The Kanzawa spider mite, Tetranychus kanzawai (Acari: Tetranychidae) constructs webs over leaf surfaces and usually lives under the webs. T. kanzawai produces two types of excreta, black and yellow pellets, and uses its webs as a place for excretion. T. kanzawai also uses its webs as a refuge when the predatory mite, Neoseiulus womersleyi (Acari: Phytoseiidae) is present. To clarify what factors deter N. womersleyi from foraging on T. kanzawai webs, I experimentally examined the effects of T. kanzawai excreta on its own fitness (fecundity) and the foraging behaviour of N. womersleyi. When the excreta of T. kanzawai was put on leaf surfaces, the fecundity of T. kanzawai adult females was reduced by the black but not the yellow faecal pellets. On the other hand, predation by N. womersleyi was reduced by the yellow but not the black pellets. Although this effect of the yellow pellets on N. womersleyi did not last on leaf surfaces, it deterred N. womersleyi from staying on the webs regardless of its freshness. These results suggest that T. kanzawai deposits black pellets on webs to avoid its negative effect on their own fitness, and yellow pellets are deposited on webs to reduce the risk of predation.

Nicrophorus concolor Kraatz is a large burying beetle widely distributed in East Asia including Japan, and well known for the habit of burying dead small vertebrates to feed their offspring. Taxonomic research on hististomatid deutonymphs phoretic on this beetle has revealed that they are classified into seven distinct species all new to science, one of which was already described by us under the name Pelzneria uncinata. Now, we give an account of another new species of Pelzneria phoretic on N. concolor in Japan, mainland China and Taiwan. The deutonymphs of the new species are found frequently together with P. uncinata, but, unlike this species, in various, more or less cryptic places on the body surface of the beetle, which indicates that the new species does not show distinct preference of location on the host beetle. The present new species is easily distinguished from the known congeners by hysterosomal dorsum with anterior margin widely and arcuately protruded medially and crenate laterally, unusual forward displacement of dorsal hysterosomal setae d1, notably stout setae f, p and r on tarsus III, extremely long terminal seta e on tarsus IV, and so forth. The feeding stages of this mite are considered to feed on the carcasses of small vertebrates buried by adult N. concolor.

Community analysis of oribatid mites was conducted in unburned and burned area of Samcheok-si, Gangwon province with differential burn severity that occurred in April 2000. Except control site, four sites (T1, T2, T3 and C2) were selected according to burn severity and subsequent recovery following a year after fire form T1 (heavily burned) to Control (unburned). This study analyzes the abundance, species richness, diversity and evenness, similarity, dominant species, and MGP types of oribatid mites. Oribatid mites were sampled 8times from each site from 2005 to 2007. Total of 40 families, 58 genus, 123 species and 4,638 individuals were founded. Species richness and abundance of oribatid mites decreased as burn severity increased. Diversity index of control site was higher than all other sites and decreased as the burn severity increased. Similarity between control and C2 sites was highest among the sites and cluster analysis showed control and C2 as closely related followed by T3, T2 and T1 respectively. MGP-I analysis revealed oribatid mites of all sites as GP type. MGP-II analysis showed control as G type and all other sites as GP type.

A phytoseiid mite, Neoseiulus californicus was newly found from Jeju citrus orchards in Korea and it is a polyphagous predator of mite and small insect pests as well as plant pollens. Recently in Korean apple orchards, Tetranychus urticae and Panonychus ulmi are imposing similar pest pressure. Even with ample information of this predator interacting with T. urticae, little is known on the interaction with P. ulmi. We investigated temperature effects on life history parameters of N. californicus when feeding on P. ulmi as prey in the laboratory condition to check the possibility to use this predatory mite in apple mite biological control. So, the development, survivorship and life-table parameters of the predator were studied by given mixed stages of P. ulmi as prey under the range of temperatures (15-34°C), RH 75±10%, and photoperiod 16L:8D to determine the effects of temperature. Temperature had a significant effect on mean development time from hatching to adult emergence and other life-history parameters. The results specified that the developmental time is decreased with increasing temperature between 15 and 30oC. Female development times were shorter at 25, 30 and 34°C (3.83±0.07, 3.37±0.24 and 3.53±0.11d, respectively) and were longest at 15°C (15.61±0.22d). Male developmental times were shorter than females ones at each temperature. The highest adult female life span (70.42±3.06d) and oviposition period (35.83±1.43d) observed at 15oC whereas the shortest at 34oC (13.06±1.03 and 7.3±0.94d, respectively). At 25oC, females laid maximum number of eggs (63.94±2) while minimum (16.59±0.98) was at 34oC. In sex ratio, utmost number of females (0.77±0.01) was counted at 25oC and lowest (0.67±0.01) at 34oC. Survivorship during immature development varied from 78.78 to 93.75% with the lowest value recorded at 20 and 34oC. From life table analysis, the shortest generation time (T=10.7d) resulted at 34oC. The highest net reproductive rate (R0=44.31; expected progeny per female) was found at 25oC. The intrinsic rate of natural increase (rm=0.29) and the finite rate of increase (λ=1.33) per day was estimated highest at 30oC. From this study, we found that N. californicus could successfully develop and oviposit vital eggs. Based on these results, we cautiously expect that N. californicus could be used as a biocontrol agent of spider mites in apple orchards when P. ulmi or T. urticae occurs singly or mutually.

