• Korean journal of applied entomology
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• v.43 no.2
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• pp.175-180
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• 2004

This study was conducted to determine the effect of sublethal concentrations ($LC_{10}$ and $LC_{30}$) of insecticides on pupal duration, emergence, adult longevity and oviposition of tobacco cutworm, Spodoptera litura Fabricius, when 3rd instar larva of tobacco cutworm was treated with insecticides of chlorpyrifos, ethofenprox, chlorfenapyr-bifenthrin and hexaflumuron-chlorpyrifos . Pupal duration of female and male were 6.9 days and 8.0 days at untreatment, and were 7.2 to 7.6 days and 8.3 to 8.6 days at insecticide treatment, respectively. Thus pupal duration at the insecticide treatment was slightly longer than that at the untreatment, and that of the males was slightly longer than that of the females even though significant difference between sublethal concentrations and among insecticides was not observed. Percent mergence was 88％ at untreatment and ranged from 79％ to 95％, in particular which showed above 91％ treated with chlorfenapyr-bifenthrin and ethofenprox, at insecticide treatment. Adult longevity was 7.7 days and 7.9 days for female and male at untreatment respectively, and 7.1 to 8.4 days for female and 7.7 days to 9.0 days for male at treatment. There was a significant difference between insecticides and sublethal concentrations of insecticides except showed the longest adult longevity at hexaflumuron-chlolfyrifos treatment. Total number of eggs laid were less at treatment (778-948) than that (1,010) at untreatment regardless of sublethal concentrations of insecticides. Accordingly the pupal duration and oviposition of tobacco cutworm were affected at the insecticide treatment of sublethal concentration.

• Journal of Plant Biotechnology
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• v.35 no.2
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• pp.147-153
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• 2008

Cry1Ac gene was introduced into chrysanthemum (Dendranthema grandiflorum Kitamura) 'Linneker Salmon' through Agrobacterium-mediated gene transformation to develop new lines showing resistance to tobacco cutworm (Spodoptera litura). Cry1Ac gene was transferred into chrysanthemum by Agrobacterium C58C1 containing pCAMBIA2301. After infection of Agrobacterium C58C1 with leaf segments, the segments were cultured on regeneration medium (MS + 1.0 mg/L BA + 0.5 mg/L IAA) containing 10 mg/L kanamycin for the first selection, on the same medium containing 20 mg/L kanamycin for the second selection, and on rooting medium (MS basal medium) containing 20 mg/L kanamycin for the third selection. Until the third selection, sixty nine plantlets (1.6%) were survived and rooted. Thirty six ones (0.8%) among them were confirmed as putative transformants with nptll gene by nptll primer PCR, and 35 (0.8%) of 36 ones as transformants with nptll gene and cry1Ac gene by Southern analysis. The gene transformation efficiency of cry1Ac gene was favorable with 0.8%. The resistance of tobacco cutworm (Spodoptera litura) in chrysan-themum transformant introduced cry1Ac gene was tested in green house. Three transformants were confirmed to have resistance to tobacco cutworm.

• Korean journal of applied entomology
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• v.49 no.4
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• pp.351-355
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• 2010

This study was conducted to determine the relationship of larval density of tobacco cutworm, Spodoptera litura (Fabricius) to damage in greenhouse sweet pepper. Laboratory experiments, cage experiments by artificial release and field investigation were carried out in 2008. The leaf consumption rate increased greatly with larval development. The damaged leaves had several round or oval shape holes on the surface or lost certain parts of them, and the fruit damaged had a conspicuous hole on the surface or scar marks around the calyx. In the field investigation, fruit damage was highly correlated with larval densities and reached 3.5% damage at maximum. Cage experiments showed that numbers of non-marketable fruit increased as increasing larval densities released. The larval density at two weeks before harvest had a high relationship with the percentage of damaged-fruit at harvest. Corresponding larval density caused 1, 3, 5% of damaged-fruit was 0.2, 0.5, 0.8 larvae per plant, respectively.

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2004.05a
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• pp.169-169
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• 2004

• Korean journal of applied entomology
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• v.38 no.3
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• pp.225-230
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• 1999

This study was conducted to determine the effect of pupal development and adult longevity of Spodoptera litura larvae reared on leaves of different leguminos plants of 11 varieties or cultivars. Pupal duration varied from 8.7 to 9.5 days depending upon different diets and duration of female pupa (8.3~9.1 days) was about 1 day shorter than that of male's (9.4~10.1 days). Prepupal an postpupal duration were 1.7 to 2.0 days and 6.7 to 7.7 days, respectively. Pupal weight ranged from 0.23g to 0.43g for female and 0.24g to 0.35 g for male. Percent change of pupal weight was lowest (11%) on geomjeongkong-1 and highest (16%) on bukwangkong. Adult longevity was in ranging from 7.8 days on dongbu to 11.2 days on bukwangkong and tended to become slightly longer in female than tin male. Significant relationships were recognized between moisture content of feeding leaf, the pupal duration and weight and adult longevity.

• Korean journal of applied entomology
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• v.31 no.4
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• pp.452-460
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• 1992

To establish the economical and reliable routine bioassay system for developing new insecticidal compounds, effects of leaf-dipping time, application methods, insect species and their developmental stages on susceptibilities of insects to insecticides were studied. The stable insecticidal activity appeared at the dipping time for 30-60 seconds in leaf-dipping method, and the most effective application methods were leaf-dipping method for apterous green peach aphid adults, and third instars of diamond-back moth and tobacco cutworm, whereas seedling+insect spray method for adults or third instars of brown planthoppers. For two-spotted spider mite, leaf-dipping or intact plant spray method was favorable. In the bioassay for chitin synthesis inhibitors, the inoculation of third instars of brown planthopper, diamond-back moth, tobacco cutworm and green peach aphid, and larvae of two-spotted spider mite to the young host plants treated by spray method were adequate bioassay methods.

