• Fisheries and Aquatic Sciences
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• v.12 no.1
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• pp.1-5
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• 2009

Crude saponin, extracted from the starfish Asterias amurensis, was assessed for its capacity as a biological pesticide. As part of this analysis, its insecticidal and repellent activities, in addition to its acute and chronic toxicities were tested. In comparison with the control group, insecticidal activity of saponin against tobacco cutworm, Spodoptera litura, in kale, Brassica loeracea was low at 36.4%. Repellent activities of the extracted saponin against green peach aphid, Myzus persicae, and S. litura, on soybean leaf, Glycine max and kale were 65.6% and 35.0% at $1^{st}$ day, and 54.5% and 30.0% at $3^{rd}$ day, respectively. Acute and chronic toxicity analysis was carried out using acute immobilizatioin test and reproduction impairment test, respectively. The saponin had 48 h-$EC_{50}$ of $65.21{\mu}g/mL$. Twenty-one day accumulative reproduction after treatment was lower in Daphnia magna at $7{\mu}g/mL$ saponin (78 youngs), compared with the control group (129 youngs). These results indicate that the extracted saponin exhibited some toxicity and has potential as a repellent against insects.

• Animal cells and systems
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• v.1 no.3
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• pp.475-482
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• 1997

The antiserum against locustatachykinin I, originally isolated from brain and retrocerebral complex of the locust Locusta migratoria, has been used to investigate changes in number, localization, and structure of locustatachykinin I-immunoreactive (LomTK I-IR) neurons in the brains of the common cutworm, Spodoptera Iitura, during postembryonic development. These neurons are found at larval, pupal, and adult stages. In the larval stages, the first instar larva shows the first appearance of about 8 LomTK I-IR neurons. These neurons gradually increase in number from the second to fourth instar larvae which have the largest number of about 92 in all postembryonic stages. Thereafter, these neurons decrease to about 28 in number in the 5-day-old pupa. However, they begin to rise again from the 7-day-old pupal stage, eventually reaching to about 90 in the l-day-old adult. The developing larval brains contain cell bodies of these neurons in most neuromeres. After the metamorphosis of larva to pupa and adult, localization of these neuronal cell bodies is confined to the specific cerebral neuromeres. The 7-day-old pupal brain shows the location of these neuronal cell bodies in pars intercerebralis, pars lateralis of protocerebrum, deutocerebrum, tritocerebrum, optic lobe-near region, and subesophageal ganglion. In the l-day-old adult, however, the brain has these cell bodies only in some neuromeres of protocerebrum, deutocerebrum, and subesophageal ganglion. Throughout the postembryonic life, changes in structure of these neurons coincide with changes in number and localization of these neurons. These findings suggest that changes in number, localization, and structure of these neurons reflect differentiation of these neurons to adult type.

• International Journal of Industrial Entomology and Biomaterials
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• v.10 no.1
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• pp.25-33
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• 2005

Recently a cDNA clone of apoLp-III from Hyphantria cunea was isolated and subjected to computational analysis to compare with other available sequences. Multiple sequence alignments were carried out using the amino acid sequences of apoLp-III from six insects. It was found that the H. cunea apoLp-III has relatively high sequence identities to Spodoptera litura ($69.5\%$), Manduca sexta ($66.8\%$), Galleria mellonella ($65.1\%$), Bombyx mori N4 ($54.3\%$) but less identity to Locusta migratoria ($18.3\%$). The amino acid composition was compared with other insects using EXPASY tools; it shows that alanine (Ala), glutamine (Gln), leucine (Leu) and lysine (Lys) are the major amino acid components of apoLp-III in H. cunea as well as other lepidopterans. Homology modeling performed using PSI-BLAST (PDB template M. sexta) reveals that the apoLp-III molecules consist of five, long amphipathic alpha helical bundles with short loops connecting the helices and shows homology with other insects. Phylogenetic analysis shows that the orthopteran apoLp-III represented by locust was most distantly related to the lepidopteran insects.

• 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.

