• Korean journal of applied entomology
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• v.13 no.4 s.21
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• pp.209-216
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• 1974

Life history and control methods of Aphanostigma iakusuiense Kishida were studied during April to November, 1974, in the Naju pear orchard area, Cholla Namdo. The results are summarized as follows: 1. More than $60\%$ of wintering eggs were found at the height of 1.5 to 2.0m from the soil surface, with approximately $10\%$ at 0.5 to 1.5m and 1.5 to 2.5m respectively. 2. There was little difference in the size of egg masses and hatching ratio $(12.7-13.7\%)$ between the varieties of host trees, Mansamkil and Kooksoo. 3. Hatching was not observed until April 6, but hatches of $12.8\%$ on April 13 and $90.6\%$ on May 4 were found. 4. During the hatching season in early spring, 8 chemicals were applied to test effectiveness of control. C8514, Metasystox, Acar 338, and Parathion were more effective than either Sevin or Malix for control of this insect. 5. Highest populations of pear phylloxera ocurred from August 20 to September 20 at which time levels of eggs and larvae were simillar in abundance. 6. In tests for control of this insect after in paper bags, DDVP, Loxon, C8514, Sevin, and Binapacryl were more effective than either EPN or Otran. 7. Predacious mite, Protolaelape pygmaeus Miller, and several species of lady beetles (Coccinellidae) preying on this insect as natural enemies were collected. The predation ratio of mites varied according to region: that is 0.77 to $18.6\%$ in Bia Orchard; $7.88-48.7\%$ in Noan Orchard and almost none in Youngsanoo Orchard. 8. The varietal difference in fruit damage by this insect was in the order of Choseng Chuck, Kooksoo, followed by Sin Ko, Mansamkil, Keumchon Choo, and Changsimrang.

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.437-445
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• 2017

An analysis of recent studies and a field survey were conducted to investigate the distribution of the exotic species Ophraella communa LeSage (Coleoptera, Chrysomelidae) and the results' applicability for biological control against ragweed, which disturbs the island's ecosystem. The ragweed beetle (O. communa) can be found anywhere on the host plant Ambrosia artemisiifolia L., which grows in Jeju Island. Moreover, ragweed beetles possess the following characteristics: a high host plant specificity, a high-temperature resistance, an excellent mobility, and multivoltinism. Ragweed is extensively distributed and gradually expands its habitat further on Jeju Island. For this reason, it is recommended to take advantage of O. communa for the biological control of ragweed instead of pesticides or direct removal, considering that Jeju is endowed with many natural reserves and unique insular traits.

• Journal of the Korean Wood Science and Technology
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• v.30 no.2
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• pp.128-133
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• 2002

This study was conducted to investigate the influence of storage time on the sapstain development of Japanese red pine and Korean pine logs during storage in log yard, and their stain characteristics. Japanese red pine and Korean pine trees were harvested and cut into logs in mid January of 2001. These logs were transported to the two local sawmills where they were closely stacked in remote parts of log yard. The logs were then sampled destructively by cutting seven to nine 3-cm long discs along the length of each log at intervals of 3, 4, 5, 6, and 8 month after felling. The stain coverage and maximal radial penetration of stain were measured from the discs of the sampled logs after the isolation of causal staining fungi. The sapstain was primarily infested by the attack of bark beetles and the species of bark beetle was identified as Tomicus piniperda. The main fungal species isolated from stained wood was Ophiostoma species. Based on the present study, the logs could be stored in log yard until May without stain; but stain development was rapid after May and the severity of stain increased proportionally with storage time. Korean pine was more susceptible to fungal stain than Japanese red pine. During summer storage, decay started to develop in logs and the main species were identified as Tyromyces sp. and Schizophyllum commune. Information provided in this paper would be very useful to develop more effective control strategies for sapstain prevention in Japanese red pine and Korean pine logs.

• 한국균학회소식:학술대회논문집
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• 2014.05a
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• pp.27-28
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• 2014

