The series compounds from natural products are an effective repellent and deterrent against various kinds of pests. In this study, we evaluated the spatial repellency of fifteen compounds from natural products on the two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), in the laboratory and field by using two-choice and no-choice bioassays. In laboratory two-choice tests, six compounds displayed active spatial repellency against female adult mites at a 2mg dose. The repellency of each compound was also as effective as the 6-compound blend. Three of the six compounds showed the predominant repellent activity (over 90%) that lasted for at least 3 days in laboratory no-choice tests. In a field test, we found that the number of T. urticae was fewer in strawberry seeding treated lure with 2mg of these compounds than in strawberry seeding treated lure with solvent control. Given that the findings are efficacious, economical, and natural products, they can be used in the sustainable management of T. urticae in greenhouse.

환경친화적 생물적방제를 위해 수출딸기온실에서 해충인 점박이응애 밀도 감소 효율을 화학적방제와 생물적방제로 나누어 동일한 크기의 동일한 온실에서 각각 비교하였다. 생물적방제 온실은 점박이응애의 천적인 칠레이리응 애만을 이용하였고, 화학적방제 온실은 일반 화학합성 농약을 이용하여 점박이응애의 밀도를 조절하였다. 화학적방제 온실에 비해 생물적방제 온실에서 점박이응애 모든 태의 밀도가 낮게 관찰되었으며, 생물적방제를 위한 비용이 화학적방제에 비해 낮았다. 이러한 결과는 수출딸기의 주요해충인 점박이응애의 방제에 칠레이리응애를 이용한 생물적방제가 가능한 것을 나타내고 있다.

본 실험은 삼채에 발생하는 점박이응애의 효율적인 약제방제전략의 기초 자료를 확보하고자 시판되고 있는 10종의 살비제에 대해 약제감 수성과 포장 방제효과를 평가하였다. 점박이응애 암컷 성충에 대한 실내감수성 평가 결과 Abamectin EC, Pyflubumide SC, Cyenopyrafen SC, Acequinocyl SC가 100%의 살비효과를 나타내었고, Pyflubumide SC, Acequinocyl SC, Etoxazole SC는 부화율이 0%로 나타나 100% 의 살란효과를 나타내었다. 실내감수성 평가에서 살비효과가 우수했던 Abamectin EC, Pyflubumide SC, Cyenopyrafen SC, Cyflumetofen SC, Acequinocyl SC를 대상으로 포장검정을 평가한 결과, 약제처리 7일차에서 모든 처리구는 90.3% 이상의 방제가를 나타내었다.

Miticidal and repellent activity of twenty plant essential oils against the adults of two spotted spider mites, Tetranychus urticae, were examined. Sandalwood oil was the most potent one in mortality, whereas clary sage oil exhibited the greatest repellent activity. On those twenty essential oils tested, no apparent correlation between toxicity and repellency was observed. The chemical compositions of sandalwood and clary sage oils were identified via GC/MS analyses. The major constituents of sandalwood oils were sesquiterpene compounds, whereas the major ones for clary sage oil were monoterpenes. Among the major components in clary sage oil, linalyl acetate was not only the most abundant constituent, but also the most responsible one for its repellent activity against the adults of the two spotted spider mites. Nevertheless, the combination of seven major constituents of clary sage oil showed lesser repellent activity than the original essential oil did, implying the presence of interactions between the major and minor constituents affecting the overall repellent activity of the crude oil.

본 연구에서는, 20종의 식물정유를 이용하여 점박이응애 성충에 대한 살비활성 및 기피활성을 확인하였다. 살비활성 평가에서는 샌달우드 오일이, 기피활성 평가에서는 클라리 세이지 오일이 가장 높은 효과를 나타내었고, 평가에 사용한 20종의 식물정유간에는 살비활성과 기피활성간 의 상관관계가 매우 낮게 나타났다. 높은 활성을 나타낸 정유들의 혼합시험에서는, 거의 대부분의 조합이 서로간에 저해효과를 갖는 것으로 확인되었다. 샌달우드 및 클라리 세이지 오일의 구성성분은 GC/MS 분석을 통해 확인하였으며, 샌달우드는 세스퀴터펜류가, 클라리 세이지 오일은 모노 터펜류가 주종을 이루었다. 클라리세이지 오일의 구성성분 중에서는 linalyl acetate가 가장 높은 함량을 갖고 있을 뿐만 아니라, 해당정유가 기피효과를 갖는 주된 효능물질임을 확인하였다.