• Korean journal of applied entomology
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• v.55 no.4
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• pp.445-452
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• 2016

Exorista japonica is one of the major natural enemies of noctuid larvae, Mythimna separata and Spodoptera litura. The examined parasitoid was obtained from host species M. separata, collected at Gimje city and identified by DNA sequences (partial cytochrome oxidase I, 16S, 18S, and 28S). For purposed of this study, laboratory reared S. litura served as the host species for the development of the E. japonica. The developmental period of E. japonica immature stages were investigated at seven constant temperatures (16, 19, 22, 25, 28, 31, $34{\pm}1^{\circ}C$, RH 20~30%). Temperature-dependent developmental rates and development completion models were developed. E. japonica was successfully developed from egg to adult in $16{\sim}31^{\circ}C$ temperature regimes. Developmental duration was the shortest at $34^{\circ}C$ (8.3 days) and the longest at $16^{\circ}C$ (23.4 days) from egg to pupa development. Pupal development duration was the shortest at $28^{\circ}C$ (7.3 days). Total immature-stage development duration decreased with increasing temperature, and was the shortest at $31^{\circ}C$ (16.3 days) and the longest at $16^{\circ}C$ (45.4 days). The lower developmental threshold was $7.8^{\circ}C$ and thermal constant required to complete total immature-stage development was 370.4 degree days. Among four non-linear temperature-dependent developmental rate models, Briere 1 model had the highest adjusted R-squared (0.96). The distribution model of development completion for total immature stage development of E. japonica was well described by all model ($r^2_{adj}=0.90$) based on the standardized development duration. These results of study would be necessary not only to develop population dynamics model but also to understand fundamental biology of E. japonica.

• Korean Journal of Environmental Biology
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• v.40 no.2
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• pp.187-198
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• 2022

In this study, Telenomus remus Nixon (Hymenoptera: Scelionidae) was first reported as a natural enemy of the fall armyworm Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) egg collected from corn fields in Korea, and its biological characteristics was studied. Based on morphological and molecular analysis, the parasitoid emerged from S. frugiperda eggs was identified as T. remus. We found that T. remus can attack the eggs of S. frugiperda, Spodoptera litra and Spodoptera exigua under a laboratory condition. The longevity of T. remus female adult was longer than that of male adult. The egg-to-adult period of T. remus was not affected by the host age and sex. T. remus female adult laid at least 1-3 eggs a day to a maximum of 37 or more eggs, and the most oviposited on the 3^rd to 4^th day after emergence. The host preference for oviposition of T. remus adult was high in the order of S. litura>S. exigua>S. frugiperda. T. remus preferred to parasitize 1- and 2-day-old host egg rather than 3-day-old host egg. When compared to the sex ratio of T. remus progeny, the rate of female progeny was higher at the initiation time of oviposition, while the proportion of male progeny increased significantly with female adult age, especially after 8-day-old adult. This information may be useful for improving T. remus mass rearing system and developing a biological control program to control S. frugiperda.

• Journal of Wetlands Research
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• v.20 no.2
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• pp.131-135
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• 2018

Plants produce extrafloral nectar (EFN), liquid of carbohydrates to protect themselves against various insect herbivores through attracting natural enemy, ants, wasp and parasitoids, so EFN production is well known as one of indirect defense mechanisms. In many plants, EFN production is increased or induced when plants are attacked and damaged by insect feeding, whereas there are some plants whose EFN production is not altered or even decreased upon insect attack. The feeding types (chewing or sap feeding) of insects attacking plants also affect EFN production. The objective of this study was to examine how insect herbivore alters production of extrafloral nectar of Impatiens balsamina. Two different types of herbivores, leaf chewing and sap feeding insects, Spodoptera litura and Impatientinum impatiens respectively, are utilized. Plants were mechanically damaged by making holes on leaves with Jasmonic acid (JA) and regurgitate of S. litura added on. Two different densities of aphids were confined on leaves. The results of the study was that mechanical damage and JA or regurgitate addition did not affect EFN production in I. balsamina. Aphid feeding, regardless of density treated, decreased EFN production. The results of the study suggest that production of extrafloral nectar of Impatiens balsamina can be changed by insect feeding, and the effects of insect feeding can depend on the type of insects.

