• Korean journal of applied entomology
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• v.52 no.1
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• pp.45-51
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• 2013

Tropical plants of mango(Mangefera indica), dragon fruit(Hylocereus undatus), and atemoya(Annona cherimola ${\times}$ A. squamosa) are cultivated in Jeju, Korea. A pest survey on those tropical fruits was conducted from 2008 to 2011. Major pests of Mango were thrips, aphid, mealybug, and lepidoptera species. Thrips palmi and Scirtothrips dorsalis were the most important pests in mango fields. T. palmi mainly injured the leaf but S. dorsalis injured the leaf and fruit. Lepidoptera mango pests injured leaves but some larva of Adoxophyes honmai injured fruit surface around the stem. Aphid pests, Aphis gossypii and Myzus persicae, injured the shoots and Pseudococcus kraunhiae occurred on the stem and fruit. Ant species, A. gossypii, and S. litura, were important pests on dragon fruit. Ants and aphid occurred and injured the stem, flower, and fruit. Spodoptera litura larva severely injured the stem. Among the atemoya pests, S. litura and Homona magnanima caused severe damage.

• Korean journal of applied entomology
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• v.62 no.2
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• pp.103-107
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• 2023

Fifteen insect species have been identified as olive pests through a survey conducted in olive orchards on Jeju island from 2019 to 2022. The occurrence and fruit damage caused by Lepidopteran and hemipteran were significant severity. Among the moths, the order in which the population was large was as follows: Alpita nigropunctalis, Aterpia circumfluxana, Homona magnanima, and Adoxophyes honmai. These lepidopteran species primarily caused damage to leaves, but P. nigropunctalis inflicted severe damage to the fruits by feeding on the inside. Three stink bugs, namely Plautia stali, Halyomorpha halys, and Chinavia hilaris, were commonly observed and responsible for damaging olive furits. Chrysomphalus bifasciculatus and Pseudaulacaspis pentagona were found to occur and damaged fruit in non-controlled orchard. Prociphilus oleae, which is being recognized for the first time in Korea, and Ricania shantungensis discovered for the first timein olive orchard. Saissetia olea, a quarantine pest, was found in one farm, but subsequent pesticide spraying resulted in their elimination. Although severe damage was inflicted upon the olives, no perforated pests were found during the survey.

• Horticultural Science & Technology
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• v.31 no.1
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• pp.32-37
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• 2013

Relationships among climate changes, early frost, and fruit growth were studied during the final month to harvest of late-maturing 'Fuyu' persimmon (Diospyros kaki) to assess the changes in fruit characteristics during this critical period. The heavy frost on Nov. 16 defoliated more than 70% of the leaves, but with little damage on the fruits. However, all the leaves were defoliated by the heavy frost on Nov. 20, and all the fruits were cold-damaged by $-3.3^{\circ}C$ on Nov. 21. Fruit weight increased by 8-25 g per week from Oct. 25 (142 days after full bloom) to Nov. 15, reaching to 250 g, but it decreased by 3-4 g per week after the frost. Hunter a value of fruit skin gradually increased until the last harvest on Nov. 29 with a temporary halt in early Nov. when temperature was high, whereas fruit firmness rapidly decreased after the frost on Nov. 21. Fruit soluble solids were $15.7-16.1^{\circ}Brix$ for the final month. When some branches were covered with non-woven fabrics to avoid direct contact with frost, the fruits on the branches were not visually damaged by the low temperature although 40-60% of their leaves were defoliated on Nov. 16. However, low temperature on Nov. 20 and 21 defoliated all the leaves, causing cold damage on the fruits. There was a highly significant correlation between the fruit diameter and its weight ($R^2$ = 0.73-0.91). So, the regression equations could be used to estimate weight from diameter of the fruits sampled from the branches with the non-woven fabrics. The calculated fruit weight reached to a maximum of 240 g on Nov. 15. Daily increases in fruit weight were 1.1-2.5 g from Oct. 25 to 31, 1.9-3.5 g from Oct. 31 to Nov. 7, and 1.4-1.6 g from Nov. 7 to 12. However, fruit weight decreased by 0.3-1 g per day after the cold damage on Nov. 21. The results indicate that the most appropriate harvest time could be dependent on relationship of fruit growth to climate.

