• Korean journal of applied entomology
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• v.59 no.3
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• pp.257-264
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• 2020

The purpose of this study was to investigate the attraction distance range of pheromone traps used in the control of stink bugs, which are a problem in persimmon orchards, and the effects of sticky traps in increasing the efficiency of pheromone traps. Labeled individuals were released and then recaptured on pheromone and sticky traps. Riptortus clavatus was attracted to pheromone traps up to 60 m away. The capture rates of R. clavatus on sticky traps were 35%, 27%, 34%, 2.9%, and 0.6% after 0, 1, 2, 3, and 4 weeks To improve clarity, II have added this information from the details shown in the figures. Please check whether you agree.of exposure of the traps to the environment, respectively. Besides, when both pheromone and sticky traps were used at the same time following the release-recapture method, the capture rate of R. clavatus was 12 times higher than that by using pheromone traps only.

• The Korean Journal of Mycology
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• v.34 no.2
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• pp.112-118
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• 2006

To select efficient entomopathogenic fungal strains of Lecanicillium for the biocontrol of aphid, Myzus persicae, conidial suspension ($1{\times}10\;conidia/ml$) was sprayed onto a detached Chinese cabbage leaf in a petri dish with a dampened filter paper that had 20 nymphs of aphid. Lecancillium strain 4078 and 6543 were the best strains for the biocontrol of aphid at high temperature of $30^{\circ}C$ and low relative humidity (RH) of 85%, respectively. The cumulative mortality of strain 4078 at $30^{\circ}C$ after 3 days was 100% and that of strain 6543 was 90% at 85% RH after 5 days. Strain 4078 also exhibited almost 100% germination ratio of conidia and high rate of mycelial growth at the broad temperature-range of $15{\sim}25^{\circ}C$. The strain 4078 and 6543 were all identified as Lecanicillium species based on the DNA sequences (accession no.: EF026004 and EF026005, respectively) of the ITS regions of the fungi. Excellent production of aerial conidia of strain 6543 was accomplished by using steamed polished rice as the solid culture medium.

• Weed & Turfgrass Science
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• v.4 no.2
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• pp.129-134
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• 2015

White grub damages various crops, trees and they can also be one of the most serious pests of turf grass in golf courses. This study was conducted to determine the biocontrol of white grubs with 18 different kinds (anise, camphor, castor, cinnamon, clove oil, citronella, fennel, geranium, lavender, lemongrass, linseed, neem, peppermint, pine, rosemary, tea-tree, thyme, and turpentine) of plant essential oils in laboratory, green house and field. Anise oil (88.9%), linseed oil (100%), and tea-tree oil (88.9%) were highly effective among tested essential oils against 3rd instar of Bifurcanmala aulax in cap vial experiment. However, anise and linseed oils showed low mortality against $3^{rd}$ instar of Popillia japonica in pot greenhouse experiment. Efficacy of anise, linseed oil, and tea-tree was also different depending on target white grub in field trials. Correlated mortality showed 32.6% only in tea-tree oil treatment against pupae of Adoretus tenuimaculatus however, correlated mortality of anise, linseed and tea-tree oil were 54.8, 51.6 and 56.5% respectively against $3^{rd}$ instar of Exomala orientalis in the field trial in Adelscott Country Club in Hapcheon, Gyeongnam province.

• KSBB Journal
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• v.15 no.1
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• pp.106-111
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• 2000

Peach fruit month, smaller tea tortrix, and Melotontha incana are major pests of apple and apple trees throughout the country. In this work, we examined efficacies of entomopathogenic nematodes Steinernema carpocapsae and Steinernema glaseri against these apple pests. Steinernema carpocapsae showed 100% mortality after 24hr against peach fruit moth when it was applied on the larva with the concentration of 80 nematodes per larva, but Steinernema glaseri caused 83.3$\pm$5.8% mortality after 24hr at the concentration of 50 nematodes per larva. In the case of smaller tea tortrix, S. carpocapsae and S. glaseri caused 100%, 43.3$\pm$5.8% at the concentration of 50 nematodes per larva after 48 hr, respectively. However, 5~6 instar of Melotontha incana was not killed by treatments with S. carpocapsae and S.glaseri up to concentration of 200~800 nematodes per larva. The motility of nematodes in a soil increased as both inoculation concentration of nematode per larva and temperature increased. The mortality of G. mellonella by S. carpocapsae was 100% up to 10cm in depth and 56.7$\pm$5.8% at 10~15cm in depth when the temperature was $25^{\circ}C$ and 50 nematodes per larva were used.

• Korean Journal of Organic Agriculture
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• v.22 no.3
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• pp.445-455
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• 2014

The pear sucker (Cacopsylla pyricola) is the most important insect pest in Korea. The hatching rates of overwintered adults laid eggs were observed at 10, 13, 18, and $22^{\circ}C$. The liner model was draw as Y=0.00277X+0.00146(Y=developmental rate, X=temperature) about temperature and developmental rate to eggs. The developmental threshold temperature to eggs was assumed about $-0.83^{\circ}C$. The egg hatching timing over 50% as the accumulated temperature by day maximum temperature $6^{\circ}C$ over from 1st February in 2008, 2009 and 2011 was 429.7, 417.6, and 424.3 degree $^{\circ}C$, respectively, was 3 to 7days before full blooming in pear orchard. On the other hand, the abamectin 1.8EC, lime sulfer, machine oil and 13 kinds of eco-friendly materials were not shown the control effect to the eggs. To mixed stage of pear sucker, the eco-friendly materials over 90% control value were 4 kinds such as a mixture of Azadiractin A+B, Nimbin, Salanin, Meliantriol and Vepol after twice application as 21st May and 5th June in pear growing season, in 2012.

