• Title/Summary/Keyword: 유충 밀도

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Bionomics and a Lana Sampling Method of Coppery Wireworm, Selatosomus puncticollis (Motschulsky), (Coleoptera: Elateridae) in Potato Field (청동방아벌레(Selatosomus puncticollis Motschulsky)의 생태적 특성 및 감자포장내 유충밀도 조사법)

  • Kwon, Min;Park, Cheon-Soo;Lee, Seung-Hwan
    • Korean journal of applied entomology
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    • v.43 no.3 s.136
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    • pp.195-200
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    • 2004
  • The occurrence pattern and bionomics of Selatosomus puncticollis (Motschulsky) were surveyed in three net house (6$\times$70m) in the field and in a laboratory ($20^{\circ}C$, RH$75\%$, L16/DB). Emergence of hibernated adults of S. puncricollis started from early May, reached peak at early June and diminished in late June. Occurrence rate to total number was $42.1\%$ in early June and $31.7\%$ in late May, when most of hibernated adults emerged at these periods. Adults started to oviposit from mid June, and eggs hatched from early July Larvae turned into pupae from mid July and emerged to adults from mid August. Egg-period was 23 days and pupal period was 21 days. It is estimated that preovipositional period and larval period were approximately 10 months and 30 months, respectively. Wireworms were distributed at the soil depth of 10-5 cm, $56.8\%$ in 1997 and $45.8\%$ in 1998. To establish bait techniques to attract wireworms in the soil, six baits: pieces of potato, carrot, and sweet potato, wheat grains, corns, and flour dough wrapped with gauze, were buried at 15 cm of soil depth, and collected after 5 and 10 days. The numbers of wireworms attracted by potato pieces, wheat grains and sweet potato pieces after 10 days were 1.8, 1.6, and 1.4/bait, respectively. Therefore, burying potato pieces at 15 cm of soil depth and collected after 10 days could be recommended as a wireworm baiting technique.

Population Dynamics and Injuries by Liriomyza trifolii(Burgess) in Chrysanthemum Field (국화에서 아메리카잎굴파리(Liriomyza trifolii)의 발생소장, 가해특성과 품종에 따른 피해)

  • 박종대;이호범;김선곤;김도익;박인진;김상철;김규진
    • Korean journal of applied entomology
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    • v.39 no.3
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    • pp.141-147
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    • 2000
  • This study was carried out to investigate the population changes of Liriomyza trijolii (Burgess) on chrysanthemum and its relationship to plant growth and damages. In spring culture of chrysanthemum, L. trifolii adults begun to be attracted by the yellow sticky trap from early May and maintained high population until the middle of July. Larval density increased gradually from late May and reached peak in early July. In autumn culture, the population density of adult was lower than that of spring culture but the number of adult was great in late September and the middle of October. This trend was similar to that of larval stage. Damaged leaves by larva could be found from 4 weeks after transplanting and its rate was low until 5 weeks but increased abruptly after 6 weeks and maintained 70% level until flowering stage in spring culture. Damaged leaves increased with plant growth in some varieties tested in this experiment.

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The Effects of the Application Time of Buprofezin 25% WP on the Density of the Brown Planthopper(Nilaparvata lugens Stal) (Buprofezin 25% WP의 처리시기와 벼멸구(Nilaparvata lugens Stal) 밀도억제효과)

  • 배윤환;이준호;현재선
    • Korean journal of applied entomology
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    • v.31 no.4
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    • pp.551-559
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    • 1992
  • These studies were conducted to investigate the biological effects of buprofezin 25% WP on the adult of the brown planthopper (BPH) and its control effects on the BPH population, when buprofezin was treated on different days after the introduction of the BPH adult to the potted rice. Also age structures of the BPH population at the time of buprofezin treatment were observed. The results were as follows: Buprofezin (7.0 g a.i./l0 a) could reduce the longevity and fecundity of the newly emerged female but did not affect the biology of older female, and it did not affect the biology of the male. The larval densities at the time of buprofezin treatment was reduced to nearly zero after treatment. The higher the residual effect and the proportion of larvae at the time of buprofezin treatment were, the higher its con¬trol effect on the BPH population was. In case of buprofezin 7.0 g a.i./l0a treatment, the time interval of treatment that could show the highest control effect was about 10 days (from 18 days after the adult introduction to the adult emergence days of next generation).

