피망 작물에서 점박이응애 및 칠레이리응애의 수직 분포 및 확산 정도를 알아보고, 주간 브릿지를 이용한 칠레이리응애의 확산을 조사하였다. 이들의 확산은 점박이응애의 접종 밀도 및 위치에 따라 달랐다. 점박이응애를 상위엽에 주당 10 마리 접종하였을 경우 방사 5일까지도 하위엽보다는 상위엽에 머무는 경향을 보였으며, 주당 100 마리를 접종했을 때 이미 방사 1일차에 하위엽까지 이동하였다. 반면에 하위엽에 주당 10 마리 접종 후 1일차에 중·상위엽으로 이동하였고, 3일차는 상위엽에만 존재하였다. 주당 100 마리를 접종한 경우 접종 1일차에 상위엽까지 이동하였으며 시간이 경과함에 따라 하위엽보다는 상위엽에 더 많이 분포하는 경향을 보였다. 점박이응애를 접종한 이후 칠레이리응애의 접종 위치에 따라 이들이 확산되는 정도를 조사한 결과, 점박이응애가 없을 경우 칠레이리응애를 하위엽에 방사하여도 상위엽으로 이동하였고, 상위엽에 방사하면 방사 후 3일까지 는 상위엽에 머물러 있었다. 점박이응애가 있을 경우 칠레이리응애는 방사 이후 먹이가 있는 곳으로 이동하는 경향을 보였다. 피망 세개 주를 상부 또는 하부에 실로 연결하고, 2, 3번 작물에 점박이응애를 접종한 후 1번 작물의 상·하위엽에 각각 칠레이리응애를 방사하였을 경우 연결된 실을 통해 이웃 작물로 이동하였다. 따라서 방사되는 칠레이리응애의 확산을 증진하기 위해서 가능하다면 작물체 간격을 좁혀주거나 작물체를 인위적으로 연결하여 준다면 더 넓은 지역으로 확산 가능하여 방사된 칠레이리응애에 의한 점박이응애 방제효과도 크게 증진될 수 있을 것으로 판단된다.

This study was conducted aiming to figure out two things. First, knowledge of the change in spatial distribution of Tetranychus urticae depending on how to control it (using pesticide or natural enemy). Second, spatial association of T. urticae and Phytoseiulus persimilis in biocontrol plot (B.P). The data was analyzed by spatial analysis by distance indices (SADIE) using global aggregation index, Ia . Ia values were 0.77-1.37 in conventional plot (C.P) and 0.88-1.68 in B.P, respectively. However, the fluctuation level of Ia in B.P was higher than C.P. Therefore, the results indicated that there was a clear spatial pattern change in B.P, i.e. prey’s spatial distribution is affected by natural enemy. And spatial association analysis showed that T. urticae and P. persimilis have positively associated. It means that T. urticae is relatively low mobile prey, and P. persimilis is relatively high mobile predator.

The two-spotted spider mite, Tetranychus urticae Koch (TSSM)(Acari: Tetranychidae) is the major arthropod pest in strawberry greenhouses. Elevated levels of stress caused by high populations of TSSM can lead to a significant reduction in vegetative growth and flower development, which can decrease the quality and quantity of mature fruits. Currently, TSSM is managed by pesticide, and which makes that is distributed all over the world with various pesticide resistances and environmental side effects. To solve these problems, alternative pest management strategies are being tried. Biological control, one of alternative strategies, is relatively low toxicity and stable to agricultural ecosystems. I compared the density of TSSM in export strawberry greenhouses, those are under conventional pesticides and natural enemy applied, respectively, and also evaluated the cost of management of each control strategy.

국립수목원 열대식물자원연구센터내에서 생육중인 열대관상 식물인 Acalypha wilkesiana에 발생하여 피해를 주고 있는 점박이응애(Tetranychus urticae)의 생물학적 방제를 위해서 칠레이리응애(Phytoseiulus persimilis)를 방사한 후 8주간 매 1주일 간격으로 점박이응애의 밀도변화를 조사하였다. 칠레이리응애는 점박이응애 발생 지점에 300개체/m2의 밀도로 방사하였다. 방사 후 1주차에는 점박이응애의 상대밀도가 다소 증가하였으나 2주차에는 최초 밀도대비 64%수준으로 4주차에는 16%수준으로 5주차 이후에는 2%수준으로 줄어들었다. 식물원의 특성상 해충 발생지점이 구획화 되어있기 때문에 점박이응애의 조기발견 후 천적 투입량의 밀도를 조절할 경우 2주차 정도의 시간이면 방제효과의 가시적인 관찰이 가능한 것으로 나타났다.