In the preceding symposium, we presented the result of the phylogenetic analysis of Stigmaeopsis spider mites (Acari: Tetranychidae) in Japan using sequence data of the Cytochrome Oxidase subunit I (COI) region of mitochondria DNA. We analyzed haplotypes representing S. longus, S. celarius, S. takahashii and S. saharai, which inhabit bamboo species of the genera Sasa and Phyllostachys (Poaceae; Bambusoideae), and two forms of S. miscanthi (HG and LW) living on Miscanthus sinensis (Poaceae; Panicoideae). Both neighborjoining and maximum-likelihood methods revealed that Stigmaeopsis consists of seven monophyletic groups, in which two forms of S. miscanthi form two distinct monophyletic groups, whereas four species of bamboo-inhabiting species comprise a polyphyletic assembly. These results imply a mismatch between diagnostic morphological characters (i.e. the length of dorsal setae) and their phylogenetic lineages for bamboo-inhabiting species, requiring re-evaluation of the use of these characters. In addition, our results indicate that plural lineages coexist in a single habitat at various regions, suggesting that differentiated lineages secondarily encounter around southwestern Japan. Interestingly, the result of phylogenetic analysis on mitochondrial COI and nuclear ITS1 region was, in part, inconsistent in internal branches. In this symposium, I re-analyzed more these data by phylogenetic network analysis. Based on the results, I make some inference about the process of habitat expansion of these mites.

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.

Terrestrial animals are widely considered to be well protected from damage caused by ambient UV radiation, and thus the direct effects of solar UV-B radiation on arthropods have not attracted a great deal of attention. However, if plant-dwelling arthropods have evolved behavioral adaptations to solar UV-B radiation, but not morphological or physiological adaptations, the resources available to them would be strongly limited. Tetranychus urticae and their dominant natural enemies, phytoseiid mites, usually stay on the lower leaf surfaces. Because of the accumulation of UV-B-absorbing compounds such as flavonoids in the leaves, the upper and lower leaf surfaces provide different UV environments. We tested whether UV irradiation affects survival and reproduction of T. urticae and, if so, whether staying on the lower leaf surfaces is beneficial for their performance in solar UV radiation. Consequently, we observed lethal effects of artificial UV-B irradiation and solar UV radiation on T. urticae. However, by remaining on lower leaf surfaces, the mites could avoid such deleterious effects. These suggest that staying on the lower leaf surfaces is a behavioral adaptation of T. urticae to avoiding harmful solar UV-B radiation. Lethal effects of UV-B irradiation also exerted strong deterrent effects on the hatchability of phytoseiid mites. Additionally, preliminary experiments suggested that phytoseiid mites avoided and quickly escaped from a place irradiated by solar UV. Therefore, solar UV-B radiation may strongly affect the diurnal and spatial patterns of distribution or migration of mite communities on host plant canopies.

Models are useful tools for understanding and improving biological control of arthropod pests by means of natural enemies. Thus, models can be applied to simulate various scenarios in order to identify optimal control strategies. Although simulations can never replace real experiments, they can often serve as guidelines for choosing relevant field experiments and thereby save a lot of laborious and costly field work. Whereas the processes underlying population dynamics (e.g. dispersal, functional response, mutual interference) can be studied under laboratory conditions, large-scaled experiments in the field or in greenhouses are unsuited for this purpose. Instead such experiments may provide information about the patterns (e.g. spatial distributions of prey and predators) generated by the underlying processes. A major purpose of modeling is to link the patterns to the processes that generate these patterns. Petri-dish and single plant experiments have clearly demonstrated the capacity of predacious mite Phytoseiulus persimilis to feed effectively on the two-spotted spider mite Tetranychus urticae. This quickly leads to reductions in the abundance of prey, followed by a decline in predator abundance and eventual extinction. However, when larger systems, consisting of many hundred plants, are infested with the two mite species, extinction of one or both species seems less likely at the system level, although it may still occur at the individual plant level. The qualitative difference between small and large systems with respect to persistence and extinction risks is attributed to the fact that mites move among plants, but to prove that dispersal per se plays a role for the overall dynamics is hard to demonstrate experimentally. To circumvent this problem, I developed a stochastic simulation model of a greenhouse system that explicitly incorporates within and between plant dynamics. The model is used for analyzing a series of experiments with biological control of spider mites in multi-plant systems. In these experiments, the number of plants as well as their connectivity and the numbers of introduced mites were varied in order to examine whether these factors affect e.g. the predator-prey ratio or the time to extinction of one or both species. In my presentation I will also demonstrate an interactive version of the model (called DynaMite). It allows the user to interfere in the system during a simulation so as to mimic the options a grower has in order to prevent losses and to maximize his profit. Such options include spraying with acaricides, releasing predators, and replanting in substitute of damaged plants. By choosing different control strategies, the user may gradually improve his skills according to the principle of learning by experience. The model can be freely downloaded from http://www1.bio.ku.dk/ansatte/beskrivelse/?id=43077