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차주머니나방 "해충안전지대" 침입 - 은행나무 해충 피해실태와 방제대책 - 천적밀도, 자연폐사율 낮아 피해 계속 늘어날듯 유충 대상으로 약제살포 필요

  • 이범영
    • Agrochemical news magazine
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    • v.15 no.6 s.123
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    • pp.70-73
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    • 1994
  • 최근에 들어 서울, 인천등 도시지역에 ''차주머니나방''이 발생하면서 은행나무도 해충에 대하여 안전한 수종이 아니라는 감을 주고 있다. 은행나무의 해충으로 10여종이 알려져 있으나 차주머니나방과 깍지벌레류 이외는 크게 문제되지 않을 것으로 본다.

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White Grubs in Turfgrasses of Golf Courses and Their Seasonal Density (골프장 코스내 잔디 가해 굼벵이 종류와 계절별 밀도)

  • 추호렬;이동운;이상명;권태웅;성영탁;조팔용
    • Asian Journal of Turfgrass Science
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    • v.12 no.3
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    • pp.225-236
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    • 1998
  • The white grubs in turfgrass were investigated from 15 golf clubs in 7 provinces and 2 metropolitan cities. 12 white grub species were collected and 11 species in 8 genera including oriental beetle, Anomala orientalis were identified but 1 species was not identified. The oriental beetle grub was the most serious pest in turfgrass out of them. The brown chafer, Adoretus tenuimaculatus was widely distributed species collected from 6 golf clubs, Maladera castanea was collected from 5 golf clubs and A. orientalis, Holotrichia kiotoensis, and M. orientalis were collected from 4 golf clubs. The white grubs, their density, and distribution depth were also observed at tee, fairway, and green from Yongweon, Daegu, and Dongrae golf clubs. A. orientalis was dominant species in overwintering season but A. tenuimaculatus was dominant one in unoverwintering season. The density of white grubs was low in the green compared with tee or fairway. Distribution depth was different depending on season in Daegu and Dongrae golf clubs but not different in Yongweon golf club. Although there showed no differences in white grub species depending on turfgrass but density was different, that is, A. tenuimaculatus was abundant in Zoysia matrella while A. orientalis abundant in Poa pratensis. The density of A. orientalis grubs was higher in older golf courses but there showed no differences in white grub species depending on the age of golf club.

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Chemical Control of the Pine Gall Midges (Thecodiplosis japonensis Uchida et Inouye) ( I ) -Low-volume Foliar Spray of the Insecticides- (솔잎혹파리의 약제방제에 관한 연구 -고농도미량엽면살포-)

  • Choi S.Y.;Song Y.H.;Lee H.R.
    • Korean journal of applied entomology
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    • v.18 no.2 s.39
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    • pp.111-116
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    • 1979
  • The experiments were carried out to evaluate the effectiveness of some insecticides in the control of the pine gall midges (Thecodiplosis japonensis Uchida et Inouye) when the low-volume of the insecticides were applied by the mist foliar sprayer. The insecticides, Salithion $(24\%\;Ec)$, Omethoate $(Folimat^{(R)}\;50\%\;Ec)$, Monocrotopos $(Azodrin^{(R)}24\%\;Ec)$, Acephate $(Ortran^{(R)}\;50\%\;Wp)$, Metalkamate $(Bux^{(R)}24\%\;Ec)$. BPMC $(Bassae^{(R)}50\%\;Ec)$ and MIPC $(Mipcin\;50\%\;Wp)$ were tested with 100, 200 and 400 times of water solution on the basis of single application at the six different intervals. Salithion was the most effective for the pressure of the gall formation by the pine gall midges and Omethoate, Monocrotophos and Metalkamate were relativey effective and others no effective. The most reliable concentration of the insecticides was 100 times of water solution, and the feasible timing of insecticide application on the basis of single application would be from May 9 to July 1 with Salithion, June 6 with Metalkamate and June 20 with Omethoate and Monocrotophos. The number of pine needles with the larval injured signs (no larvae in the needles) excluded the gall-formed needles were relatively higher in the treatments of Omethoate, Salithion and Monocrotophos than other insecticides. The treatments of Omethoate, Salithion and Monocrotophos caused the lower larval population in the gall than other insecticides.