• Korean journal of applied entomology
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• v.30 no.1
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• pp.18-28
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• 1991

The optimal pH of the extraction buffer was 7.5 considiering AChE stability and its buffer capacity when AChE was isolated and extracted from the housefly(Musca domesitca L.)and three other insect species with 0.01 M sodium phosphate buffer. Also, the optimal pH of the reaction buffer was 7.5 considering enzyme activity and its buffer capacity when AChE activity was measured with the substrate in 0.1 M sodium phosphate buffer. The Potter Elvehjem type homogenizer with Teflon pestle was used to homgenize the tissues. When preparing a AChE suspension by centrifuging the homogenate, 700 g supernatant of adult head for the housefly, 700 g supernatnat of 5th instar nymphal whole body for the brown planthopper, lipid-eliminated 10,000 g supernatant of 5th instar larval whole body for the diamondback moth, and 700 g supernatant of 4th instar larval head for the tobacco cutworm were considered satisfactory as enzyme sources in view of mass preparation, extraction efficiency and stability of enzyme activity during evaluation. When AChE suspensions of 4 insect species were stored at $-18^{\circ}C$, more than 90% of activity was maintained up to 3 weeks. Km values of AChEs of the housefly, the brown planthopper, and the diamondback moth were 0.042, 0.037 and 0.043 mM, respectively and AChE-specific substrate inhibition was observed at high concentration. Km value of the tobacco cutworm ChE was 1.15 mM and BuChE characteristics was observed, though further study is needed. The optimal substrate concentration for the AChE inhibition tests was 0.5 mM for the housfly, the brown planthopper, and the diamondback moth and 12 mM for the tobacco cutworm.

• 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.36 no.1
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• pp.48-54
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• 1997

This study was conducted to determine the effect of temperatures and food sources on the egg and larval developmentof the tobacco cutworm, Spodoptera litura Fabricius. The hatchability of egg masses of S. liturawas 100% on the leaf of soybean, perilla and sweet potato in any given temperature regimes, while the hatchabilitywas only 65-8796 when reared on the pulp paper and decreased as temperature increased. Egg durationwas not significantly different among different food sources within each temperature. However, egg duration at32$^{\circ}$C was shorter than that at 24$^{\circ}$C and 28$^{\circ}$C. During the early larval development, at 28$^{\circ}$C and 32$^{\circ}$C the larvafed on sweet potato leaf was heavier than those fed on soybean and perilla leaves and the opposite case wastrue during mid-larval development stage. However, larval weight at 24$^{\circ}$C was heavier on sweet potato leafthan that on soybean and perilla leaves until 12 days after hatching. This result was probably due to relativelyslower developmental rate at 24$^{\circ}$C compared to 28$^{\circ}$C and 32$^{\circ}$C. The mean larval mortality was 68.896, 44.5%and 33.8% at 24$^{\circ}$C. 28$^{\circ}$C and 32"C, respectively. The lowest mortality was observed on soybena leaf and followedby perilla and sweet potato leaves, and artificial diet regardless of temperature conditions. The durationwas the shortest when they fed on soybean leaf, and followed by perilla and sweet potato leaves and artificialdiet. Larval durations were 23.6-30.4 days at 24$^{\circ}$C. 18.6-22.3 days at 28$^{\circ}$C and 14.5-18.0 days at 32$^{\circ}$C. Thethreshold temperatures of egg and larva of S. litura were about 6.l"C and 10.9"C, respectively.t 6.l"C and 10.9"C, respectively.pectively.

• Korean journal of applied entomology
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• v.38 no.1
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• pp.23-28
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• 1999

This study was conducted to determine the effect of temperatures, 24"C, 28$^{\circ}$C and 32"C,and food sources on pupal development, adult longevity and oviposition of tobacco cutworm, Spodopteralitura Fabricius. Percent pupation of S. litura was became higher at higher temperature from 23% to 88%.And its percent pupation was highest on soybean leaf (SL), followed by perilla leaf (PL), sweet potato leaf(SPL) and artificial diet (AD). Pupal weight ranged from 0.28g on SPL to 0.40 g on PL and was tended toheavier with decreasing temperature. The mean pupal duration was 14, 10 and 7 days at 24"C, 28$^{\circ}$C and32"C, respectively. Percent emergence was in range of 21% to 89% with higher percent emergence as thetemperature increased and both 28$^{\circ}$C and 24$^{\circ}$C was highest on SL, followed by PL, SPL and AD, but at24$^{\circ}$C the order was SPL, PL, SL and then AD. Preoviposition duration was 3.2 days at 24"C, 2.8 days at28$^{\circ}$C and 2.5 days at 32$^{\circ}$C. Adult longevity became shorter as the temperature increased from 6.4 to 3.9days. Male longevity was longer than that of female. Adults lived longest when they were reared on PL,followed by SL, SPL and AD. Total number of eggs laid per female varied from 803 to 1,441 regardlessof the treatments, but those were significantly more on natural foods than on AD. Number of eggs per eggmass was 97.4 at 24$^{\circ}$C 155.8 at 28$^{\circ}$C and 104.7 at 32$^{\circ}$C. Number of egg mass was 12.0, 6.7 and 11.3 at24"C, 28$^{\circ}$C and 32"C, respectively.4"C, 28$^{\circ}$C and 32"C, respectively.