Neoseiulus californicus (McGregor) is a potential biological control agent of spider mites in orchards. The field occurrence of this species was first reported from citrus orchards in Jeju Island and recently this mite started to be sold as a commercial product in Korea. However, the natural occurrence of N. californicus in the Korean mainland is unclear or quite limited. At this time, it is not certain whether N. californicus can overwinter in the Korean mainland or not. This mite is presently planning to be used as a biological control agent against spider mites in apple orchards of the Korean mainland. The main objective of this study was to investigate natural overwintering sites of N. californicus and possible factor increasing winter survival of this species, to develop effective method for collecting overwintering population of N. californicus. For the first objective, we conducted field survey in two citrus orchards of Jeju in early and late February 2008. Samples were collected from various possible overwintering sites: citrus trees, ground covers and windbreaks. Total 259 phytoseiid mites were collected, 94% of the mites were identified as N. californicus and 98% of them were adult females. Most of N. californicus were collected from ground covers, specially the weed species which had rosette leaves: Youngia japonica (L.) DC. and Erigeron spp. This result seemed to suggest that N. californicus try to hide beneath weed leaves near ground surface during winter to get successful survival. Thus, the second experiments were conducted in Andong from December 2007 to early March 2008. N. californicus conditioned in a greenhouse with natural day length was individually put in a small tube, and the tubes were kept under different ground surface conditions: bare, fallen leaves and urethane foam. When water had been added in the tube, the mites on bare ground had died after one month, while 70% of the mites of the other cover treatments were surviving. In these cover treatments, 7-10% of the mites had survived until two months, and eventually all died within three months. This result showed that hiding under cover structure near ground surface may be effective to increase winter survival of N. californicus. Therefore, collecting weeds which have rosette leaves may be an effective method to estimate of the overwintering possibility of N. californicus in the Korean mainland.

In Jeju cirtrus orchards, Panonychus citri, citrus red mite is the most important pest requiring 3 times acaricide sprays. In open field conventional orchards, P. citri usually shows three population peaks; from end of Jun to July, from end of Aug. to Sep., from end of Oct. to Nov. However, natural enemy complex and its function regulating P.citri are poorly understood. From the survey of P.citri natural enemy in citrus orchard in Jeju from 2004 to 2006, predatory beetle, Oligota spp. was most abundant. Three predatory mite, N. californicus, Amblyseius eharai, and N. barkeri, were identified. Among them, the predatory mite, Neoseiulus californicus (McGregor) (Acari: Phytoseiidae), was first found in Korea. Even though it was first found, N. californicus was the dominant species occupying 84% of phytoseiid mites. These predatory mites mostly occurred in Jun and peaked at July, which was accorded with the high humidity season of the year. From the survey, the density relationship with P. citri was unclear. From the study conducted in 2005-2007, N. californicus was more abundant in greenhouse citrus (var. Shirahuhi) than in open field orchards; conventional or organic mandarine citrus. In greenhouse citrus, phytoseiid mites showed suppressing P. citri population. As a next step, the inundative biological control study was conducted using commercial strain of N. californicus, which was originated from Jeju, 2005, in greenhouse citrus. One thousand N. californicus per 1a were released 2 times at 10 day interval on citrus leaves when the initial density of P. citri was about 0.2 per leaf. The release effects were variable depending on the field condition. However, N. californicus did successfully reduce P. citri in greenhouse citrus orchards.