• Korean journal of applied entomology
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• v.42 no.2
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• pp.145-152
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• 2003

Field application of the entomopathogenic nematode, Steinernema carpncapsae, is limited by its susceptibility to UV irradiation and desiccation especially at leaf spray control. This study was conducted to develop the control technique using alginate biocapsulation of the nematodes against the beet armyworm, Spodoprera exigua and the tobacco cutworm, Sp. litura that are normally infesting hosts above ground level. The alginate capsules including infective juveniles gave significant feeding toxicities to the larvae of the two lepidopteran species. The lethality followed a typical sigmoid dose-mortality pattern with increase of the nematode densities embedded in the capsules. Moisture content in the capsule was critical to the survival of the infective juveniles. More than 80% nematodes could survive above 10% moisture content remained in the capsule. Remaining moisture content within the capsule was dependent on relative humidity, ambient temperature, and capsule size, but not on citric acid reaction time during capsule formation. More than 80% of infective juveniles in the alginate capsules could survive in distilled water at 15$^{\circ}C$ for 60 days. When these nematode capsules containing welsh onion extract as another phagostimulant were applied on the 3rd instar larvae of Sp. exigua infesting peanut plants, they resulted in about 90% control efficacy. These results indicate that the alginate capsulation can be used for leaf-spray agent of the entomopathogenic nematodes as well as for improved storage purpose.

• Asian Journal of Turfgrass Science
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• v.25 no.1
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• pp.30-42
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• 2011

Moths were collected to survey turfgrass pest and to compare species diversity from Jinju Country Club in Jinju, Gyeongsangnamdo, Korea, every 10 days using 200W mercury light trap from middle May to late October in 2008. As the results, only 23 individuals of Pseudaletia separata, Spodoptera depravata, Spodoptera litura, Agrotis segetum, and Agrotis ipsilon were collected as turf grass insect pests. However, 2028 individuals of 388 species in 22 families were collected in total. Dominant species was Culcula panterinaria, Fentonia ocypete, Hypsopygia regina, Culcula panterinaria, Flavocrambus striatellus, and Diarsia camescens in May, June, July, August, September and October, respectively. Species diversity was not different between two surveyed sites, but different among surveyed time. Species richness was more higher in hole 11 (Hole was surrounded by natural forest and located near pond) than hole 15 (Hole was located at the top part of mountain). Dominance index of moth was increased from October compared with diverse index and richness index were decreased from October. A large number of species and individuals were recorded in Noctuidae (502 individuals in 131 species), Geometridae (491 individuals in 84 species), Pyralidae (386 individuals in 73 species), and Notodontidae (277 individuals in 25 species). These four families were 80.9% out of all the collected species.

• Korean Journal of Organic Agriculture
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• v.25 no.2
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• pp.419-429
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• 2017

We investigated the occurrence pattern of diseases and insect pests and disease control efficacy of organic materials against watermelon powdery mildew in small type watermelon in Eumseong, Chungcheongbuk-do, 2015. The result of this study, the small type watermelon was damaged by diseases and pests such as Didymella bryoniae, Podosphaera xanthii, Aphis gossypii, Tetranychus urticae, thrips, Spodoptera exigua and Spodoptera litura. Among them, the occurrence of P. xanthii, T. urticae and thrips was high. Diseased leaf rate by P. xanthii, a casual agent of powdery mildew, was 27~99.3% in three small type watermelon cultivars in the middle of June. The number of T. urticae per leaf was high from 79.9 to 111 in three small type watermelon cultivars in the middle of June. It showed high number of thrips captured by yellow and blue sticky trap. Highest numbers of yellow sticky trap (407) and of blue sticky trap (774) were detected in the middle and first of June, respectively. The disease control efficacy of mayonnaise, oleic acid and three organic materials against powdery mildew of small type watermelon in fields was evaluated. As thre results, the symptoms of plant disease were effectively reduced by over 60% in the treatments of materials such as sodium bicarbonate 80%, mayonnaise and the extract of Rheum palmatum 1%. The highest control efficacy was 83% in the treatment of sodium bicarbonate 80%. From this study, we had a information of the occurrence pattern of diseases and insect pests in small type watermelon and the treatment of material containing sodium bicarbonate 80% was very effective for controlling against powdery mildew.