Beauveria bassiana (Cordycipitaceae, Hypocreales, Ascomycota) is an anamorphic fungus having a potential to be used as a biological control agent because it parasitizes a wide range of arthropod hosts including termites, aphids, beetles and many other insects. A number of bioactive secondary metabolites (SMs) have been isolated from B. bassiana and functionally verified. Among them, beauvericin and bassianolide are cyclic depsipeptides with antibiotic and insecticidal effects belonging to the enniatin family. Non-ribosomal peptide synthetases (NRPSs) play a crucial role in the synthesis of these secondary metabolites. NRPSs are modularly organized multienzyme complexes in which each module is responsible for the elongation of proteinogenic and non-protein amino acids, as well as carboxyl and hydroxyacids. A minimum of three domains are necessary for one NRPS elongation module: an adenylation (A) domain for substrate recognition and activation; a tholation (T) domain that tethers the growing peptide chain and the incoming aminoacyl unit; and a condensation (C) domain to catalyze peptide bond formation. Some of the optional domains include epimerization (E), heterocyclization (Cy) and oxidation (Ox) domains, which may modify the enzyme-bound precursors or intermediates. In the present study, we analyzed genomes of B. bassiana and its allied species in Hypocreales to verify the distribution of NRPS-encoding genes involving biosynthesis of beauvericin and bassianolide, and to unveil the evolutionary processes of the gene clusters. Initially, we retrieved completely or partially assembled genomic sequences of fungal species belonging to Hypocreales from public databases. SM biosynthesizing genes were predicted from the selected genomes using antiSMASH program. Adenylation (A) domains were extracted from the predicted NRPS, NRPS-like and NRPS-PKS hybrid genes, and used them to construct a phylogenetic tree. Based on the preliminary results of SM biosynthetic gene prediction in B. bassiana, we analyzed the conserved gene orders of beauvericin and bassianolide biosynthetic gene clusters among the hypocrealean fungi. Reciprocal best blast hit (RBH) approach was performed to identify the regions orthologous to the biosynthetic gene cluster in the selected fungal genomes. A clear recombination pattern was recognized in the inferred A-domain tree in which A-domains in the 1st and 2nd modules of beauvericin and bassianolide synthetases were grouped in CYCLO and EAS clades, respectively, suggesting that two modules of each synthetase have evolved independently. In addition, inferred topologies were congruent with the species phylogeny of Cordycipitaceae, indicating that the gene fusion event have occurred before the species divergence. Beauvericin and bassianolide synthetases turned out to possess identical domain organization as C-A-T-C-A-NM-T-T-C. We also predicted precursors of beauvericin and bassianolide synthetases based on the extracted signature residues in A-domain core motifs. The result showed that the A-domains in the 1st module of both synthetases select D-2-hydroxyisovalerate (D-Hiv), while A-domains in the 2nd modules specifically activate L-phenylalanine (Phe) in beauvericin synthetase and leucine (Leu) in bassianolide synthetase. antiSMASH ver. 2.0 predicted 15 genes in the beauvericin biosynthetic gene cluster of the B. bassiana genome dispersed across a total length of approximately 50kb. The beauvericin biosynthetic gene cluster contains beauvericin synthetase as well as kivr gene encoding NADPH-dependent ketoisovalerate reductase which is necessary to convert 2-ketoisovalarate to D-Hiv and a gene encoding a putative Gal4-like transcriptional regulator. Our syntenic comparison showed that species in Cordycipitaceae have almost conserved beauvericin biosynthetic gene cluster although the gene order and direction were sometimes variable. It is intriguing that there is no region orthologous to beauvericin synthetase gene in Cordyceps militaris genome. It is likely that beauvericin synthetase was present in common ancestor of Cordycipitaceae but selective gene loss has occurred in several species including C. militaris. Putative bassianolide biosynthetic gene cluster consisted of 16 genes including bassianolide synthetase, cytochrome P450 monooxygenase, and putative Gal4-like transcriptional regulator genes. Our synteny analysis found that only B. bassiana possessed a bassianolide synthetase gene among the studied fungi. This result is consistent with the groupings in A-domain tree in which bassianolide synthetase gene found in B. bassiana was not grouped with NRPS genes predicted in other species. We hypothesized that bassianolide biosynthesizing cluster genes in B. bassiana are possibly acquired by horizontal gene transfer (HGT) from distantly related fungi. The present study showed that B. bassiana is the only species capable of producing both beauvericin and bassianolide. This property led to B. bassiana infect multiple hosts and to be a potential biological control agent against agricultural pests.

• Korean Journal of Food Science and Technology
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• v.52 no.4
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• pp.317-324
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• 2020

In order to create the national food nutrient database, a total of 41 animal foods (ham, seafood, edible insects and eggs) were analyzed for their vitamin B₁₂ content and the applied immunoaffinity-HPLC was verified. Ham vitamin B₁₂ contents were 0.30-0.65 ㎍/100 g. Seafood showed relatively high vitamin B₁₂ level, where the values of fermented clam were the highest (26.80 ㎍/100 g) followed by fermented pollack roe. Vitamin B₁₂ was not detected in silkworm pupae and beetles, while relatively high levels were found in the two-spotted cricket imago (6.70 ㎍/100 g). Chicken and quail egg yolk had roughly 100- and 30-times higher vitamin B₁₂ levels as compared to their egg white. Vitamin B₁₂ contents in quail and chicken eggs were significantly enhanced by boiling (p<0.05). Results based on accuracy (97-102% recovery) and precision (<5% RSD) indicate that this study provides reliable vitamin B₁₂ information on animal foods consumed in Korea.