Population density of the citrus red mite, Panonychus citri (McGregor), in Japanese pear orchards remained low until mid-August, even after inoculation of pear leaves with a considerable number of adult female P. citri from May onwards. This raised the possibility that pear leaves contain a natural compound that suppresses an increase of P. citri populations. The rate of development from larva to adult was significantly lower on leaves collected in July than on leaves collected earlier or later, in several years. The population suppression was caused by molting inhibition and ovicidal activity, according to our close observation in the laboratory [Gotoh and Kubota (1997) Exp. Appl. Acarol. 21: 343-356]. To clarify whether a natural pear compound caused this molting inhibition, a methanol crude extract of pear leaves was isolated and added to a newly developed artificial diet, consisting of sodium caseinate, sucrose, levulose, glucose and inositol. The compound extracted from pear leaves resulted in the molting inhibition as observed on pear leaves. Based on infrared and NMR spectral analysis, the compound extracted from pear leaves closely resembled the synthetic acaricide hexythiazox. Furthermore, the LC50-values of the compound extracted from pear leaves for ovicidal activity of P. citri eggs and for inhibition of molting to protonymphs were similar to those of hexythiazox. These results strongly suggest that the molting deterrent extracted from pear leaves was in fact hexythiazox, an acaricide in use on pear trees, rather than a natural product. This suggestion becomes even stronger, considering that the molting inhibition was observed in a hexythiazox-spray year, but not in a non-spray year.

Temperature dependent development of Tetranychus. urticae Koch was studied on the leaf of eggplant at 17, 22, 27, 32 and 37℃, T. urticae showed a minimum mortality at 27℃ and it increased at higher or lower temperatures than 27℃. The hatchability was low at 17 and 37℃. The duration of development decreased with increasing temperatures i.e., 5.3d at 37℃ and 25.8d at 17℃. Linear regression analysis of temperature vs. rate of development yielded the higher r² ≥ 0.88 resulting in a good fit of the estimated line in the range of 17~37℃. Developmental zero temperature was 12.5℃ for the entire immature stage of female and 12.8℃ for that of male. Thermal constants were 80.5 and 74.7 degree days for those of female and male, respectively. Adult life span and oviposition period decreased with increasing temperatures. The number of eggs laid per female peaked at 141.0 eggs at 27℃, while that was a minimum 78.0 eggs at 37℃. Rate of hatchability, ratio of female, and R₀ were increased up to 27℃, and than declined thereafter. Intrinsic rate of natural increase (Rm) increased with rising temperatures and showed a maximum 0.5652 at 37℃. Also, λ increased with increasing temperature. Doubling time (Dt) and generation time (T) decreased with increasing temperature.

The developmental time and survival of immature stages of N. californicus were studied under laboratory conditions at nine constant temperatures (12, 16, 20, 24, 28, 32, 36, 38, 40℃), 60-70% RH, and a photoperiod of 16:8 (L:D) h. The total developmental period decreased with increasing temperature between 12 and 32℃, and increased beyond 32℃. Total developmental period of immature stages was longest at 12℃ (18.38 days) and shortest at 32℃ (2.98 days). The cumulative mortality of N. californicus was lowest at 24℃ (4.5%) and highest at 38℃ (15.2%). The normalized cumulative frequency distribution of developmental times for each life stage was fitted to the three-parameter Weibull function (r2=0.91~0.93). The relationship between temperature and developmental rate was fitted by five nonlinear development rate models (Logan 6, Lactin 1, 2, and Briere 1,2). The nonlinear shape of temperature development was best described by the Lactin 1 model (r2=0.98). The determined lower developmental temperature thresholds could be used to predict the occurrence, number of generation and population dynamics of N.californicus on fruit orchards and greenhouse

