• Korean journal of applied entomology
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• v.47 no.2
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• pp.175-184
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• 2008

To screen highly active Bacillus thuringiensis isolates against Spodoptera litura (Lepidoptera, Noctuidae), 46 B. thuringiensis was isolated from 115 samples obtained from several crop soils. Especially, B. thuringiensis subsp. kurstaki CAB133 and CAB162 isolates showed 100% mortality against S. litura. $LD_{50}$ values of CAB 133, CAB162 and HD-1 strains of B. thuringiensis subsp. kurstaki were 0.089, 3.144 and $0.513{\mu}g/ml$ against 2nd larva of S. litura, respectively. The weight of 3rd larva of S. litura which were fed crystal inclusion protein $(1.267{\mu}g/ml)$ with B. thuringiensis subsp. kurstaki CAB133 was about 30 times lass than control group. CAB133 and CAB 162 strains of B. thuringiensis subsp. kurstaki which were taken a highly toxity against S. litura were analyzed by SDS-PAGE, and estimated the molecular weight of the Cry proteins. Their serological identification by H serotypes were showed B. thuringiensis subsp. kurstaki (3abc) type.

• Journal of Plant Biotechnology
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• v.6 no.3
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• pp.145-150
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• 2004

Cabbage plants were transformed with the potato proteinase inhibitor II (PINII) gene, bar gene, and hpt gene using Agrobacterium. The expression of the PINII gene was driven by its own promoter which was wound-inducible. Ten transgenic plants were obtained from medium containing hygromycin as a selection antibiotic. The integration and expression of PINII and bar genes were confirmed by Southern and Northern hybridization. Growth and development of diamondback moths (Plutella xylostella) and tobacco cutworm (Spodoptera litura) larvae were examined on $T_1$ plants. The weight of the larvae and pupae of these two insects grown on transgenic plants was not different compared to those grown on wild type plants. However, the pupation and emergence rate of diamondback moths and tobacco cutworms fed on some transgenic plants was lower than on wild type plants. These results suggest that the PINII transgene under the control of a wound-induced promoter may be used for control of insects in transgenic cabbage through reduction of insect progeny number.

• Korean journal of applied entomology
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• v.30 no.2
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• pp.144-149
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• 1991

Biochemical characteristics of Spodoptera uigua nuclear polyhedrosis virus (SeNPV) isolated in Jinju were studied. SeNPV contained a number of nucleocapsids within a viral envelope embeded in polyhedra. The polyhedral protein of SeNPV was composed of a single polypeptide with a M. W. of 30kd. Double-immunodiffusion test showed that the polyhedral protein of SeNPV had common antigenic determinants with SINPV and BmNPV. Virion proteins of SeNPV were resolved into 49 polypeptides by silver staining after SDS-PAGE. The approximate genome size of SeNPV by restriction endonuclease analysis was 1l0kb.

• The Korean Journal of Pesticide Science
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• v.14 no.4
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• pp.446-455
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• 2010

The characteristics of parasporal inclusion body from Bacillus thuringiensis subsp. kurstaki KB099 isolate which is high bioactive to the tobacco cutworm, Spodoptera litura, were examined. Parasporal inclusion of B. thuringiensis subsp. kurstaki KB099 isolate showed only 1 band at 130 kDa compared with B. thuringiensis subsp. kurstaki HD-l isolate producing 2 protein bands at 130 kDa and 60 kDa from by SDS-PAGE analysis without any enzyme treatment. Also, we confirmed that gut extract of sensitive S. litura KB099 isolate had digested only 60 kDa ${\delta}$-endotoxin protein. When the digestive enzyme of sensitive insect responsible for parasporal inclusion from KB099 and HD-l isolate was treated to each of them, protein band 60 KDa of KB099 was maintained up to 12 hours but all bands of HD-l were disappeared within 6 hours. In KB099 isolate, 6 genes (Cry1Aa, Cry1Ab, Cry1Ac, Cry1C, Cry1D and Cry1I) were identified by PCR analysis. Also, $Cry^-$ mutant of KB099 isolate was investigated by phase- contrast microscope, SDS-PAGE and PCR.