• Journal of Korean Society of Forest Science
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• v.27 no.1
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• pp.15-21
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• 1975

According to Yoshihisa Kuroki's report that the total amount of carotenoid was more in the susceptible to pine bark beetle, than in the resistant ones, carotenoids were extracted from needle leaves of one year old seedlings of Pinus thunbergii, Pinus desiflora, Pinus rigida, Pinus koraiensis, Pinus rigitaeda and Pinus taeda which are all important pines in Korea, to find their resistant ratio to the insect. The carotenoids were analyzed and compared using the spectra of them by spectrophotometer. The results were as follows: 1. The visible absorption spectra of carotenoids in those pine trees were proved to be very similar. 2. The total amount of carotenoids in needles differed with the tree species and the contents were arranged in decreasing order P. koraiensis>P. rigida>P. thunbergii>P. rigitaeda>P. taeda, it seemed that there was corelation between the cartenoid content and the extent of harm caused by the pine bark beetles except P. koraiensis. 3. But carotenoids were contained in Robinia pseudoacacia, Castanea crenata, Chamaecyparis obtusa and Cedrus deodra leaves too. 4. The total amounts of carotenoids in these pines of 9 species were arranged in decreasing order Robinia pseudoacacia>Pinus koraiensis>Pinus rigida>Pinus thunbergii>Castanea crenata>Pinus rigitaeda>Pinus taeda>Chamaecyparis obtusa>Cedrus deodara. Therefore, it was proved that there was no correlation between carotenoid cotent and extent of resistance to the insect. 5. In the thin-layer chromatography of these carotenoids, 13 kinds of components in P. densiftora, P. koraiensis and P. rigida and 12 kinds of spots in other pines, were detected respectively, under ultra-violet fluorescent lamp $3,600{\AA}$ and $2,537{\AA}$. 6. The eighth spots from the bottom in P. densiflora, P. koraiensis and P. rigida were not found in other pines and other 4 species (Robinia pseudoacacia, Castanea crenata, Chamacyparis obtusa, Cedrus deodra). Especially the spot in P. densiflora fluoresced strong cobalt blue-fluorescence under ultra-violet fluorescent lamp $2,537{\AA}$.

• Korean journal of applied entomology
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• v.31 no.4
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• pp.496-508
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• 1992

Phytophagous insects associated with Dicotyledoneae weeds and host specificities in the field populations were investigated for the survey of biological control agents of weeds in Korea. Fifty four weed species in 39 genera were collected during the survey. The most insects were collected from Polygonales by 24 species in 22 genera and followed by Urticales and Centrospermales by 17 species of 17 genera. The insects collected in the other weed orders were ranged from 1 to 12 species. Out of 17 insect species collected in Urticales, Baris sp. damaged the leaves of Hamulus japonicus in Cannabinaceae as scattered holeshape and showed host specificity. In Polygonaceae, Rumex japonicus and R. crispus were severely damaged by Aphis rumicis and Gastrophysa atrocyanea. G. atrocyanea leaf beetle had host specificity on R. japonicus and ate all the leaves except veins. The leaf beetle, Lypesthes japonicus was a potential biological control agent by feeding leaves of Persicaria spp .. And Lixus spp. were also often collected from Persicaria spp .. Liothrips vaneeckei was first collected from weed, P. modosa. P. senticosa was damaged by unidentified geometrid moth larvae and P. perfoiliata by Miarus atricolor snout beetle. Cassida piperata damaged leaves of Chenopodium album of Centrospermales and showed host specificity. In a soybean field, C. album and Amaranthus mangostanus were severely damaged by Spodoptera litura larvae which were eating soybean leaves. This phenomenon indicates that the presence of weed in cultivated land influences the outbreak of insect pests. Altica oleracea leaf beetle was frequently collected from Oenothera spp. of Onagraceae in Myrtales. Aphis gossyphi was outbroken on Solanum nigrum and Phylliodes brettinghami leaf beetle was first recorded on the same plant. Leaf beetles, Longitarsus scutellais and Hemipyxis plagioderoides were first collected from Plantago asiatica of Plantaginaceae in Plantaginales. They showed host specificities in the fields. The hemipterans were collected from many weeds during the survey and their roles on weeds should be investigated. A tractomorpha bedeli was also collected from many kinds of weeds in forest areas.