strain (Hg) were investigated in the laboratory. When 1,000 ppm of each essential oils was treated, neem oil showed the highest insecticidal activity against silkworm. Mortality of silkworm fed on neem oil treated mulberry leaf was 55.3 and 100% 5 and 10 days after treatment, respectively. The silkworm fed on neem oil treated mulberry leaf did not make cocoon and pupa. Weight of cocoon and pupa was low in rotenone treatment showing 0.27 g and 1.01 g, respectively. Mustard oil had the highest nematicidal activity against entomopathogenic nematodes. 20 ppm of mustard oil resulted in 69.0% and 100% mortality of Sc and Hg 3 days after treatment, but 4% and 36% at 5 ppm in X-plate, respectively. Mortality of baited Galleria mellonella larva by Sc was not different from control at the concentration of 100 ppm of mustard oil while 30% lower in Hg in sand barrier. Mean numbers of established infective juveniles of Hg in Galleria larva were lower than Sc in sand barrier. Survival rate of Sc was similar to control at the concentration of <200 ppm of mustard oil in sand barrier.

• Journal of Life Science
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• v.17 no.4 s.84
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• pp.510-514
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• 2007

This study was carried on cool and RT(room temperature) storage of unhulled rice. In RT storage of an analysis of coefficient relation, high significant positive coefficients were observed in toyo index and breakdown, setback and protein content. high significant negative coefficients were showed setback and breakdown, breakdown and protein content. In cool storage of an analysis of coefficient relation, high significant positive coefficients were observed in toyo index and amylose content and gelatinization start temperature and protein content and high significant negative coefficients were showed toyo index and whiteness, toyo index and gelatinization start temperature, gelatinization start temperature and amylose content. In RT storage of a path coefficient analysis, a highest positive direct influence was observed in amylose content and a highest negative direct influence was protein content. Positive indirect influence was high revealed breakdown and protein content and negative indirect influence was gelatinization start temperature and Mg/K ratio. In cool storage of a path coefficient analysis, a highest positive direct influence was whiteness and a highest positive indirect influence was gelatinization start temperature. Positive indirect influence was high revealed gelatinization start temperature and amylose content, negative indirect influence was whiteness and gelatinization start temperature. In RT storage of Multiple regression equation of Toyo index based on physicochemical properties of unhulled rice, a highest coefficient of determination was revealed among five facters of whiteness, protein content, Mg/K ratio, amylose content and gelatinization start temperature. In cool storage of Multiple regression equation of toyo index based on physicochemical properties of unhulled rice, highest coefficient of determination was revealed among five facters of moisture content, amylose content, gelatinization start temperature, breakdown and setback.

• Korean Journal of Ichthyology
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• v.26 no.4
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• pp.310-321
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• 2014

Change in fish species composition after the Hebei Spirit oil spill in December 2007 off Taean were determined by analysis of samples collected in Mailpo beach, 10 km south from the oil spill site and polluted by the crude oil. Fish samples were collected by a beach seine in the shallow water at Malipo beach during the low tide of the new moon from February 2008 to December 2009. Five seine hauls were made during the day and the night in each sampling time. Monthly day and night samples did not show the significant differences in species composition. A total of 21 species, 1,032 individuals and 6,544 g of fish were collected in 2008, and 31 species, 4,206 individuals and 35,659 g of fish in 2009. The species collected were composed of the small-sized fish or juveniles. Abundant fishes were the resident species in coastal water, and the migrants were low in abundance. Among the fish occurred, Chelon haematochelius, Sebastes schlegelii, Takifugu niphobles and Pleuronectes yokohamae were predominated in abundance of both years. Monthly fish abundance and species diversity in 2008 were significantly lower than those in 2009. A few number of resident fish were collected from February to June 2008 showing the lowest in May 2008, and fish abundance increased from July 2008. The number of species and abundance of fish in 2009 were increased in spring as the temperature raised, showed a peak in summer and decreased in autumn. This monthly variation in fish species composition and abundance was similar to those in the non-polluted water in other temperate waters. Low fish abundance during several months after oil spill was considered to be related to the residual oil in the water and habitat disturbance due to oil cleaning activity in the beach. Monthly fish species compositions after September 2008 were similar to those of 2009 suggested that the impact on the shallow water fish by the oil residuals was not too significant at least to the fish species composition after September 2008.

