The American house dust mite, Dermatophagoides farinae Hughes, is the most important factor of allergic diseases, such as atopic dermatitis, rhinitis, and asthma. The protein-denaturing activity of nerolidol (1), chrysin (2), and spathulenol (3) identified in the Brazilian propolis against D. farinae was evaluated using SDS-PAGE and dot-blot immunoassay. Results were compared with those of the currently available dust mite protein-denaturing agent tannic acid. SDS-PAGE showed that application of test compounds and tannic acid (100 μg each) caused complete disappearance of D. farinae protein bands. In a dot-blot immunoassay, test compounds and tannic acid (100 μg each) strongly inhibited the IgE-binding reactivity to D. farinae protein of a highly mite-sensitive asthmatic patient. The Brazilian propolis constituents described merit further study as potential dust mite-allergen denaturants for protection from humans from various diseases caused by house dust mites.

The bulb mite (Rhizoglyphus echinopus) is damage garlic, shallot, onion in the bulbs, corms, tubers. It has recently become a serious problem because of the continuous use of acaricides resulting in resistance among bulb mite population. Thus, there is need to find alternative control measures to suppress bulb mite population. Initial screenings were performed using 352 isolates of pathogenic fungi from Korea soils. As results, 9 strains of acaropathogenic fungi were cadavers of bulb mite supporting fungal conidiation. These isolated were identified as 8 strains of Metarhizium anisopliae (4-1, 4-3-1, 4-3-2, 4-8-1, 4-4-1, 4-14-2, 4-16-1,and 4-31-2), 2 strains of Beauveria bassiana (4-4-2) by microscopic examination and genetic sequencing of the ITS region. However, ITS sequence analysis was consistent with the Metarhizium anisopliae (4-1, 4-3-1, 4-4-1, 4-31-2; a, 4-8-1, 4-14-2, 4-16-1; b, 4-3-2; c). Therefore, genetic diversity of selected in vitro isolates was characterized by Universally Primed (UP) PCR. The divided with Metarhizium anisopliae 4strain by UP-PCR. Of the 5stain isolation tested, 5stain resulted in mortality rates ≥20% within 6 days and all fungal treatment was detected mycosis. Thus these species of acaropathogenic fungi can be considered promising for biological control of bulb mite.

A mite damage was observed in spinach (Spinacia oleracea L.) under organic culture greenhouses. The mite was identified as Tyrophagus similis Volgin, 1949. It was very difficult for the farmers to diagnose the mite damage because of its tiny size about 0.5 nm in length. And the symptom was not clear at the early growth stage of the spinach because the mite mainly attack the very young leaves. In this study, we first report the spinach damages by T. similis in Korea. Informations on the mite morphology and the spinach damage symptoms are provided for the diagnosis.

This study is based on specimens which had been collected from Jeollabuk-do, Chungcheonbuk-do and Gyeonsangnam-do provinces in July 1994 through September 2009. As a result of this study, Cunaxa potchensis and C. mageei were identified and newly recorded from Korea.

Gamasid mites are top predators and occupy a central position of the soil food web in the forest ecosystem. This study investigated the soil dwelling gamasid mite community during 8-9 years after the massive mountain fire which occurred in April 2000. Total of 11 families, 44 species and 943 individuals were found. Abundance and species richness of soil gamasid mites was high in less fire-impacted sites (C2 and T3) including unburned control site (Con) than in severely impacted sites (T1 and T2). Genus Holaspina comprised 40-84% of the total abundance of gamasid mites indicating the group may play the key role in soil food web. Dominant species of gamasid mite was H. alstoni, H. communis, H. dentaus, H. ochraceus, H. trifucatus of the Genus Holaspina 5 species in all sites. Some detail biological information was pursued in this group. After 8-9 years from the massive fire, it was noted that the soil gamasid mite communities were recovered from the less severely burned sites but not from the severely burned sites.

Spider mites are one of major pests in cultivations of various ornamental plants and also important in plant quarantine service. Due to the very small body size and high similarity within the Genus the identification of species is difficult even at the microscopic observation. To identify 5 major species (Tetranychus cinnabarinus, T. urticae, T. phaselus, T. kanzawai and T. truncatus) in the Genus Tetranychus at the molecular level, we designed 4 species-specific primer sets using nucleotide sequences of the internal transcribed spacer (ITS2) region in the nuclear ribosomal repeat unit. At the PCR diagnosis of extracted genomic DNAs of 5 species using each primer set, specific primers of both T. phaselus and T. truncates were species-specific to their own species samples. However, specific primer set of T. urticae detected T. cinnabarinus as well as T. urticae. Specific primer set of T. kanzawai detected T. truncates as well as T. kanzawai, even though detection intensities were lower in non-target species.

