• Korean journal of applied entomology
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• v.61 no.4
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• pp.595-599
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• 2022

In this study, Tetraneura triangula Zhang & Zhang, 1991 is reported for the first time in Korea. Species distribution, measurement, host plants, description, and illustrations of diagnostic characters for emigrant and embryo are provided.

• Korean journal of applied entomology
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• v.61 no.4
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• pp.591-593
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• 2022

In this study, Kaltenbachiella japonica (Matsumura, 1917) is reported for the first time in Korea. Species distribution, measurement, host plants, description, and illustrations of diagnostic characters for fundatrix are provided.

• Korean journal of applied entomology
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• v.61 no.3
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• pp.475-479
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• 2022

In this study, Periphyllus acerihabitans Zhang, 1982 is reported for the first time in Korea. Species distribution, measurement, host plants, description, key to Korean species of the genus Periphyllus, and illustrations of diagnostic characters for apterous viviparous females are provided.

• Korean journal of applied entomology
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• v.62 no.1
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• pp.5-8
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• 2023

In this study, the gall-forming aphid species, Pemphigus bursarius (Linnaeus, 1758) is reported for the first time in Korea. Species description, measurement, diagnosis, distributions, host plants, illustrations, and identification key of fundatrix are provided.

• Korean journal of applied entomology
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• v.62 no.3
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• pp.207-211
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• 2023

To date, Periphyllus allogenes is known only in Korean peninsula, has been reported with morphological characteristics about only the aptera viviparous generation. In this study, we collected fundatrix and alate viviparous female individuals of P. allogenes samples from Gapyeong-gun, and Hongcheon-gun in Korea between 2021 and 2022. Herein, we provide new descriptions, measurements, distributions, host plants, and photographs of unknown morphs, fundatrix and alate viviparous generations of P. allogenes.

• Korean journal of applied entomology
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• v.57 no.4
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• pp.261-269
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• 2018

The cowpea aphid Aphis craccivora Koch (Hemiptera: Aphididae) is a polyphagous species with a worldwide distribution. We investigated the temperature effects on development periods of nymphs, and the longevity and fecundity of apterous female of A. craccivora. The study was conducted at six constant temperatures of 10.0, 15.0, 20.0, 25, 30.0, and $32.5^{\circ}C$. A. craccivora developed successfully from nymph to adult stage at all temperatures subjected. The developmental rate of A. craccivora increased as temperature increased. The lower developmental threshold (LT) and thermal constant (K) of A. craccivora nymph stage were estimated by linear regression as $5.3^{\circ}C$ and 128.4 degree-days (DD), respectively. Lower and higher threshold temperatures (TL, TH and TH-TL, respectively) were calculated by the Sharpe_Schoolfield_Ikemoto (SSI) model as $17.0^{\circ}C$, $34.6^{\circ}C$ and $17.5^{\circ}C$. Developmental completion of nymph stages was described using a three-parameter Weibull function. Life table parameters were estimated. The intrinsic rate of increase was highest at $25^{\circ}C$, while the net reproductive rate was highest at $20^{\circ}C$. Biological characteristics of A. craccivora populations from different geographic areas were discussed.

• Korean journal of applied entomology
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• v.48 no.2
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• pp.171-178
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• 2009

The changes of feeding pattern and the amount of insecticide penetrated into the leaf were monitored for 420 min after treatment of three concentrations of dinotefuran. At about 30 min after treatment of insecticide, the overall feeding pattern in EPG (Electrical Penetration Graph) monitoring was started to change, and there was significant difference in proportions of NP (non-penetration), PA (pathway activity), and phloem-feeding patterns among the different concentrations of dinotefuran treatment. Especially, as the amount of insecticide penetrated into a leaf increased, the reactive behaviors against this insecticide such as withdrawal of proboscis and movements of stylet of aphid were more quickly exhibited. And also, total time at which the proboscis of the aphids did not penetrate the plant was getting longer. The amount of dinotefuran penetrated into a leaf was monitored with HPLC. When the recommended concentration (100 mg/L) of the insecticide was treated, 5.24${\sim}$7.24 mg/L of the insecticide was detected from the leaf, and the proboscis of the aphids was apparently withdrawn from the leaf at approximately 60 minutes after treatment of this insecticide.

• Korean journal of applied entomology
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• v.44 no.4 s.141
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• pp.271-276
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• 2005

To investigate feeding behaviour of the greenpeach aphid (Myzus persicae) on several plants, DC electrical penetration graph (EPG) technique was used. We chose 5 plants including pepper, melon, cabbage, radish, and eggplant which were known as major host Plants of this species. This study was focused whether feeding patterns of the aphid were different and which plants would be the most preferable among 5 host plants. The time from initial proboscis contact with a each leaf until the first electrical contact, as a measure of the time taken for the stylet penetration, the time from electrical contact to the first potential drop as a time consumed until intracellular sampling, the number of potential drops per an hour during periods of regular intercellular pathway probing, and the time from electrical contact to tile first phloem specific pattern indicating the time taken to reach and attempt to feed upon the phloem were analysed. As a result, except the number of potential drop, there was no significant differency of feeding patterns among 5 plants. However, the feeding patterns related on host acceptability were observed more frequently from Pepper, radish, and e99r1an1 than melon and cabbage.

• Korean journal of applied entomology
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• v.62 no.3
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• pp.139-147
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• 2023

Leaf-spray in vitro bioassays appraise new aphicidal formulations for managing deleterious plant-feeding aphids. The formulation may utilize alternative and integrated strategies. However, leaf spraying even under controlled conditions may affect aphid reproduction and mortality. This study examines leaf spray applications for optimum and reproducible aphicidal results using tobacco leaves overlaid on cotton fabric or water agar surfaces. Infestation of the undersides of tobacco leaves with nymphs of green peach aphids was used in the assays. Spray distance and volume were optimized using water-sensitive paper to ascertain the best surface coverage. Overlays of the leaves on water agar caused less mortality and greater reproduction than the use of cotton fabric. The relative humidity of the insect-rearing chambers changed with the watering regime for the insect - rearing chambers with cotton fabric; 60% relative humidity was optimal. Relative humidity was not affected by the concentration of agar in the water agar chambers. Applications of the chemical aphicidal standard, Sulfoxaflor, under the optimized conditions exhibited similar times for lethality although the rate was faster with leaves on the cotton fabric than on water agar. These studies establish reproducible and sensitive techniques for assessing the lethality and effects on reproduction of potential aphicidal products.

• Korean journal of applied entomology
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• v.49 no.3
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• pp.261-264
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• 2010

Occurrences of Rhopalosipnum rufiabdominalis damage in the leaves of Japanese apricots were observed in Hadong, Gyeongnam Province, a major producing area. R. rufiabdominalis occurred from early May to mid October, with the peak occurrence of damaged leaves in mid May. To find proper timing of chemical control against R. rufiabdominalis, acetamiprid WP was sprayed weekly from 3 April, before budbreak, to 8 May in 2007. The best time for control R. rufiabdominalis was on 17 April 2007, at which the leaves were still tender and developing up to 3 to 5 leaves.