Strawberry, Fragaria ananassa Duchesne, is one of the important horticultural crops cultivated in greenhouses. Tetranychus urticae is one of major strawberry pests, and Neoseiulus californicus and Phytoseiulus persimilis have been used as biological control agents for control of T. urticae. The interactions between T. urticae and N. californicus and between T. urticae and P. persimilis were investigated to compare their control efficiency for T. urticae on a spatially-structured strawberry leaf disc area at different temperatures and on different treatments. The experimental arena was an array of leaf discs (3 cm diameter) placed upside down on a water-saturated cotton pad in an aluminum pan (17.4 x 21.5 cm). Twenty leaf discs (4 x 5) were placed adjacent each other for allowing dispersal of T. urticae and its predatory mites. The temperature conditions were 20, 25, and 30°C and there were six different treatments. The overall population densities of T. urticae were influenced by temperature (20, 25, and 30°C) in N. californicus treatment. In the same temperature condition, P.persimilis was more effective than N. californicus to control T. uritcae. Two predator systems were better than one predator systems to suppress the population density of T. urticae at 25°C. Some results of this study could be used to understand the spatial association of T. urticae and its predatory mites in greenhouse crops and fields.

We have investigated some biological characteristics, such as survival rate and fecundity, of Orius laevigatus and Phytoseiulus persimilis, which have been stored at 6, 8, 10, 12±1℃, RH 70±10%, in dark condition. Overall, an appropriate temperature for cold storage was 10℃ for O. laevigatus and 8℃ for P. persimilis. 70% of adult O. laevigatus could survive for 36 days at 10℃. The O. laevigatus stored at 10℃ for 10~50 days laid 37.1～120.5 eggs. Since fresh (no storage) O. laevigatus laid 224.5 eggs, comparative fecundity of stored adults was 16.5~53.7% of normal fecundity. P. persimilis stored at 8℃ for 7~42 days with (food eggs of Tetranychus urticae) laid 11.9～18.9 eggs. Since fresh P. persimilis laid 26.4 eggs, comparative fecundity of stored adults was 45.1~71.6% of normal fecundity.

The two-spotted spider mite, Tetranychus urticae Koch, is one of major pests in greenhouse strawberry. Two predator mites, Neoseiulus californicus (McGregor) and Phytoseiulus persimilis (Athias-Henriot), have been widely used for control of T. urticae because they have good functional and numerical responses and searching behaviors. The study of single species releasing and combined releasing of two predatory mites, N. californicus and P. persimilis, was conducted on connected strawberry leaves. The experiments were run under laboratory conditions, 24±1oC, 50-65% RH, and a photoperiod of 16:8 (L:D) h. The excised leaf disk (diameter 3cm) of two strawberry varieties – Maehyang, Sulhyang– were placed upside down on a water-saturated cotton pad in an aluminum pan (width × length 17.4 × 21.5 cm). Twenty leaf disks were placed on each experimental set and the disks (width × length 4×5 cm.) were connected with each other for dispersing of T. urticae and its predatory mite. There were four different experiments – two strawberry varieties and two treatments (releasing single predatory mite, releasing two predator mites). The experiment sets were covered with plastic cage to protect from invading other insects and mites. All life stages of T. urticae and predatory mites were recorded until all mites were vanished. The data were transformed by ln (x+1). Repeated-measures analysis of variance was used to compare the temporal variation in the overall T. urticae and predatory mite density. The average number of T. urticae per leaf arena was significantly different among treatments in Sulhyang (Treatment, df=3, 196, F=17.86, P=0.0001; Time, df=6, 1176, F=47.76, P=0.0001; Time ×Treatment, df=18, 1176, F=22.06, P=0.0001) and in Maehyang (Treatment, df=3, 196, F=42.07, P=0.0001; Time, df=6, 1176, F=64.51, P=0.0001; Time x Treatment, df=18, 1176, F=24.19, P=0.0001). When N. californicus was introduced to P. persimilis system with diminishing prey, P. persimilis population increased more rapidly than N. alifornicus but P. persimilis was displaced by N. californicus. In single or combined releasing system, N. californicus persisted longer after prey depletion than P. persimilis. We examined population growth of P. persimilis and N. californicus in single and combined predatory mite released system with diminishing prey.

