• Korean Journal of Agricultural Science
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• v.13 no.2
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• pp.176-184
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• 1986

A biological study was done on primary parasites and hyperparasites of green peach aphid, Myzus persicae, collected in Taejeon area during the period from April to September 1985 was. The results of mummification of primary parasites, host selectivity between primary parasites and hyperparasites, and longevity of important species were obtained as follows; 1. Among the 201 mummies collected in the field, adult primary parasites and adult hyperparasites were 38.3% and 44.3%, respectively. 2. Among the primary parasites, Lysiphlebia japonica and Trioxys hokkaidensis were most important species. 3. Among the hyperparasites, Prataphelinus nikalskajae, Eucoila sp. and Ardiles convexa were dominant species. 4. L. japonica was more parasitized by the hyperparasites than T. hokkaidensis. 5. T. hokkaidensis was higher than L. japonica in the ability of parasitism. 6. L. japonica had lived for 3 days by feeding glucose, the other foods had lived shorter than food.

• Korean journal of applied entomology
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• v.39 no.4
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• pp.251-258
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• 2000

These studies were conducted to investigate the prey consumption and suppression of cotton aphid and green peach aphid by Chrysopa pallens Ramber as a predator. The 3$^{rd}$ instar of C. pallets fed on 29.8, 77.9, 133.6, and 155.7 individuals of apterous Aphis goussypii Glover a day at 17,22, 27, and 32$^{\circ}C$, respectively. A preovipositing female fed on 73.1 individuals, ovipositing female on 86.6 individuals, and adult male on 69.7 individuals of apterous Myzus persicae (Sulzer) a day at the 27$^{\circ}C$. The functional response curve of the larvae and adults of C. pallens to the densities of A. gossypii indicated Helling’s Type II: the consumption of prey by the C. pallens increased with the prey density but the consumption rate decreased. The attack rate of 3rd instar of C. pallens was the highest among the 2nd instar, 3$^{rd}$ instar, adult male and adult female, and handling time was the shortest. The critical ratio of the predator vs. the prey to effectively suppress the population of A. gossypii by releasing C. pallets eggs was 1 : 4 on red pepper and egg plant, and 1 : 3 on cucumber. Release of second larval stave of C. pallens at the ratio of 1 : 30 of the predator vs. the prey controlled satisfactorily A. gossypii on red pepper, and 1 : 20 on cucumber and tomato. The three-times introduction of the eggs of C. pallens was as effective as four applications of insecticides from mid-June to late September.r.

• 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.16 no.3 s.32
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• pp.139-144
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• 1977

The green peach aphid Myzus persicae(Sulzer), is known as the most important vector of potato leaf-roll virus and PVY. Yield of potato plants infested with these viruses are remarkably lower than non-infested plants. A study was conducted to investigate the life history of the green peach aphid at Suweon, Korea (Lat. $37^{\circ}$'N., Long. $126^{\circ}59$'E). The following were obtained: 1. Overwintering eggs hatched from late March to early April, with a hatching rate averaging ninety-five percent. 2. The fundatrigeniae leave the primary host(Punus persica) in early to mid May and migrate to the secondary hosts. 3. From mid to late Oct., the gymnoparae migrate from the secondary hosts to the primary hosts. 4. From early to mid Nov., gymnoparae lay fertilized eggs around buds, in bark crevices, or between bifurcated twigs of the primary hosts. 5. The early-born progeny have 23 generations and the late-born progeny have 9 generations on peach trees, potatoes and raddish from Apr. to Oct. 6. The average length of life was about 28.5 days, with a developmental period of approximate 10.8 days and a reproductive period of 15.8 days. 7. The average number of nymphs produced by a female was fifty, with a maximum number of 118. 8. The average number of nymphs produced by a female per day was about 3.2, with a maximum number of 13.