• Horticultural Science & Technology
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• v.31 no.4
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• pp.437-446
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• 2013

This study was conducted for three years (2007, 2009, and 2010) to investigate the changes in fruit quality during maturation, and the quality and storage ability of fruits harvested at different times of 'Fuji' apple in Daegu region with a high air temperature during the fall season. Changes in apple fruit quality during the maturation period were investigated from 120-135 days to 183-198 days after full bloom. In comparing quality and storage ability of fruits harvested at different times, fruits harvested more than 180 days after full bloom were used. During the maturation period, poor coloring was the problem for 'Fuji' apple in Daegu region by the high air temperature about $20^{\circ}C$. In comparing quality of fruits harvested at different times, the soluble solid contents and hunter a value were increased by the extended harvest time. Fruit weight during harvest was not affected by different harvest time, while the fruit firmness and titratable acidity during harvest were decreased critically when the freezing damage happened. Ethylene production, fruit firmness, and titratable acidity during cold storage for twenty weeks did not differ according to the different harvest time. Soluble solid contents of fruits harvested at 216 days after full bloom in 2009 were similar at the time of harvest and cold storage. For fruits harvested at 201 days after full bloom, soluble solid content during cold storage was higher than during harvest time. However fruit firmness, soluble solid content, and titratable acidity after cold storage of fruit harvested after freezing damage was lower than those of the fruit harvested before freezing damage. The results show that the extended harvest time of 'Fuji' apples about 2-4 weeks from 180-200 days after full bloom in area with above-air temperature during fall season was seemed to be beneficial to enhancing soluble solid contents and fruit red color, but harvesting after the middle of November was dangerous because minimum air temperature began to fall under $-3.0^{\circ}C$.

• Korean journal of applied entomology
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• v.9 no.2
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• pp.99-102
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• 1970

The present further survey is carried out to clarify the unidentified kinds of the fruit sucking moths and these damages at Suwon and Jinju fruit growing areas, in order to set up the basis of the control for the harmful moths. It was known that 10 species be recorded up to 1968 11 and, in addition, identified 4 species in 1969, such as Apatele rumicis oriens S., Leucania separate W., Scoliopteryx libatrix L. and Anomis flava F. of the fruit sucking moths in Korea. The damage ratio ib percentage of the noxious moths if $5.1\%$ on grape in Suwon and $11.8\%$ on Pears in Jinju in 1969, although it was $8.9\%$ in Suwon and 3.4\%$ in Jinju in 1968.

• Journal of Navigation and Port Research
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• v.28 no.3
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• pp.161-167
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• 2004

Maritime safety and marine environmental protection are the most important topic in marine society. But, so many marine accidents have been occurred with the development of marine transportation industry. On the other side, ship is being operated under a highly dynamic environment and many factors are related with ship's collision Nowadays, the increasing tendency to the human errors of ship's collision is remarkable, and the investigation of the human errors has been heavily concentrated. This study analysed on the human errors of ship's collision related to the negligence of lookout and classified basic error type using GEMS(Generic Error Modeling System) dynamic model.