지중해이리응애(Amblyseius swirskii Athias-Henriot)는 담배가루이와 총채벌레의 밀도를 동시에 억제할 수 있는 생물적 방제원으로서, 그 활용가치가 증가하고 있는 천적이다. 2007년 국내 도입된 후 산업화가 이루어지고 있으나, 이에 대한 생물적 특성은 명확히 구명되지 않고 있다. 본 연구는 온도별 발육 특성 연구를 통하여 대량생산 및 생물적 방제의 기초 자료 제공을 목적으로 하였다. 지중해이리응애는 (주)나비스에서 분양받아, 설탕응애를 먹이로 하여 실내 사육 후 항온조건(15, 20, 25, 30, 35℃)에서 발육단계별 발육기간, 성비, 성충의 일평균산란수를 조사하고, 이 자료를 바탕으로 발육영점온도와 유효적산온도를 추정하였다. 상대습도는 75% 내외, 광주기는 16L:8D로 고정하고, 조사는 12시간 간격으로 실시하였다. 온도가 증가함에 따라 발육기간이 짧아지다가 35℃에서는 다시 증가하는 비선형 패턴을 보였다. 15℃에서 15.9±1.01일로 가장 길었고, 30℃에서 4.7±0.25일로 가장 짧았다. 15℃에서 30℃ 사이의 발육속도는 선형모델에 적합하였고(각각 r2>0.95), 발육영점온도는 유충이 8.6℃로 가장 낮고, 알이 12.8℃로 가장 높게 추정되었다. 성충까지의 유효적산온도는 7.7℃를 기준으로 123.9DD로 추정되었다. 성충의 성비는 암컷 비율이 0.65 (n=66)으로 나타나, 통상적인 포식성이리응애류의 암컷 비율과 비슷하였다. 조사한 일일 평균 산란수는 20℃에서 1.35±0.18, 25℃에서 1.64±0.99, 그리고 30℃에서 4.08±1.75, 35℃에서 0.70±0.47로 30℃에서 일일 산란수가 가장 많은 것으로 나타났다.

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.

본 연구는 훼손되지 않은 천연보호림인 점봉산의 고도 1,000미터 지점의 이웃한 남북사면의 서식처 환경차이에 따른 날개응애의 군집구조를 분석을 통한 생태계 구조를 이해함을 목적으로 1994년 5월부터 1996년 8월까지 매월 조사를 수행하였다. 두 조사지에서 채집, 동정한 날개응애의 종수및 개체수 비교에서는 유의성 있는 차이를 보였는데(t-test, p〈0.05), 북사면의 평균 밀도와 종수는 99.2±17.6, 24.7±3.0이고 남사면에서는 234.2±62.6, 40.8±5.8였다. 종다양도는 남사면이 3.09±0.11로 북사면 2.71±0.13보다 높게 나타났다. 날개응애의 개체군 크기를 전체 밀도에 대한각종의 밀도 백분율로 구하여 우점종, 중세종 그리고 약세종으로 나누어 나타내었고, O. nova와 Suctobelbella naginata가 조사지 모두에서 우점종으로 나타났고, Trichogalumna nipponica는 남사면에서는 우점종이었으나, 북사면에서는 채집이 되지 않는 종이다. 두 조사지의 우점종의 먹이 습성은 토양미생물을 섭식하는 식균성(microphytophagous) 이었다. 고도 1,000미터 지점으로 서로 이웃한 남/북사면 조사지에서 종수 및 개체수, 우점종 구성이 뚜렷한 차이를 보였고, 조사지별 유사도가 낮게 나타나 미소환경의 이질성이 날개응애 군집의 특성에 큰 영향을 미침을 알 수 있었다

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.

The toxicities of 37 commercial pesticides for citrus pests were evaluated to N. fallacis. Eight fungicides (difenoconazole, imibenconazole, azoxystrobin, dithianon, fluazinam, procymidon, strep-tomycin, tribasic copper sulfate), three insecticides (dichlovos, imidacloprid, thiamethoxam) and four acaricides (milbemectin, tetradifon, dicofol, spirodiclofen) had lower effect to the hatchability of eggs N. fallacis. Six fungicides (propineb, difenoconazole, imibenconazole, azoxystrobin, dithianon, procymidon) and three acaricides (bifenazate, tetradifon, spirodiclofen) showed lower contact toxicity to adult N. fallacis. The secondary toxicity of 26 pesticides to N. fallacis adult were evaluated. Two fungicides (fluazinam, streptomycin) and 3 acaricides (machine oil, cyhexatin, halfenprox) showed low toxicity when the prey (eggs of spider mite) was treated with pesticides.

Predation of Neoseiulus fallacis was observed for biological control of Panonychus citri that is one of the major insect pests on citrus. The daily predation of development stages of P. citri by an adult female of N. fallacis were 20.1 eggs, 26.1 larvae, 18.2 protonymphs, and 7.4 deutonymphs at 25℃. The daily predation of P. citri eggs by N. fallacis was observed under different temperatures. The predation was increased as the temperature rise. At this time, ratio of eggs production of N fallacis after predation of P. citri eggs (number of eggs N. fallacis/number of eggs P. citri consumed by N. fallacis) was 0.09. The daily predation of P. citri eggs by N. fallacis was 21.1, 17.3, and 16.7 on the different arenas (diameter: 20, 40, and 60 ㎜), respectively. The predation was decreased as the arena of the leaf increase. The functional response of N. fallacis to P. citri showed Holling"s Type Ⅱ response: the consumption of prey by N. fallacis increased as the density of prey increase but increasing rate was gradually reduced. As the result, it seemed that N. fallacis can be use for biological control of P. citri.

