• Korean journal of applied entomology
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• v.60 no.4
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• pp.473-477
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• 2021

An artificial diet containing wheat germ, soybean, corn, yeast, sucrose, casein, cholesterol, 𝛽-sitosterol, and dry Miscanthus sacchariflorus stem powder was developed for rearing Chilo suppressalis (Crambidae) larvae. Neonate larvae were individually raised on the diet till adult emergence at 25℃ and 15:9 h light:dark photoperiod. In the results, the pupation and the emergence rates were 82.2% and 98.6%, respectively. The mean developmental periods of female and male larvae were 34.6 days and 31.0 days, respectively, whereas the pupal periods of female and male were 8.9 days and 9.7 days, respectively. Those periods were significantly different between genders. The mean pupal weights of female and male were 75.0 mg and 57.0 mg, respectively, with significant difference.

• Korean journal of applied entomology
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• v.58 no.2
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• pp.101-109
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• 2019

An entomopathogenic bacterium, Xenorhabdus ehlersii KSY, is symbiotic to a nematode, Steinernema longicaudum, and exhibits high entomopathogenic virulence against lepidopteran insects. This study showed that the bacterial pathogenicity is induced by its inhibitory activity against eicosanoid biosynthesis of target insects, resulting in immunosuppression. To be applied for insect pest control, the bacteria should be infected to insect hemocoel. To deliver X. ehlersii to inset hemocoel, Bacillus thuringiensis (Bt) was mixed with the bacteria to breakdown the physical barrier (= midgut epithelium) from midgut lumen to hemocoel. The bacterial mixture significantly enhanced insecticidal activity of Bt only against larvae of Plutella xylostella and Maruca vitrata. For formulation, X. ehlersii cells were freeze-dried and mixed with sporulated Bt cells. The formulated bacterial mixture was applied to semi-field cultivating cabbage crop infested by P. xylostella. The bacterial mixture treatment showed over 95% control efficacy, while Bt alone gave 80% control efficacy. These results suggest that X. ehlersii can be applied to develop a novel insect control agent.

• Korean journal of applied entomology
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• v.61 no.1
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• pp.51-62
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• 2022

Numerous insect pests threaten the Korean orchard industry through feeding on various tissues of fruit trees. Generally, the control of economically important orchard pests is based on the use of chemical insecticides. Owing to growing concerns regarding the environmental and human health effects of insecticides, environment-friendly pest control strategies are urgently needed. Pheromones of orchard pests could lead to an environmentally safe control system based on mating disruption or mass trapping. This review summarizes the functions and compounds of known pheromones from 51 orchard pests in Korea. The pheromones identified to date from 14 species in the families Miridae, Aphididae, Diaspididae, Pseudococcidae, Rutelidae, Cecidomyiidae, and Eurytomidae and 26 species in the order Lepidoptera are female-produced sex pheromones that attract only males. In contrast, all known examples for 11 species in the families Alydidae, Pentatomidae, Thripidae and Cerambycidae are male-produced aggregation pheromones that attract both sexes. Research on pheromones in new pests, kairomones in key orchard pests, mating disruption dispensers to generate prolonged release of the pheromones, and trap design and trap location for mass trapping will be required for the expanded use of pheromones and other semiochemicals in orchard pest management in the future.

• 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.

• Korean journal of applied entomology
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• v.47 no.1
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• pp.23-29
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• 2008

The biology of indian meal moth and maize weevil on the trehalose gene introduced rice (var 'Nakdong') (T-Nakdong) was compared to that on the rice without gene introduction (Nakdong) at $28{\pm}1.0^{\circ}C$. Development of the both two insects was significantly delayed; on T-Nakdong, the developmental periods of female moth $({\pm}SE)$ and weevil were $38.46{\pm}0.42\;and\;36.38{\pm}0.28days$, respectively. Whereas those on Nakdong were $36.38{\pm}0.28\;and\;34.33{\pm}0.18$, respectively. Net reproduction rate of Indian meal moth on T-Nakdong $(3.0{\pm}0.14)$ was significantly lower than that on Nakdong $(9.25{\pm}0.13)$, due to the lower emergence rate $(21.08{\pm}0.04%\;vs\;48.30{\pm}0.06%)$. The life table statistics of maize weevil on T-Nakdong was estimated to be similar to those on Nakdong. The delayed development of T-Nakdong suggested that the factor for development of the insects could be changed by the introduction of trehalose gene into the rice variety.

• Journal of the Korean Society of Safety
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• v.12 no.4
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• pp.214-219
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• 1997

The mechanical seals, which are installed in rotating machines like pump and compressor, are generally used as sealing devices in the many fields of industries. The failure of mechanical seals such as leakage, crack, breakage, fast and severe wear, excessive torque, and squeaking results in big problems. To identify abnormal phenomena on mechanical seals and to propose the proper monitoring parameter for the failure of mechanical seals, sliding wear experiments were conducted. Acoustic emission, torque, and temperature were measured during experiments. Optical microstructure was observed for the wear processing after every 10 minute sliding at rotation speed of 1750 rpm and scanning electron microscopy was also observed. Except for the initial part of every experiment, the variation of acoustic emission was well coincided with torque variation during the experiments. This study concludes that acoustic emission and torque are proper monitoring parameters for the failure of mechanical seals. The intensity of acoustic emission signals is measured in root mean square voltage. Temperature of sealing face will be used as a parallel parameter for increasing the reliability of monitoring system.