Environmental tolerance of three important spider mite predators; Neoseiulus womersleyi, Neoseiulus californicus and Phytoseiulus persimilis (Phytoseiidae) was experimented by treating combination of temperature and relative humidity for egg hatching and immature survival. Egg hatching rate increased at the relative humidity incrased for three species. Temperature effects were only significant to N. californicus and P. persimilis. The lethal humidities for three species were in the range of 56-77, 82.0, 66-94% RH, respectively. Larva does not need to feed for larval development into protonymph in three tested species. No larvae survived at lower than 75% RH for N. womersleyi, but around 80% at 95% RH. N. californicus larvae survived around 50% and 100% at 75 and 95% RH. P. persimilis larve survival was decreased as the temperature increased at 75% RH, but platued around 100% at 95% RH. Cannibalism was higher in N. californicus and lower in P. persimilis. Implementation of the results was discussed relative to biological control of spider mites in open field and greenhouse crops.

Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseidae) is well known as an effective natural enemy of two-spotted spider mite, Tetrnychus urticae Koch (Acari: Tetranychidae). However, successful biological control usually requires adequate management of temperature. While P. persimilis did suppress T. urticae at moderate condition (20~25oC) in a week or so, the density of P. persimilis was barely increased at cold condition (5~10oC) in three weeks or so. The problem is that winter temperature is too cold for the development and reproduction of P. persimilis in greenhouse for forcing strawberry. Night temperatures in greenhouse were even mostly lower than 6oC. So, winter application of P. persimilis against T. urticae is useless. To avoid damage from T. urticae in early spring season, it was better that the release amount of P. persimilis was double at middle- and late-October, instead of early-November to next early-February. If necessary, the double releasing of P. persimilis might be good for control of T. urticae at middle- and late-February.

Temperature and humidity are the vital environmental factors influencing the distribution and abundance of ectothermal organisms. Also, these variables often determine the efficacy of biological control of spider mites using phytoseiid mites N. californicus, N. womersleyi and P. persimilis are promising biocontrol agents of spider mites. The combined effects of temperatures (15,20,25,30 & 35oC) and relative humidity (33,51,75 & 95%) on egg hatch, incubation period from single egg and cannibalism from five eggs experiment were tested for three phytoseiid mites. Photoperiod was set to 16L:8D and neither water nor diet was provided. The result showed that higher temperatures (30&35oC) and lower relative humidity (33&51%) caused increased egg mortality by shrinking and desiccation. The egg hatch of N. californicus and P. persimilis were higher than N. womersleyi in all conditions with the exception of 35oC and 95% RH treatment where P. persimilis did not hatch at all. The incubation periods of egg decreased as the humidity level increased even under the same temperature. The cannibalism, habit of feeding the same species was found from protonymphal and deutonymphal stages under higher humidity levels (75&95%) in the three phytoseiid species. This tendency was higher in N. californicus and N. womersleyi than in P. persimilis. The results partially explain the lower predator performance during hot summer by P. persimilis and the possibility to sustain the predator population when the prey population is low.

Many kinds of environment friendly agricultural materials were used for the insect pest control and the control of plant diseases, furthermore they support the growth of crops in the greenhouses and the kindly environment friendly farming. Phytoseiulus persimilis might be used for control of two-spotted mites with environment friendly agricultural materials at the same time. For testing the toxicity of environment friendly agricultural materials against to P. persimilis, 61 environment friendly agricultural materials were selected by material contents and using methods. When environment friendly agricultural materials were directly sprayed on P. persimilis, IEFAM C, FEFAM A, EFAMSM A, D, EFAMPE A, EFAMCh B, EFAMME A, and EFAMMo C killed over 90%. However, there was no effects to FEFAM C, D, EFAMSM C, EFAML A, EFAMME C, E, H, J, EFAMMo G and I against P. persimilis. P. persimilis adults were not survived in vial for 48 hours after sprayed and dried with the environment friendly agricultural materials, for examples, EFAMSM I, EFAMME A, EFAMMo A, C, and I. Otherwise, EFAMCh C and EFAMMo B were no effects to P. persimilis. Some environment friendly agricultural materials are of different qualities, and consequently test of their toxity have to necessary.