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Economic Injury Levels for the Common Cutworm, Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) on Soybean (콩 담배거세미나방(Spodoptera litura)의 경제적 피해수준)

  • Lee, Geon-Hwi;Bae, Soon-Do;Kim, Hyun-Joo;Park, Sung-Tae;Choi, Man-Young
    • Korean journal of applied entomology
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    • v.45 no.3 s.144
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    • pp.333-337
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    • 2006
  • The damage aspects of soybean by common cutworm, Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) at different larval density and different growth stage of soybean were studied in soybean field. The percent yield reduction(Y) of soybean infested by different densities of S. litura (X, no. of larvae/plant) under outdoor conditions for a three week period were estimated by the following equations: (1) Y = 1.655X - 6.025 ($R^{2}=0.952$) for the R1 (flowering stage); (2) Y = 0.725X - 0.475 ($R^{2}=0.986$) for the R3 (beginning pod stage); and (3) Y = 0.635X - 1.325 ($R^{2}=0.986$) for the R5 (beginning seed stage). Based on the relationships between the densities of S. litura larvae and the yield index of soybean, the number of larvae (2nd-3rd instar) which caused 5% loss of yield (Tolerable injury level) was estimated to as approximately 6.7 for the R1, 7.5 for the R5, and 10.0 per plant for the R5, respectively. Average soybean leaf areas consumed by 1st, 2nd, 3rd, 4th, 5th and 6th larvae of Spodoptera litura during 24 hr at $28^{\circ}C$ was 0.3, 0.7, 2.6, 4.0, 20.1, and $55.8\;cm^{2}$, respectively.

Occurrence and Vertical Distribution of Meloidogyne incognita in Chinese Yam (Dioscorea batatas) (마 재배지의 뿌리혹선충의 발생 실태 및 수직 분포)

  • Kwon, Giyoon;Kang, Heonil;Seo, Jongmin;Yun, Eulsoo;Park, Namsook;Choi, Insoo
    • Research in Plant Disease
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    • v.25 no.3
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    • pp.124-130
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    • 2019
  • The study was conducted to investigate the infestation and distribution of plant-parasitic nematodes on Chinese yam (Dioscorea batatas) in Andong, Korea. Root-knot nematodes, Meloidogyne incognita was the most prevalent nematode species which is found from 43 yam fields (81.1%) with high population densities (average of 450 juveniles/$300cm^3$). Other nematodes, root-lesion nematode (Pratylenchus spp.) and pin nematode (Paratylenchus spp.) were less problematic. Density of juveniles (J2) of M. incognita was $10\;J2/300cm^3$ by August, then increased to 274 in September and 624 in October. The highest J2 density was found at the soil depth between 40 and 50 cm ($1,840\;J2/300cm^3$). M. incognita was able to infest yam tuber down to a depth of 70 cm and developed galls outside and brown spots inside. The highest number of females were found at 40-50 cm (79 females/10 cm piece) tuber from the top.

Development of Collection Method of Arboreal Parasite Larvae for the Biological Control against Pine Needle Gall Midge, Thecodiplosis japonensis Uchida et Inouye (기생봉사육용(寄生蜂飼育用) 솔잎혹파리 유충채집(幼蟲採集)에 관(關)한 연구(硏究))

  • Chung, Sang Bae;Kim, Chul Soo
    • Journal of Korean Society of Forest Science
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    • v.86 no.3
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    • pp.334-341
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    • 1997
  • Artificial precipitation test with sprinkler system was carried out to develop the collection method of arboreal larvae(proctotrupoid wasps) of pine needle gall midge for biological control in 1995. Effects of larvae falling on each amount of precipitation, season of precipitation and time of precipitation of a day following artificial precipitation were examined during the period of larvae falling season. The results obtained were summarized as follows; 1. Artificial precipitation with sprinkler system was highly effective for collection of pine needle gall midge larvae and the most suitable amount of precipitation was 5.3-9.4mm; application amount and hours of water were $8,000-16.000{\ell}$ and 180-360 minutes, respectively. 2. The most effective period of larvae collection for artificial precipitation was approximately 20 days, from early through mid November, and larvae falling was 93.4% of the total number of larvae collection during this period. 3. Larvae falling from the tree crown was not affected by the artificial precipitation for the precipitation hour intervals in a day. 4. The percentage of parasitism of collected larvae of pine needle gall midge in November exceeded that of December but was not significantly different between two seasons. 5. Artificial precipitation of sprinkler system was effective in reducing 34% of gall formation after one year at collected sites of pine needle gall midge larvae. 6. The collection method of larvae following artificial precipitation was effective in reducing the expenses by 14-50% than that of collection method of infested needles.

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