• The Korean Journal of Malacology
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• v.29 no.3
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• pp.171-179
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• 2013

Arginine kinase (ArK) is known to play an important role in most invertebrates the level of ATP by phosphorylation of phosphagens in cell and immuninty in living organisms. ArK has been identified in many kinds of organisms ranging from invertebrate to vertebrate. However, no ArK gene has been cloned and investigated from N. samarangae. This leads us to identify ArK cDNA (NsArK) from the expressed sequence tag (EST) sequencing of N. samarangae. Sequence analysis indicated that the coding region of 1,065 bp contains 355 amino acid residues. Molecular phylogenetic analysis shows that NsArK had very high similarities with mollusca and arthropoda. In an attempt to investigate a potential role of NsArK in the digestive gland of N. samarangae, expression patterns were analyzed. RT-PCR analsysis shows that NsArK mRNA is induced in the rane of 1.2 fold at 6 hr by laminarin when compared with the control. The immunnologial and physiological role of NsArK remains to be further investigated in N. samarangae.

• Korean journal of applied entomology
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• v.61 no.4
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• pp.641-649
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• 2022

Leaf-rolling moths were collected from soybean fields and identified as Matsumuraeses falcana and Matsumuraeses phaseoli by comparison with laboratory-reared species based on the nucleotide sequence (658 bp) of the mitochondrial cytochrome c oxidase 1 subunit gene (COX1). Ten haplotypes with 0.15-0.46% genetic distance from each other in COX1 were found in 47 samples of M. falcana, in which haplotype A was dominant (approximately 70%). Only one type of COX1 was found in 30 samples of M. phaseoli, and its sequence showed 4.11-4.61% genetic distance from those of M. falcana. Amino acid sequences translated from COX1 were identical in all samples of both species, and they showed synonymous substitutions. Larvae of both species caused damage to soybean leaves and pods and co-occurred simultaneously in the field. The average density of M. falcana was 1.5 times higher than that of M. phaseoli. The results clearly indicate that soybean was the host plant for both species. In addition, Elodia flavipalpis (Diptera: Tachinidae) was found to be a larval parasitoid of Matsumuraeses sp. through identification of the COX1 gene.

• Korean journal of applied entomology
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• v.24 no.1 s.62
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• pp.45-50
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• 1985

The use of a modified procedure for the isolation of extrachromosomal DNA of low to high molecular weight, followed by agarose gel electrophoresis of the crude lysates, provided a simple screening procedure for detecting plasmids ranging in molecular weights from approximately 1 to more than 135 megadaltons from serovars of Bacillus thuringiensis. The procedure provides for a relatively large-volume stable lysate for isolation of plasmids for restriction endonuclease mapping and cloning procedures. The method was used for screening of plasm ids in 6 differenentially effective serovars of B. thuringiensis toxic to dipteran and lepidopteran insects. Relatively large plasmid DNAs of masses above 50 megadaltons (Mdal) were isolated from all of the serovars examined using this technique. The number of extrachromosomal DNAs detected in serovars of B. thuringiensis was 8 for israelensis, 10 for kurstaki, 13 for aizawai, 2 for dendrolimus, 1 for finitimus, and 6 for yunnanensis. Smaller plasmid DNAs were isolated in four of the six serovars that ranged in mass down to approximately 2 Mdal.

• Korean journal of applied entomology
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• v.27 no.2
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• pp.117-124
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• 1988

An Investigation of insect pests in rice stored was carried out in Jeonnam region of Korea. The total of 2 class, 7 orders 16 families and 25 species were recorded in Lepidoptera; 8, Coleoptera; 11, Orthoptera; 1, Thysanura 1, blattaria; 2, Hymenoptera; 1 and mites; 2 spe-cies. The important species among them were Sitotroga cerealella, Ephestia cautella, Paral-ipsa gularis, Poldia, in Lepidoptera, and Sitophilus orzae, Oryzaephilus surianmensis, Cryptolestes ferrugineus, Tribolium castaneum, Tenebroides mauritanicus, Attagenus japonicus, in Coleoptera and Blatella germanica, in Blattaria and Acarus siro Petrobia latens, in mites. The duration of maximum occurrence were the late June to mid July for Sitotroga cerealella, the mod July to early August for Oryzaephilus surianmensis the mid July to August for Tribolium castaneum, the early July to late July for Sitophilus orzae, the mid June to early July for Attagenus japonicus the mid June to late Spetember for Blatella germanica and the late April to late May for Acarus siro and Petrobia latens, respectively in investigation, Blatella germanica(Blattaria) which was no problem in stored rice insect till now was mainly distributed a coastal plain and period of occurrence was long amount of occurrence was great. Rice weevil has 4 generations under natural conditions and the peak of 1st perood time was ranged from middle of jun. to last decade of Jun., 2nd period was from the lats decade of Jul. to first decade of Aug., 3rd period was from middle of Sep. to late Sep., 4th period was middle of Oct. to early Nov.