• Korean journal of applied entomology
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• v.60 no.2
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• pp.215-220
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• 2021

To establish the systematic biological control system for various insect pests in strawberry under plastic houses, we were investigated the biological traits of lesser strawberry aphid, Chaetosiphon minus (Forbes), as a target pest. The lesser strawberry aphid is adapted to low temperatures while examining the availability of and selecting useful natural enemies. The development, survivorship and reproduction of lesser strawberry aphid were evaluated at four constant temperatures (10, 15, 20, and 25℃). The developmental periods of the nymphal stages ranged from 41.7 d at 10℃ to 9.8 d at 25℃. The developmental threshold temperature and degree day of nymphal stages are 5.5℃ and 185 DD. The reproduction rate (R₀) was higher at 20℃ (30.16) than at 25℃ (22.38). The 50 % survival rate and maximum longevity of adult females were 31 d and 59 d at 20℃, and 25 d and 36 d at 25℃, respectively. The average progeny per female was 35 at 20℃, and 26 at 25℃. We confirmed that compared to other strawberry aphids under plastic houses, the lesser strawberry aphid is more adapted to lower temperatures. It is, therefore, necessary to commercialize natural enemies such as syrphid flies with high activity at low temperatures.

• Korean journal of applied entomology
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• v.58 no.3
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• pp.251-258
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• 2019

A series of studies were conducted to monitor the seasonal occurrences of onion thrips (Thrips tabaci) and allium leafminers (Acrolepiopsis sapporensis) in northern-type garlic fields, and to evaluate their susceptibility to insecticides. The results showed that the T. tabaci population density increased from mid- March to mid-June, that of A. sapporensis began to increase in mid-March and peaked twice by early July. Also, using recommended concentrations, the insecticidal activities of nine insecticides against these two pests were evaluated. Under laboratory conditions, clothianidin SC, chlorfenapyr EC, dimethoate EC, imidacloprid WP, and cyantraniliprole + thiamethoxam WG insecticidal activities against T. tabaci were all 100%, as well as. those of cyantraniliprole EC, pyridalyl EW, spinetoram SG and abamectin + chlorantraniliprole SC against A. sapporensis. Insecticides, with high insecticidal activities, were evaluated on the two pests under laboratory conditions, and the results showed that all the insecticides exhibited strong insecticidal activities, and the mortality of two pests was >90%.

• Korean journal of applied entomology
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• v.58 no.3
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• pp.233-238
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• 2019

For greenhouse crops, thrips is one of the major insect pests, but its control is difficult owing to short generation time, rapid escaping behavior, and development of pesticide resistance. Stratiolaelaps scimitus (Womersley) is a soil-dwelling predatory mite attacking various soil invertebrate species, including thrips. Using the method by growers' self-production, we mass-reared S. scimitus colony and investigated thrips control in the greenhouse chrysanthemum. The initial density of thrips was six individuals/flower. The treatment with one S. scimitus box in the greenhouse was estimated to be $1,000individuals/m^2$. From August to September 2018, the greenhouse was released with a total of 10 boxes of S. scimitus. The density of thrips in the untreated and the treated cultivar was $53.7{\pm}7.0$ and $13.5{\pm}1.7$ on the late September, respectively, which indicated a reduction of 74.9% in the treated cultivar. Our results suggest that S. scimitus was highly effective for the control of thrips in the greenhouse chrysanthemum although temperature is very high during the summer season.

• Korean journal of applied entomology
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• v.60 no.2
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• pp.167-173
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• 2021

Sweet potato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is an insect pest with sucking mouth part and globally attacks diverse crops and vegetables. Since first reported in 1998, it is now widely spread in many regions in Korea. Due to insecticide resistance, it is necessary for optimal control of the whiteflies to select effective insecticides with precise insecticide resistance monitoring. In this study, B. tabaci individuals were collected from 12 regions in 7 provinces of Korea from June to September in 2020. Using these field populations, insecticide resistance levels were monitored using a residual contact bioassay along with molecular markers. Bioassay results revealed that B. tabaci possessed high levels of resistance to five insecticides exhibiting different modes of action: dinotefuran, spinosad, emamectin benzoate, chlorfenapyr, and bifenthrin. In addition, quantitative sequencing in target sites of organophosphate and pyrethroid insecticides revealed that point mutations reached to saturated or near-saturated levels across the country. This suggests that insecticide resistance management is required for effective control of B. tabaci populations in Korea.

• Korean journal of applied entomology
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• v.62 no.4
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• pp.277-285
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• 2023

The onion moth, Acrolepiopsis sapporensis, was monitored in the farms cultivating the welsh onion, Allium fistulosum, using sex pheromone from transplantation to harvest. Two occurrence peaks were observed at early June and late July after the overwintering population. However, the population sizes were varied among different years and the cultivating environments. To effectively control A. sapporensis with microbial pesticides, different Bacillus thuringiensis strains were screened to select B. thuringiensis kurstaki (BtK). To enhance the insecticidal virulence of BtK, the culture broth of Photorhabdus temperata temperata (Ptt) was added to the BtK. This mixture of two entomopathogenic bacteria was called 'BtPlus', which was superior to BtK alone in the insecticidal virulence. The enhanced virulence was explained by the immunosuppressive activity of the secondary metabolites contained in the Ptt extract. The metabolites inhibited both cellular and humoral immune responses of A. sapporensis, resulting in the enhanced virulence of BtK. These results suggest that A. sapporensis occurs in the welsh onion fields and the resulting economic damage would be effectively prevented by BtPlus application.