• Korean journal of applied entomology
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• v.45 no.2 s.143
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• pp.227-234
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• 2006

For the biological control of the greenhouse whitefly, aphids, American leaf-miners, Encarsia formosa, Aphidius coiemani, Diglyphus isaea, and Dacnusa sibirica were used as biological control factors. Otherwise, many kinds of environment friendly agricultural materials were also used in the kindly environment friendly farming. For testing the toxicity of environment friendly agricultural materials against to insect parasitoids as biological control factors, 61 environment friendly agricultural materials were selected by using methods and periods with insect parasitoids in the greenhouses. Environment friendly agricultural materials were sprayed to mummies and adults of E. formosa and A. colemani, and adults of Diglyphus isaea and Dacnusa sibirica in laboratory condition. Emergence rates were checked during 12 days after spray to mummies of E. formosa and A. colemani, and survival rates were at 24 and 48 hours after viral test for adult parasitoids, with 10% sugar solution. Emergence rates of E. formosa mummies were inhibited by sprayed the fungicidal environment friendly agricultural material (FEFAM) E and the environment friendly agricultural materials contained molybdenum (EFAMMo) G as 0.4 and 2.7%, respectively. E. formosa adults were not survived in vial for 48hours after sprayed and dried with the environment friendly agricultural materials contained plant extract (EFAMPE) J and the EFAMMo C. The environment friendly agricultural materials contained microelements (EFAMMEs) B and EFAMPE H, environment friendly agricultural materials contained useful soil microorganisms (EFAMSMs) H, FEFAM A and FEFAM D were recorded low survival rates of E. formosa adults with 6.7, 13.3, 13.3, 20.0 and 20.0, respectively. In case of the spraying environment friendly agricultural materials to mummies of A. colemani there were low emergence rate from mummies to adults as around 20s % with water spraying as control. A. colemani adults were not survived in vial with EFAMMo C. EFAMPE J, EFAMPE F, EFAMPE H, EFAMSM H were recorded low survival rates under 20% as 6.7, 13.3, 13.3 and 13.3, respectively, D. isaea and D. sibirica adults were not survived in vial with EFAMPE J. EFAMMo C was 53.3% of survival rates in 48 hours vial tests. D. isaea and D. sibirica were not affected by environment friendly agricultural materials compared with E. formosa and A. colemani.

• Korean journal of applied entomology
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• v.22 no.4 s.57
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• pp.237-243
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• 1983

A biological study was done on primary parasites and hyperparasites of cow-pea aphid, Aphis craccivora Koch, collected from Mt. Gyeryong and Daejeon area during the period from April to September 1983 was. The results of mummification of primary parasites, host selectivity between primary parasites and hyperparasites and ratio of mummification, no. of ar chegonia and longevity of important species were obtained as follows; Eight species of Aphidiidae were identified and listed and four of them, Binodoxys nearactaphidis Mackauer, Lipolexis scutellaris Mackauer, Lysiphlebus salicaphis(Fitch)and Trioxys hokkaidensis Takada found for the first time in Korea. Among the 509 mummies collected in the field, adult Aphidiid and adult hyperparasites were $44.8\%,\;and\;43.8\%$, respectively. Lysiphlebus ambiguus, Lysiphlebus salicaphis, Lysiphlebia japonica and Lipolexis scutellaris were a few of important species attacking cow-pea aphid and the rate of their occurrences were $31.6\%,\;18.8\%,\;16.7\%\;and\;11.4\%$, respectively. All the hyperparasites collected from cow-pea aphid were recorded for the first time in Korea; those were Lygocerus testaceimonus Kieffer, Protaphelinus nikolskajae (Jasnosh), Eucoila sp., Gastranscistrus sp., Ardilea convexa(Walker), Asaphes vulgaris Walker. Among the collected hyperparasites, Eucoila sp., A. vulgaris and A. Convexa were dominant species and their occurence rate was $39.9\%,\;34.1\%\;and\;19.7\%$, respectively. As a results of analysis on parasite-hyperparasite interrelationship in cow-pea aphid, Lipolexis scutellaris was attacked from 3 out of 6 hyperparasites and the others was attacked from almost all the hyperparasites. Lysiphlebus ambiguus was higher than Lysiphlebia japonica in the ability of parasitism. There was no difference between Lysiphlebus ambiguus(272) and Lysiphlebia japonica(279) in number of archegonia, but L. ambiguus$(66.9\%)$ was higher than L. japonica$(43.0\%)$ in the rate of mummification to archegonia. The longevity of Aphidiidae and hyperparasites was investigated by feeding honey. The results showed that hyperparasites had lived 15.8 to 21. 5 days, while Aphiidiidae lived only 2 to 3 days.