• Korean journal of applied entomology
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• v.7
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• pp.5-13
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• 1969

Present system of seed potato production in Korea has several weak points and consequently has difficulties in covering annual shortage of 60,000 tons of seed potatoes. The author has an opinion that this so called 'High land system' of seed potato production adopted by the Government should be replaced by the 'Coastal area system' which is proposed by the author and has many advantages over present 'High land system'(2). In coastal areas where enormous acreage of rice paddies are spread, mostly around the villages. the primary host plants of the vectors are found. Therefore, the only source of aphid vectors are limited to the villages. The farmer's houses scattered more sparsely also have minor importance. In the previous paper(2), the author reported that the aphid vector populations were lower in the coastalareas than at Taegwanryong where the Alpine Experiment Station for the production. of seed potatoes is located. However, the number to vectors at Okku showed rather high density, where the trap was placed at the distance of 200 m from a village where peach and Hibiscus trees, the primary hosts of Myzus pesrsicae and Aphis gossypii were grown. To clarify the flight distance from the source of the aphid vectors, a trial was carried out in the Kwanghwal area, Kimje-gun, Cholla-pukto. on the western coast. 13 traps were placed at four directions and the distances between the traps were 250 m. (Fig. I) The traps 'Were operated from June 21 to October 31. The results are shown in Table 1. A total of some 70 species of aphids were found, including 5 speceis of potato virus vectors. The vectors are as follows: I. Myzus persicae (Sulzer) 2. Aphis gossypii Glover 3. Aulacorthum solani (Kaltenbach) 4. Lipaphis erysimi (Kaltenbach) 5. Macrosiphoniella sanborni (Gillette) Out of a total of 12,797 aphids, 5,187$(48\%)$ vectors were found. The trap catches at the 13 locations are shown in Fig. 2 and the numbers of the vectors at each location for each vector, except Macro-siphoniella sanborni. of which only a single individual was caught, are shown in Fig. 3-6. Number of vectors at C (3,279) (Centre of the village) is considerably higher than that at Suwon (763); however, EI. SI. WI and NI. where the distanecs from Care 250 m, showed lower numbers of vectors than that at Taegwanryong (347). The number of vectors at NI was rather than at the other 3 locations at the distance of 250m from the village. This was because C was in the southern part of the village. Consequently NI was much closer to the village than the other 3 locations of the same distance from C. Numbers of catches of the most important vector. Myzus persicae, are shown in Fig.3. The distribution pattern is typical except $S-2\;and\;W_3$, where several farmer's houses were found. If only the rice paddies were found in these locations. the numbers of the vectors would be small as the distances increase. Numbers of catches of the other 3 vectors are shown in Fig. 4-6. From these results. the author has drawn the following conclusions: 1. The aphid vector sources at the rice paddy belt in the western coast are the villages. 2. The vector densities at the locations where the distances are 250 m from the centre of the village are lower than that at Taegwanryong. 3. The vector densities become gradually lower as the distances from the centre of village increase. However. depending on the host plant situation at each location, the vector densities are variable. These minor sources of aphid vectors may be eliminated so that seed potatoes can be grown. 4. Thus. under the direction of specialists, fields suitable for seed potato production can be found in the coastal areas.

• Journal of the Korean Chemical Society
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• v.10 no.2
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• pp.62-66
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• 1966

An insecticide was obtained from condensation of chloral hydrate with 2,4,5-trichloro phenol. The structure of the insecticide was found to be 5,6,8-trichloro 2,4-di-trichloro methyl benzo 1,3-dioxane. The best conditions of the condensation were as follows: 1) The sulfuric acid concentration; $97{\%}$. 2) The mole ratio of sulfuric acid to 2,4,5-trichloro phenol; 14.2. 3)The mole ratio of chloral hydrate to 2,4,5-trichloro phenol; 2.4. 4) The reaction time & reaction temperature;15hrs & $50-55^{\circ}C$.The insecticidal effects of T. D. B against the Citrus Red Mite and Green Peach Aphid were the same of Mydran.

• The Korean Journal of Pesticide Science
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• v.13 no.2
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• pp.117-125
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• 2009

Phenylformamidine derivatives are well known as insecticides for their specific activity against the insects. It has now been established that they show insecticidal activity as agonists on the octopamine receptor which is located in the synapse membrane. The reaction of triethylorthoformate and fluoroanilines gave formimidates (1) in good yields and N',N'-Disubstituted N-fluorophenylformamidine derivatives were synthesized more easily by using microwave. This microwave reaction condition gave products in high yields and faster reaction time than conventional methods. All the compounds were screened for their biological activity agaist harmful insects of plant hoppers, moths, aphids and mites. Synthetic compounds of 2-I-a, 2-I-c, 2-I-d, 2-II-d showed good activity against mites and plant hoppers.