Biological control of Tetranychus urticae by Phytoseiulus persimilis was observed in eggplant greenhouse for spring and autumn season culture. Tetranychus urticae was controlled to low density of less than 1 mite from June 24 after P. persimilis were released 3 times at rate of 10 per plant on June 1, 11, and 18, 2004 in spring season experiment. The population of Tetranychus urticae was also less than 1 mite per eggplant leaf from September 1 to October 22 after three times releases of 10 P. persimilis in autumn season experiment. In Phytoseiulus persimilis released plot, the percentage of leaves with T. urticae adults and nymphs were 8.6~13.3% and 5% or less in spring and autumn season experiment. The density of T. urticae was from 1 to 2 on leaves with T. urticae adults and nymphs.

장미의 병해충 방제에 등록되어 있는 34종, 등록되어 있지 않은 5종, 그리고 보조제 3종, 충 42종의 농약에 대한 칠레이리응애(알, 약충, 성충)와 점박이응애(알, 성충)의 선택독성과 칠레이리 응애에 의한 점박이응애 밀도억제효과를 조사하였다. 살비제 중 acequinocyl, bifenazate, fenbutatin oxide, spirodiclofen은 칠레이리응애에 대해서 독성이 낮았으나, 점박이응애에 대해서는 독성이 높았다. 살충제는 acetamiprid, imidacloprid, spinosad, thiamethoxam, acetamiprid＋etofenprox가 칠레이리응애와 점박이응애에 대해서 독성이 없거나 적었다. 살균제 중에는 azoxystrobin, kresoximmethyl, myclobutanil, nuarimol, triadimefon, triflumizole, oxadixyl＋mancozeb이 칠레이리응애와 점박이응애에 대해서 영향이 없었다. 농약보조제인 cover와 siloxane은 칠레이리응애에 대해서 독성이 컸으나, spreader는 영향이 없었고, 점박이응애에 대해서는 독성이 없거나 낮았다. 장미시설하우스에 서 칠레이리응애에 의한 점박이응애 밀도억제효과를 조사하기 위하여, 점박이응애의 밀도가 잎당 65.3마리였을 때, 칠레이리응애를 주당 30마리 방사하였다. 방사 후 11일에 점박이응애 밀도가 잎당 3.8마리로 크게 감소하였고, 방사 후 20일에는 잎당 0마리로 밀도억제효과가 높게 나타났다. 조사기간 동안 흰가루병 방제로 살균제 4회(kresoxim-methyl, myclobutanil, nuarimol, triflumizole)와 총채벌레 방제약제를 1회(spinosad)처리하였으나, 칠레이리응애 밀도에는 영향이 없었다. 이상의 결과로 보아 장미 병해충의 종합관리체계에서 칠레이리응애에 독성이 적은 약제와 칠레이리응애를 함께 이용할 수 있을 것이다. controllability. Based upon these results, it is recommended that the developing nursing interventions to change causal attribution and self-efficacy is necessary. A number of theoretical relationships and empirical finding are confirmed by this data, and future proposals in research is suggested. 따라서 교사들의 관심유형과 실행수준에 따라 수행평가에 대한 지원을 달리함으로써 교사들의 관심도와 실행수준을 향상시켜야 할 것이며 보다 효과적인 수행평가가 실시되도록 해야 할 것이다.. 결론적으로 현재 우리나라에서는 갈색 정도의 차이 문제이지 갈색란을 좋아함을 알 수 있었고, 교육에 의해 조금씩은 고정 관념을 바꿀 수 있는 가능성을 확인할 수 있었다.ique impact at 0.70 km/s and 0.91 km/s were compared with experimental results and Eulerian hydrocode CTH simulation results. The Lagrangian code NET3D is superior to Eulerian code CTH in the computational accuracy. Agreement with the experimentally obtained final deformed cross-sections of the projectile is excellent. (3) Agreement with the experimental ballistic limit data, particularly at the high-obliquity impacts, is reasonably good. (4) The simulation result

