• Journal of Environmental Impact Assessment
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• v.26 no.5
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• pp.315-330
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• 2017

The aim of this study is to examine the damage of plants in the islands due to the habitat and feeding of European rabbit (Oryctolagus cuniculus) and to suggest future management plan. The survey area Beomseom Island is found to be a vegetation distribution type that was formed secondary by the exposure of artificial interference except for evergreen vegetation distribution and European rabbit showed high habitat track density mainly in the lumbering area. Kkamakseom Island was identified as a severe vegetation distribution area due to interference, and European rabbit showed high habitat track density around deciduous broad leaved forests. Feeding plants of European rabbit was identified as a total of 12 families 17 breeds. Total 9 families 11 breeds were found in Beomseom Island while 5 families 6 breeds were found in Kkamakseom where most available food resources were loss to European rabbit. As for vegetation index of Beomseom Island, about 6.6% of total island area was declined and the vegetation index of Kkamakseom Island was reduced at most area of the island. In Kkamakseom Island, the area where EVI decreased to less than -0.008 unit/yr was reduced to 5.2%, and the area where it was reduced to -0.008 to -0.006 unit/yr in total was 13.32% of the total area. Thus, it was estimated to be seriously damaged by vegetation. Therefore, immediate management is required.

• Korean journal of applied entomology
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• v.42 no.1
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• pp.1-7
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• 2003

Morphological characteristics, developmental period, and seasonal occurrence of Adeia leucomelas (L.) were investigated from 1999 to 2000. In addition, consumption of sweetpotato as food was also examined. Adults of A. leucomelas were dark-brown and body lengths of females and males were 20.2 mm and 18.9 mm, respectively, Wing expanse of female and male was 33.7 mm and 29.4mm, respectively. Egg was flat round-shape. Larva was light yellow-green to dark-brown with 3.3-53.5 mm. Pupa was deep-brown and 15.1 mm in length. Developmental periods of A. leucomelas from egg to adult emergence at different temperatures of 15, 20, 25, and 30$^{\circ}$C were 108.5, 70.7, 40.2, and 29.1 days, respectively, Developmental threshold (DT) and effective accumulative temperatures were estimated as 10.7$^{\circ}$C and 67.5 DD in egg stage, 11.0$^{\circ}$C and 275.1 DD in larval stage and 9.3$^{\circ}$C and 244.6 DD in pupal stage, respectively. The longevity of adult female was shortened with increment of temperature, whereas the total numbers of eggs laid by a female were increased. The larvae of A.leucomelas occurred from mid-June to early October, and population reached its peak during early to mid-September in Jeonbuk province. Food consumption of A. leucomelas was highest at 20-25$^{\circ}$C. Food consumption of 1 st, 2nd, 3rd, 4th, and 5th larvae of A. leucomelas per day at 25$^{\circ}$C was 0.4, 3.6, 19.6, 40.7, and 78.9 $\textrm{cm}^2$, respectively.

• Korean journal of applied entomology
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• v.42 no.4
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• pp.335-343
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• 2003

An experiment was conducted to investigate types of injury inflicted by the stone leek leafminer, Liriomyza chinensis Kato (Diptera: Agromyzidae) on welsh onion. A feeding scar made by an adult female was a hole round in shape, with diameter of 0.08 mm and 0.48 mm in lesion, resulting in a white spot, many of which often form vertical dotted lines on a leaf. Egg spots were oval with 0.1 ${\times}$0.14 mm in size, one or several of which often form a V-shape in group. Feeding by adults began immediately after emergence and was very active from 4th to 5th day. Oviposition was done from 2nd to 6th day after emergence. In both feeding and oviposition, they were more active in the day time. Larvae after emergence crawled up the leaf at first, and then moved up and down to feed on mesophyll. When in high density, they feed on leaf from leaf tip to bottom, and let the leaf die. Area of damage per one larva was calculated as 72.1 $\textrm{mm}^2$. The aged larvae escaped from the leaf in early morning, usually between 5 and 7 am. Most pupation sites were distributed near plants,5cm in soil depth and within 10 cm away from the plant. Pupae of L. chinensis overwintered 10cm below soil surface and emerged from early May to late June the next year Adults then moved to welsh onions near over wintering sites, nursery, transplanted, and levee.