• Korean journal of applied entomology
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• v.45 no.3 s.144
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• pp.357-362
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• 2006

Bacillus thuringiensis strains were isolated from the domestic soil and a strain was selected that had a new host range and high toxicity against agriculture insect pest. The 142 samples of soil were sampled from the mountains, paddy fields and patches, in Daejon, Chungnam, Chungbuk and Jeonbuk and used for the investigation. Sixteen B. t strains were isolated from 12 samples among collected samples. There were 11 strains that showed toxical activity on Plutella xylostella (Lepidoptera: Yponomeutidae), 7 steins on Spodoptera litura (Lepidoptera: Noctuidae), 5 strains on Arete coerulea (Lepidoptera: Noctuidae), 5 strains on Culex pipiens pallens (Diptera: Culicidae) among the 16 isolated B. t strains. But there were not any strains that showed activity against Hyphanria cunea (Lepidoptera: Arctiidae) and Sitophilus oryzae (Coleoptera: Rhynchophoridae). And also some of B. thuringiensis strains showed insecticidal activity with 2, 3 or 4 kinds of insects. But there were also 3 strains that did not show any activities to the 6 insects which were used in the experiment. When examined with a phase-contrast microscope, the insecticidal crystal protein produced from 16 selected strains had 13 bipyramidal and 3 spherical shapes. The insecticidal bioactivity of the S. litura showed 100% mortality when there were $1.3{\times}10^{7}\;(cfu/ml)$ of CAB109 isolates.

• Korean journal of applied entomology
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• v.48 no.4
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• pp.509-517
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• 2009

Bacillus thuringiensis subsp. aizawai CAB109 isolated in Korea is known active against Spodoptera sp.. Especially, B. thuringiensis aizawai CAB109 isolates showed 100% mortality against Spodoptera litura and Spodoptera exigua. To screen highly active B. thuringiensis, the pathogenicity of B. thuringiensis CAB109 was compared with that of commercialized B. thuringiensis products. $LC_{50}$ values of CAB109, product TB-WP and product SC strains of B. thuringiensis were $1.3{\times}10^5$, $2.3{\times}10^6$ and $5.2{\times}10^5\;cfu/ml$ against the 2nd larva of S. litura and $1.8{\times}10^4$, $1.3{\times}10^6$ and $1.5{\times}10^6\;cfu/ml$ against the 2nd larva S. exigua, respectively. To determine new gene's existence and absence, the plasmid DNA was extracted, and compared to that of B.t. aizawai HD-133. Both B. thuringiensis were not like plasmid DNA pattern. PCR technique was used to predict both plasmid DNA's cry gene. PCR products analysis showed that B.t. CAB109 harbor Cry1Aa, Cry1Ab, Cry1C and Cry1D and B.t. HD-133 has Cry1Aa and Cry1Ab, respectively.

• Korean journal of applied entomology
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• v.53 no.3
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• pp.231-237
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• 2014

This study was carried out to investigate the pest species and their damage on Asparagus officinalis. Field surveys were conducted in asparagus greenhouse in Jeju, for four years from 2007 to 2010. Total of 16 pest species belonging to 5 orders were found as follows: Thrips tabaci, Thrips hawaiiensis, Adoxophyes honmai, Spodoptera litura, Spodoptera exigua, Helicoverpa armigera, Mamestra brassicae, Ascotis selenaria, Ectropis excellens, Geisha distinctissima, Aphis gossypii, Myzus persicae, Anomala albopilosa, Crioceris quatuordecimpunctata, Acusta despecta sieboldiana and Deroceras reticulatum. Among them, T. tabaci frequently occurred and damaged asparagus plants during the whole growing seasons. C. quatuordecimpunctata and snails caused severe damages on asparagus shoots in spring harvest season. In mid-late seasons, aphids and lepidopteran species occurred and attacked asparagus plants. Of the lepidopteran pests, S. litura, S exigua and H. armigera belonging to Noctuidae occurred moderately and fed on asparagus plants. And the pest control strategy in asparagus cultivation was discussed based on the present results.