• Korean journal of applied entomology
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• v.49 no.4
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• pp.277-287
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• 2010

Several species of the genus Aphidius are used in biological control programs against aphid pests throughout the world and their behavior and physiology are well studied. While the importance of sensory organs in their behavior is understood, their antennal structure remains largely unknown. In this study, the external morphology and distribution of the antennal sensilla on the antennal of both female and male adults of A. colemani were described using scanning electron microscopy (SEM). Generally, the filiform antennae of males ($l,515.2{\pm}116.5\;{\mu}m$) are longer than females ($l,275.1{\pm}103.4\;{\mu}m$). Antennae of this species are made up of radicle, scape, pedicel and flagellomeres. Male and female antennae differed in the total number of flagellomeres as 15 in males and 13 in females. The result of SEM observation was characterization and grouping of seven types of receptors into morphological classcs: Bohm bristles, Sensilla placodea, 2 types of S. coeloconica and S. trichodea, and S. basiconica as with a tip pore and with wall pores. In addition, the possible functions of the above sensilla types arc discussed in light of previously published literature; mechanoreception (Bohm bristles, S, coeloconica I & II and S. trichodea) and chemoreception (S. placodea, S. basiconica type I & II).

• Asian Journal of Turfgrass Science
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• v.18 no.4
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• pp.221-229
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• 2004

Biological control of lepidopterous insect pests, Agrotis segetum, Artogeia rapae, Mamestra brassicae, Plutella xylostella, Spodoptera exigua, and S. litura with entomopathogenic fungi, Beauveria bassiana and Metarhizium anisopliae isolated from Gyeongbuk province were investigated. Mean lethal concentration ($LC_50$) values of B. bassiana and M. anisopliae against $2\cdot3rd$ instar of A. segetum larvae were $1.2\times10^7\;conidia/m\ell$ and $5.2\times10^6\;conidia/m\ell$, respectively. $LC_50$ values of B. bassiana and M. anisopliae against $2\cdot3rd$ instar of A, rapae larvae were $1.2\times10^7\;conidia/m\ell$ and $5.2\times10^6\;conidia/m\ell$, respectively. $LC_50$ values of B. bassiana and M. anisopliae against $2\cdot3rd$ instar of M. brassicae and P. xylostella, larvae were $1.5\times10^6\;conidia/m\ell$, $9.7\times10^5\;conidia/m\ell$, $3.0\times10^6\;conidia/m\ell$ and $1.4\times10^6\;conidia/m\ell$, respectively. $LC_50$ values of B. bassiana and M. anisopliae against $2\cdot3rd$ instar of S. exigua, and S. litura larvae were $6.3\times10^6 \;conidia/m\ell$, $2.6\times10^6\;conidia/m\ell$, $1.6\times10^7\;conidia/m\ell$ and $3.4\times10^6\;conidia/m\ell$ respectively.

• The Korean Journal of Pesticide Science
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• v.10 no.4
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• pp.344-350
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• 2006

An Antiviral producing bacterial strain was isolated from ginseng root environment in Hongcheon, Kangwon province of Republic of Korea. Identification of this bacterial strain was performed by physiological and biochemical tests along with 16S rRNA analyses. The results revealed that the bacterium was closer to genus Serratia, which was named as Gsm01. The strain was grown in Mannitol-Glutamate-Yeast (MGY) broth for 48 h. The culture was centrifuged and the filtrate obtained was tested for its ability to control Cucumber mosaic virus strain Y (CMV-Y) in greenhouse and field experiments. In the green house experiments, CF was evaluated for its ability to protect local host, Chenopodium amaranticolor and systemic host of CMV, Nicotiana tabacum cv. Xanthi-nc. It was found that, CF treatment reduced viral infection by 98% in local host; C. amaranticolor. The N. tabacum cv. Xanthi-nc plants treated with CF did not show visible viral symptoms 15 days post inoculation (dpi) and remained symptomless throughout the periods of the study. To evaluate effectiveness of CF under field conditions, experiment was carried out in a polyvinyl house. It was observed that, 52% plants were protected from viral diseases compared to non-treated plants, increasing the crop yield. This is the first report showing antiviral activity of a Serratia spp. against CMV.