• Korean journal of applied entomology
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• v.60 no.4
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• pp.431-448
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• 2021

We decided the efficient application timings of organo-synthetic insecticides for controlling the first generation larvae of O. furnacalis through investigations of insect stage-specific densities, damage aspects in maize, and effects of insecticides. A waxy maize cultivar, Ilmichal, was cultivated from April 20 (sowing) to July 26 (harvest, dough stage of maize) in Suwon, 2016. The maximum and 50% cumulative catch dates of the overwintering generation adults in the sex pheromone trapping were May 29 and May 31, respectively. Most of the first generation larvae finished their occurrence till the early reproductive stage of maize. The first generation larvae fed on leaves inside the whorl leaves before tassel and stem development of maize, sequentially moved to tassel and stem, and then moved finally to stem and ear parts. In the results of insecticide applications at different dates, the 9-11 leaf stage (June 10~17) and the 6-7 leaf stage (June 3) of maize were the most efficient application timings for direct spray of Etofenprox EC to maize, and for application of Carbofuran granules onto soil surface, respectively, which resulted in suppression of tunnelling damages. The timings for the two insecticides were 12-19 days and 5 days after the adult maximum catch date, respectively. Those timings after the 50% cumulative adult catch date were advanced 2 days.

• Korean journal of applied entomology
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• v.59 no.4
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• pp.455-460
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• 2020

Rice grain damage caused by Paromius exiguus under various conditions in paddy fields was analyzed. One nymph of P. exiguus caused 2.7 pecky grains in brown rice in one day, and sixteen nymphs caused 132.3 pecky grains over sixteen days. The relationship between the inoculated nymphal density and the number of pecky grains was well described by a linear regression (Y = 8.8446X, r2 = 0.9622). When a pair of P. exiguus adults was inoculated in the heading stage of rice, the damage at the time of harvesting consisted of 40.2% of cracked rice and 30.5% of pecky rice among whole rice grains. Inoculation of 16 pairs resulted in 81.7% of cracked rice and 74.5% of pecky rice. The damage analysis indicated that the quantity of ripened rice decreased as the damage started earlier in the heading stage of rice. On the contrary, the proportion of cracked and pecky rice rapidly increased from the heading time until 28 days after heading of the rice grains.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.3
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• pp.369-374
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• 2014

The rice stem borer (Chilo suppressalis Walker) was one of the most destructive pest of rice for the 1960s and 1970s in Korea. Recently, it is newly recognized as a potential risk factor to the biomass yield of bioenergy crops. The current research was firstly conducted to investigate overwintering larvae population density and pattern of rice stem borer attacking Miscanthus sacchariflorus cv. Geodae 1 which is referred to as an ideal lignocellulosic bioenergy crop in Korea. Population density of larvae per $1m^2$ in stems and rhizomes at the Miscanthus experimental plots and rates of damage (wormhole, abscission) of M. sacchariflorus cv. Goedae 1 were investigated from October 2012 to March 2013. The population of larvae per $1m^2$ in stems of Miscanthus were 23, 4, 1, and 1 in October, November, December 2012, and January 2013, respectively. Over the same period, the population of larvae in basal stem rots and rhizomes were increased, whereas decreased in stems. Interestingly, the positions of larvae for overwintering in Miscanthus were confirmed to 5~10 cm below the soil surface such as basal stem rot and rhizome, whereas the most common overwintering position known in rice is a part of stem on the ground such as rice straw and rice stubble. It would suggest that the larvae gradually moved to bottom of stems and rhizomes in soil in line with decline in temperature. Moreover, the damage rates of stems per $1m^2$ were up to more than 50% in some places. In conclusion, this might be the first report that rice stem borer could affect the productivity of biomass of Miscanthus in case of mass cultivation. Moreover, it should be necessary to make a decision in insect control management for this bioenergy feedstock and other related crops.

• Korean journal of applied entomology
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• v.46 no.2
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• pp.193-199
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• 2007

This study was conducted to explain degree of injury caused by P. panopealis larva which is the key component to develop economic injury level or control threshold in green perilla and was carried out in polyvinyl houses at Yuseong Daejeon, Geumsan and Yesan Chungnam from 2004 to 2006. Of 5 major pests in green perilla polyvinyl house, P. panopealis larva injured green perilla leaf by 48.5% on average under no insecticides application. The peak occurrence of P. panopealis adult was early August and late September in 2004 and 2005 studies. The feeding amount of P. panopealis larva among 1st to 3rd instar was not different, but from the 4th instar the feeding amount greatly increased and this result was consistent with daily feeding experiment in which the amount greatly increased from seventh day. The degree of injury which was investigated with different larval infestation levels showed that the degree of injury increased a little but was not dim ε rent significantly as the density increased. The density of P. panopealis larva in damaged green perilla plant was less than three individuals/plant. This result indicates that P. panopealis adult lays egg on green perilla leaf dispersedly and larva hatched from egg injures only the leaf which egg is layed. These preliminary data seems to be very useful to design economic injury level and control threshold studies for P. panopealis in green perilla polyvinyl house.