• Mycobiology
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• v.43 no.2
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• pp.137-149
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• 2015

In the search for novel potent fungi-derived bioactive compounds for bioinsecticide applications, crude ethyl acetate culture filtrate extracts from 110 mangrove fungal endophytes were screened for their toxicity. Toxicity tests of all extracts against brine shrimp (Artemia salina) larvae were performed. The extracts with the highest toxicity were further examined for insecticidal activity against Spodoptera litura larvae and acetylcholinesterase (AChE) inhibition activity. The results showed that the extracts of five isolates exhibited the highest toxicity to brine shrimp at 50% lethal concentration ($LC_{50}$) values of 7.45 to 10.24 ppm. These five fungal isolates that obtained from Rhizophora mucronata were identified based on sequence data analysis of the internal transcribed spacer region of rDNA as Aspergillus oryzae (strain BPPTCC 6036), Emericella nidulans (strains BPPTCC 6035 and BPPTCC 6038), A. tamarii (strain BPPTCC 6037), and A. versicolor (strain BPPTCC 6039). The mean percentage of S. litura larval mortality following topical application of the five extracts ranged from 16.7% to 43.3%. In the AChE inhibition assay, the inhibition rates of the five extracts ranged from 40.7% to 48.9%, while eserine (positive control) had an inhibition rate of 96.8%, at a concentration of 100 ppm. The extracts used were crude extracts, so their potential as sources of AChE inhibition compounds makes them likely candidates as neurotoxins. The high-performance liquid chromatography profiles of the five extracts differed, indicating variations in their chemical constituents. This study highlights the potential of culture filtrate ethyl acetate extracts of mangrove fungal endophytes as a source of new potential bioactive compounds for bioinsecticide applications.

• Korean journal of applied entomology
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• v.38 no.3
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• pp.217-224
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• 1999

This study was conducted to determine the larval development of tobacco cutworm, Spdodoptera litura Fabricius, reared on leaves of different leguminous plants of 11 varieties or cultivars, and to measure amount of leaves fed by the larva. Larval duration ranged from 11.5 to 15.7 days depending on different food with the shortest on geomjeongkong-1 and the longest on daek-wangddangkong. Among 6 larval development stages, the 1st instar stages was the longest(3.2~5.0 days) while the 4th instar was the shortest (1.0~1.5 days). In general, amount of leaves consumed was increased with larval age, and consumed from 5 to 74% of total food only during the last instar stage. And female consumed more food than male. While, larval mortality and the sex-ratio seem to have no relation with the amount of food per species.

• Korean journal of applied entomology
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• v.40 no.2
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• pp.137-141
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• 2001

This experiment was conducted to investigate the control effect of nuclear polyhedrosis virus and NeemAzal-T/S on Spodoptera litura larvae. In laboratory test, values of$ LT_{50}$ and $LT_{95}$ when treated with S. litura nuclear polyhedrosis virus (SINPV) $1$\times$10^{8}$ PIBs/ml plus NeemAzal-T/S 200 ppm were 1.94 and 8.33 days, respectively. Control effect of the combination of SINPV $1$\times$10^{8}$ plus NeemAzal-T/S 200 ppm was higher than the other concentrations. This mixed treatment could reduce LT$_{95}$ by 3 days. When SINPV alone was sprayed to the S. litura larvae reared on chinese cabbage seedling, the mortalities were 10.7~6.7% at 4 days after treatment. In combinations of SINPV plus NeemAzal-T/S at each level of concentration, the mortalities appeared faster and higher at 4 days after application than single treatment. Especially, the mortalities by combinations of SINPV $1$\times$10^{8}$ /PIBs/ml plus NeemAzal-T/S at 75~200 ppm were 100% at 9 days after treatment. The body weight of untreated larvae was increased 9.4-folds from 235 mg to 2194 mg after 7 days. However, the increasing levels of larval weight were 4.8- and 7.0-folds in the separate treatments of NeemAzal-T/S and SINPV, respectively. Whereas in the combinations of SINPV $10^{4~8}$ PIBs/ml plus NeemAzal-T/S 75~200 ppm, larval weight was increased 3.9 to 2.9-folds. These results showed that the mortality and inhibition of larval weight in the combination of SINPV and NeemAzal-T/S were highly enforced by synergistic effect.