Effectiveness of Orius strigicollis (Poppius) and Amblyseius cucumeris (Oudemans) as natural enemies against thrips were evaluated on greenhouse green pepper, sweet pepper and cucumber respectively. Control efficacy was calculated by the formula, (D<SUB>control</SUB> - D<SUB>treatment</SUB>)/D<SUB>control</SUB> × 100, where D<SUB>control</SUB> is the average density of thrips on the plots in which any natural enemy was not released and D<SUB>treatment</SUB> is the average density of thrips on the plots in which natural enemies were released respectively. As a result, control efficacies of O. strigicollis against Frankliniella occidentalis (Pergande) on green pepper and sweet pepper were 14.3~99.5% and 21.6~98.3%, respectively. In addition, control efficacy of it against Thrips palmi Kany on cucumber was 61.2-74.4%. Control efficacies of A. cucumeris against F. occidentalis on green pepper and sweet pepper were 12.9~38.3% and 17.1~87.0%, respectively. Control efficacy of it against T. palmi on cucumber was 90.4~97.4%. Field evaluation showed that the prompt applications of natural enemies were effective to reduce the density of thrips. In detail, to control F. occidentalis effectively on green pepper and sweet pepper in spring season, five to six individuals of O. strigicollis per crops should be released three to six times continuously. To control T. palmi effectively on cucumber in autumn, more than 100 individuals of A. cucumeris per crop should be released four times repeatedly.

수원시 이목동에 있는 원예연구소의 사과원에서 조사한 1958년부터 1998년까지 자료를 바탕으로 사과응애와 점박이응애의 역사적 발생변동 과정을 추적하였다. 1970년까지는 사과응애가 우점하였고 1980년 이후에는 점박이응애로 우점종이 바뀌었으며, 그 변화는 1970년 중반을 전후로 나타났다. 이러한 변화를 설명하기 위하여 3가지 가정, 즉 첫째, 두 종의 경쟁에서 점박이응애가 승리한다. 둘째, 과원의 초생은 점박이응애의 수상이동 여부를 결정하는 중요한 요소이다, 즉 초생이 파괴되었을 때 점박이응애의 수상이동이 촉진된다. 셋째, 과원생태계가 교란되지 않을 때 응애류는 천적에 의하여 개체군 밀도가 조절된다 하에 약제살포(고독성 비선택적 약제 처리 및 선택적 저독성 약제처리)와 초생관리(초생재배 및 청경재배=제초제 살포)에 따른 두 종의 장기적 상호작용 결과를 추정하였다. 고독성 농약/초생재배 시스템에서는 점박이응애의 수상이동이 제한되어 사과응애는 경쟁을 피할 수 있고, 또한 천적상이 파괴되기 때문에 전 생육기간 동안 사과응애가 우점한다. 고독성 농약/청경재배 시스템에서는 계절초기부터 점박이응애가 수상으로 이동하여 사과응애를 경쟁적으로 배제시킴으로써 점박이응애가 우점한다. 저독성 농약/초생재배 시스템에서는 점박이응애의 수상이동이 제한되어 사과응애가 우점하지만 천적의 작용으로 높은 밀도를 형성하지 못한다. 저독성 농약/청경재배 시스템에서는 점박이응애가 수상으로 이동하여 사과응애와 경쟁하지만 천적의 작용으로 밀도가 낮아져서 경쟁압력이 낮아지므로 생육후기 사과응애의 발생이 가능하다. 따라서 계절초기 사과응애, 계절후기 점박이응애가 우점하는 형태로 공존할 수 있다. 본 자료에서 제시한 점박이응애 우점화 현상은 부분적으로 고독성 농약/청경재배 시스템 상태에서 두 종의 장기적 상호작용의 결과로 설명될 수 있었다. CAD를 이용하여 살펴보고자 한 것이다. 연구방법으로는 가장 일반적인 실로 묶기, 전통적인 손바느질 느낌이 나는 시침질, 현대적 느낌이 강한 깡통에 의한 묶기와 기하학적 효과가 나는 접기 등의 홀치기염색 기법으로 수작업 한 다음 CAD를 이용하였다 연구의 결과는 다음과 같다. 첫째, 홀치기염색기법에 의해 제작된 패턴을 모티브로 하여 수작업에서 얻지 못하는 다색사용가능성이 주