날개가 없는 몇몇 절지동물들은 공중이동을 하기 위한 수단으로써 이륙행동 보이는 종들이 있다. 본고는 포식성 이리응애류중에서 이륙행동을 보이는 종(Neoseiulus fallacis (Carman)) 과 이륙행동은 보이지 않으나, 공중이동률이 높은 종(Phytoseiulus persimilis Athias-Henriot),이륙행동이 없고 공중이동률이 중간치인 종(N. ca1ifornicus(McGregor))간에 공기역학적 측면에서 어떠한 메커니즘이 작용하는 지에 관한 연구이다. 위 종들의 도보이동 자세와 공주 이동 이륙행동 자세의 몸체의 수직적 위치, 몸체의 크기, 다리의 길이 등의 자료를 가지고 공기역학적 파라미터를 계산한 결과, P. persimilis는 도보이동 자세에서도 N. fallacis가 이륙행동을 보여야만 얻을 수 있는 양의 항력을 얻을 수 있음이 밝혀졌다. 이러한 관점에서 포식성 이리응애류의 이륙행동 진화에 대한 고찰하였다.

칠레이리응애(Phytoseiulus persimilis)의 방사에 의한 차응애(Tetranychus kanzawai)의 방제효과를 비닐하우스 재배 신선초(Angelica utilis)에서 조사하였다. 칠레이리응애 약성충을 7월 23일 당 25마리 방사했을 때 피해잎 4당 차응애 밀도는 7월 22일 25마리에서 9월 9일 0.4마리로 감소했으나 다시 10월 16일에는 9.3마리로 증가했다. 차응애의 밀도는 8월 13일로부터 10월 1일까지 낮았다.

The differential susceptibility of the two spotted spider mite, Tetranychus urticae and its predator, Phytoseiulus persimilis against extracts of Gleditsia japonica var. koraiensis, Camellia sinensis, Cinnamomum cassia, Lantana camara and their mixtures was evaluated. The plant extracts tested were much less toxic to P. persimilis than to T. urticae. The plant extracts tested had little effect on the survival of P. persimilis adult females. Moreover, reproduction of P. persimilis adult females and eclosion of eggs deposited by treated predators were not seriously affected. The treatments of the plant extracts tested showed no serious toxic effect on P. persimilis eggs and exhibited 84∼100% hatchability. The treatments with mixtures 3 and 1 were effective against the adult females of T. urticae and yielded 76.0% and 72.7% adulticidal activity at 7 days after treatment, respectively. The treatment of mixture 2 revealed 63.3% adulticidal activity. Generally, the acaricidal activity of the individual treatment of each plant extract was lower than the mixtures. The adult females of T. urticae treated with mixtures 3 and 1 produced only 29.5∼31.3% as many eggs as the control females did. All the plant extracts tested exhibited no noticeable toxic effect to the eggs of T. urticae. These results suggest that mixtures 3 and 1 might be used for the control of T. urticae, and expected to be promising candidates for use in integrated mite management program with P. persimilis.

The susceptibility of the twospotted spider mite, Tetranychus urticae and the predatory mite, Phytoseiulus persimilis to extracts of Melia azedarach, Piper nigrum, Syringa velutina and their mixtures was evaluated in laboratory bioassays. Treatments of mixture 1 and 2 were effective against adult females of T. urticae and yielded 73.3 and 70.7% adulticidal activity at 7 days after treatment, respectively. Treatment of mixture 3 revealed 62.7% adulticidal activity. However, M. azedarach, P. nigrum and S. velutina had lower adulticidal activity than the other treatments. Adult females of T. urticae treated with mixture 1 and 2 produced only 11.1-16.7% as many eggs as control females did. All the plant extracts tested were ineffective to against the eggs of T. urticae. Plant extracts tested had little effect on the survival of P. persimilis adult females. Moreover, reproduction of P. persimilis adult females and eclosion of eggs deposited by treated predators were not seriously affected. Treatment of plant extracts tested showed no toxic effect on P. persimilis eggs and produced 100% hatchability. These results suggest that mixture 1 and 2 might be used for the control of T. urticae, and expected to be promising candidates for use in integrated mite management program with P. persimilis.