점박이응애, 간자와응애와 긴털이리응애에 대하여 abanectin 의 독성을 leaf disc 법으로 시험하였다. A-bamectin은 점박이응애나 간자와응애보다 긴털이리응애에 대하여 독성이 매우 낮았다. 긴털이리응애 암컷성충은 처리 농도가 증가할수록 생존율이 크게 감소하였으나, 0.38~6ppm에서 8~78%가 생존하였으며, 산란수도 농도 증가에 따라 크게 감소하였다. 모든 처리 농도에서 긴털이리응애 난의 부화나 생존 유.약충의 발육에는 영향이 없었다. 유.약충의 생존율은 농도 증가에 딸라 감소하여 0.38~3ppm에서 42~90%가 성충으로 우화하였다. 중독된 먹이를 섭식한 긴털이리응애 암컷 성충은 생존율에는 별 영향이 없었지만, 산란수와 차세대의 성비에는 상당한 영향을 받았다. 또한 긴털이리응애에 상대적으로 영향이 적어 아치사농도라할수 있는 0.38~0.75ppm에서의 abamectiondms 점박이응애나 간자와응애의 종합관리에서 긴털이리응애와 식식성응애류의 밀도비율 조절에 유요할것으로 생각된다.

The study involved determination of resistance levels of spider mites ta argano-phosphates using topical application and slide dip techniques, laboratory serening tests of alternative acaricides using an O/P resistant strain and a field trial of the screened materials. 1. Strains of Tetranychus were from Timaru(TR), Havelock Narth (HNR), Lincaln (LN). Germany (GR, GN). Comparisons of the resistant strains and normal strains at the LD50 and LC50 levels were as follows : (a) Using the topical application tochnique, with Parathian. resistant levels of the GR. TR and HNR strains of T. urticae were respeativuly, 1035. 484 and 452 times as resistant' as the LN strain. (b) Using the slide dip technique, with Phosdrin, resistant of GR, TR and HNR strains of T. urticae were 635, 274 and 266 times greater respeativuly, than the GN strain. 2. The laboratory sereaning tests were carried out far their contact plus stomach and residual effect to assess the toxicities of eleven alternative materials which would be used far control of O/P resistant strain of T. urticae. The acaricide groups represented were 3 organo-chlorines (Spidex, Kelthane and C 8514), 2 nitrophenyls (UC 19786 and Morocide), 2 cyclic carbonates(Eradex and Morestan). I carbamate (UC2004 7A), 1 mixture of carbamate and orano-chlorine and 2 other chemicals (C 8677 and M2527). From all acaricide tested. Kelthane and Morocide were the most effective, folowed by Spidex and M2527. Morestan, C8514. C8677 and RS 143 were intermediate, but Eradex, UC 19786 and UC 20046A were poor. 3, The number of sapmles required for estimation of the population in the field evaluation of acaricidal effects was one giving the highest practical precision. It was decided, after preliminary sampling trials. to use samples of 30 leaves per replicate which gave a standard error. 4. In the field trials, Morocide applied at the a. i. conc. to black currant trees gave excellent control of O/P resistant population of T. urticae for about 12 days, but Morocide 0.025 and Kel thane a. i. cone. gave efficient control for about 6 days. In other words. first applications of Kel thane ane Moroeide gave very high degrees of control of O/P resistant population of the two-spotted spider mite. However, the results indicate that secondary application would sometimes be necessary. There was no foliage damage of black Currants and strawberries by either acaricides at the concentrations used. Acknowledgment ... The authors are grateful to: Dr. R. P. pottinger, Senior Lecturer in Agricultural Zoology. Lincoln college. New Zealand. for his helpful assistance in aiding with the organization of thd field work. Department of agriculture officers for mite colonies. Mr. D. A. Slade, Technical Advisor. Fruitgrowers' Federation (now at Massey University) for his assistance and provision of mites for testing. Mr T. McRae of Timaru for permission to use his crops for field tests. The following chemical companies and I or their New Zealand agents for so readily supplying samples of acarides, Ivan Watkins-Dow Limited. Fruitgrowers Chemical Company Limited. Henry H. York & company (New Zealand). Shell Oil (New Zealand) Limited.