• Korean journal of applied entomology
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• v.9 no.1
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• pp.37-41
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• 1970

The great damage to the mature fruits in the orchard caused by the fruit sucking moths including unidentified species, is a troublesome problem in recent years in Korea. The present survey is, there-fort, carried out to clarify the ecological characters, especially kinds of these harmful moths and their damage at Suwon and Jinju fruit growing areas, in order to establish the foundation of the control. Some results obtained through the survey are as follows: It is investigated that the most noticeable group of these noxious moths, identified 10 species, belongs to subfamily Catocalinae of the family Noctuidae. Although there was already recorded as the harmful moths on the fruits such 4 species as Oraesia excavata B. Adris tyrannus amurensis S., Calpe thalictri B. and Dermaleipa juno Delman, it is additionally identified to be 6 species in 1968 including Oraesia emarginata F.,O. lata B., Agrotis ipsilon H., Chrysorithrum amatum Bremer et Grey, Dinumma deponens W. and Trachea atriplicis L. of the fruit sucking moths in Korea. Of all these noxious moths damaged, O. excavata is the most harmful, following by O. emarginata and Adris tyrannus. The fruit sucking moths attack on all kinds of mature fruits from early summer to late fall and behave entirely nocturnal. The damage ratio in percentage of these moths is $8.9\%$ on grape in Suwon, and $3.4\%$ on pears in Jinju.

• Korean journal of applied entomology
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• v.53 no.4
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• pp.485-490
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• 2014

This study was conducted to assess the occurrence and damages by thrips on greenhouse-cultivated fig in Hwaseong, Gyeonggi Province, Korea. We identified the collected species as Thrips tabaci Lindeman, Frankliniella occidentalis Pergande, and F. intonsa Trybom. The density of thrips in the greenhouses during the summer months was monitored using yellow sticky traps; T. tabaci showed the highest density, followed by F. occidentalis and F. intonsa. The damages by thrips were characterized by stunted plant growth because of delayed discoloration of the pericarp, and development of rough fruit surface. Stereomicroscopic observation on the fruit flesh revealed the growth of gray mold at the damaged area, as well as the dead bodies and exuviae of thrips. The rates of fig fruit damages per month, were 18.2%, 9.7%, 2.9%, and 1.3% in July, August, September, and October, respectively.

• Korean journal of applied entomology
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• v.39 no.4
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• pp.267-274
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• 2000

As the pest of the citrus in Cheju, 69 insect species and 5 animal species were investigated during 1996 to 1998. Of these, Panonychus citri, Phyllocnistis citrella, Aphis citricola, Aphis gossypii and Frankliniella occidentalis are major pests. Especially, F. occidentalis and Peridroma saucia are very important species because of increasing damage. The number of pests species injuring leaf, branch, fruit and flower of the citrus are 36, 16, 41 and 2 species respectively. The rate of damaged fruits by pests is 20.5% in 1997 and 18.6% in 1998 and the rate of bad quality fruits is 6.4% and 6.7% respectively.

• Korean Journal of Organic Agriculture
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• v.25 no.4
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• pp.773-788
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• 2017

This study was carried out to investigate the damage patterns, the occurrence and migration time of Pseudococcus comstocki and in order to improve the control effect of organic agricultural materials (OAMs). The experiment was carried out at Okcheon's organic vineyard ($2,500m^2$, sandy loam, manure) where planted 8~9 year old 'Muscat of Alexandria' vines. The comstock mealybug's migration to grape clusters occurred from the middle of July, and produced eggs in the grape clusters from the end of July, and the density of the comstock mealybug was highest at $0.6cm^2$ in late August. The number and fruit damage of comstock mealybug in eco-friendly vineyards were higher than in conventional culture vineyard. And the marketability of green variety grape was more damaged from comstock mealybug than the black variety grape. Toxicities of 8 OAMs were evaluated to comstock mealybug at the recommended concentration. As a results, Lightyellow sophora and Derris extracts exhibited strong insecticidal activity with 100% mortality. When the Lightyellow sophora extract was uniformly distributed on the vine from early-July to mid-July, fruit damage reduction rate was 96.2% and 84.6%, respectively. So commercial grapes could be harvested. Therefore, it was considered to be effective to reduce fruit damage by controlling in early - late July (the green stage) when the comstock mealybug migrated to grape clusters in the vine greenhouse. In the future, it will be necessary to study the effect of external exposure time and momentum on the control of OAMs.