• Korean Journal of Microbiology
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• v.48 no.4
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• pp.284-292
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• 2012

To date, chemical control remains the most common way to reduce beet armyworm (Spodoptera exigua) populations. However, this insect has become more tolerant or resistant to many chemical insecticides and the insect larvae usually hide inside hollow, tube-like leaves of host plant so they were difficult to kill by spraying insecticides. The use of viral and bacterial insecticide to solve these problems has not been successful because of their novel feeding habit. To overcome these problems, in this study, the biological characteristics and virulence of an entomopathogenic fungus isolated from the cadaver of larvae beet armyworm were investigated. Isolated entomopathogenic fungus was identified as Nomeraea rileyi (Farlow) Samson by morphological examinations and genetic identification using sequences of the ITS, ${\beta}$-tubulin gene and EF1-${\alpha}$ regions. This fungus was named as N. rileyi SDSe. Virulence tests against 3rd larvae of beet armyworm were conducted with various conidial suspensions from $1{\times}10^4$ to $10^8$ conidia/ml of N. rileyi SDSe in laboratory conditions. Mortality rate of beet armyworm showed from 20 to 54% and the virulence increased with increasing conidial concentrations. Although N. rileyi SDSe showed low mortality rate against beet armyworm, it is expected that N. rileyi SDSe will be used effectively in the integrated pest management programs against the beet armyworm.

• Korean Journal of Environmental Agriculture
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• v.21 no.1
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• pp.50-56
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• 2002

This experiment was carried out to obtain some information about overwintering, physiological and ecological characteristics of apple snails. Another purpose of this experiment was to characterize an appetite for rice plants by apple snails and to elucidate their choice of fresh green ones (vegetables, some other crops, weeds in rice fields). The freshwater snails were found with higher population at sites abundant organic compounds such as plant debris and at regions with high temperature. They also prefer calcium-rich water. This is a naturally occurring process. Apple snails were exceptionally veil-adapted to the south regions of Korea, especially Janghang, Jangseong and Haenam, even if the temperature of winter season is cold below 0$^{\circ}C$. Apple snails were not very selective in their food choice and eat almost everything available in their environment. A snail have something called a radula in its mouth for grinding up its food. A apple snail also chews on fruits and young succulent plant barks. In case of reproduction. apple snails deposit about 157$\sim$784 (average of 321 eggs) milky white to pale orange colored eggs above the waterline. In approximately every 22.4 seconds a new egg appears. The total time needed to deposit a egg mass varies from 58 minutes$\sim$4 hours 13 minutes. Apple snails reproduct actively from May to June and from September to October. An appetite of apple snails for rice plants was the different depending on their size and glowing stage for rice plants. Apple snails had a great appetite of rice plants as well as dropwort, tomato, cabbage, radish, aquatic plants etc. They preferred to eat young rice plants and drastically quit eating rice plants of over 40 cm in height. Thus considering the food preference of apple snail for various plants including rice, they were thought to be a potentially strong predator in fields, especially, at regions with warmer winter.

• Korean journal of applied entomology
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• v.62 no.4
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• pp.371-384
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• 2023

We investigated the occurrence of insect pests on street trees that were planted or naturally grew in a total of six urban and suburban parks (two sites in Iksan, one site in Gimje and three sites in Gwangju) in Honam region, South Korea from May to September, 2022. The six survey sites are divided into three characters, two 'nearby forest (NF)', two 'nearby river (NR)' and two 'nearby downtown (ND)' according to the created location of sites and the results on fauna of insect pests compared with street tree species for each character of survey sites. As results, we could discover 51 species of 49 genera in 27 families belonging to five insect orders from a total of 21 tree species belonging to 13 families in six survey sites. Among the insect taxa, hemipteran pests are most diverse with 22 species of 20 genera in 12 families and it is confirmed that Prunus × yedoensis Matsum. (Rosaceae) is damaged by most diverse 25 insect pests. With regard to character of survey sites, trees in 'nearby river' were affected by most diverse 34 insect pests, even though tree species were few compare to sites of 'nearby forest' and 'nearby downtown. Among the affected area of tree parts, leaf-feeding insect pests are most diverse with 22 species. From the present study, we provided a checklist of insect pests from the street trees and selected six most concerned species. Indeed, it is needed to conduct sustainable surveys and monitoring on occurrence of insect pests from street trees in urban and suburban parks because the species of planted street trees in parks can be extremely diverse with occurrence of unexpected insect pests.