2009년 4월부터 8월까지 쭈쭈가무시병의 다발생지역으로 알려진 중부지방의 충남 아산시, 경기 평택시와 화성군 3개 지역에서 털진드기의 개체군 밀도를 조사하였다. 채집된 들쥐는 총 48마리였는데 이 중 등줄쥐(A. agrararius)가 45마리로 93.8%를 차지하여 절대 우점종이었고, 갈밭쥐(Microtis fortis)가 1마리(2.0%)였으며, 땃쥐(Crocidura laisura)가 2마리(4.2%)였다. 조사 기간 중 전 지역에서 채집한 털진드기는 총 290개체였다. 채집된 털진드기는 1속 4종이었는데 이중 대잎털진드기(Leptotrombidum pallidum)가 234개체로 80.7%를 차지하여 우점종이었고, 동양털진드기(L. oriental)가 30개체(10.3%), 수염털진드기(L. palpale)가 10개체(3.4%), 반도털진드기(L. zetum)가 16개체(5.5%)였다. 대잎털진드기는 3개 지역(충남, 평택, 화성)에서 절대 우점종으로 나타났다. 충남 아산지역에서는 대잎털진드기, 수염털진드기, 동양털진드기, 반도털진드기 4종이 서식하는 것으로 나타났으며, 경기 평택지역에서는 대잎털진드기, 동양털진드기, 반도털진드기 3종이 서식하며, 경기 화성지역은 대잎털진드기, 수염털진드기 2종만이 서식하는 것으로 나타났다.

The toxicity of 10 plant essential oils to adults of acaricide-susceptible, chlorfenapyr-resistant (CRT-53), fenpropathrin-resistant (FRT-53), pyridaben-resistant (PRT-53), and abamectin-resistant (ART-53) strains of Tetranychus urticae Koch and to female Neoseiulus californicus McGregor was examined using spray or vapor-phase mortality bioassays. In bioassay with the susceptible adults, strong toxicity was produced by lemon eucalyptus, peppermint, citronella Java, thyme red, caraway seed, pennyroyal, and clove leaf essential oils (LC50, 0.0193-0.0327 mg/cm3). The toxicity of these essential oils was almost identical against adults from either of the susceptible and resistant strains, even though CRT-53, FRT-53, PRT-53, and ART-53 adults exhibited high levels of resistance to chlorfenapyr [resistanc ratio (RR), >9140], fenpropathrin (RR, 94), pyridaben (RR, >390), and abamectin (RR,85), respectively. Against female N. californicus was 1.0 to 1.9 times more tolerant than T. urticae to the test essential oils. Thus, these essential oils merit further study as potential acaricides for the control of acaricide-resistant T. urticae populations as fumigants because of their lower toxicity to N. californicus.

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.

By releasing predatory mite, Amblyseius swirskii Athias-Henriot, with 25 individuals per cucumber plant in a commercial greenhouse (1,600 ㎡), the population of western flower thrips, Frankliniella occidentalis (Pergande), was kept under the economic threshold level. The initial thrips population of 18.3 individuals per leaf decreased to 2.1 individuals per leaf after four weeks, while the number of A. swirskii reached to 16.6 individuals per leaf. It was also observed that at a point where the thrips occurred in high density of about 34.3 individuals per leaf, A. swirskii population built up on the lower part of cucumber plant first, but as time passed the predatory mites moved upward to the top of the plant and aggregated.

This study was conducted on the biological control effects of the natural enemy, Amblyseius cucumeris , against Polyphagotarsonemus latus. The broad mite moved to a new habitat after the carrying capacity of the preferred habitat on the upper leaf has been reached. Population dynamics between predator, Amblyseius cucumeris, and prey, P. latus, were quite well synchronized since the predator followed the movement of the prey. In predation test by Amblyseius cucumeris on P. latus, A. cucumeris fed on 8.8, 15.2, 27.0 and 30.3 individuals/day under the temperatures of 15, 20, 25, and 30℃, respectively. The A. cucumeris larva, protonymph, deutonymph, adult male, and adult female fed on 0.5, 1.6, 5.2, 3.8, and 27 individuals of adult P. latus per day, respectively, under 25℃ condition. The functional response curve of adult P. latus to the densities of A. cucumeris showed Holling’s Type Ⅱ curve. The consumption of prey by A. cucumeris increased with the prey density increase, but the consumption rate decreased. The critical ratio of predator vs. prey effectively to suppress (98% over) the population of P. latus by releasing A. cucumeris was 1:40 on red pepper.

This study was conducted to determine whether trichome density affects the oviposition behavior of adult female Tetranychus urticae Koch on host plant leaves. Experiments were conducted with twenty replications on the leaf discs of each plant (Pear, 'Niitaka'; Apple, 'Fuji'; Strawberry, 'Meahyang'; 3cm diameter) at 25℃, 60-70% RH and a photoperiod of 16:8 (L:D) h. One female T. urticae was placed on each disc. The number and locations of laid eggs were recorded at 24 h intervals until T. urticae died. The trichomes were distributed along the midrib of abaxial surface of pear leaves but were evenly distributed on that of apple and strawberry leaves. Eggs were mostly laid along the midrib of pear leaf disc, but eggs were laid not only along the midrib but also randomly over the leaf disc of apple and strawberry. Therefore, it appeared that T. urticae preferred to lay eggs on the specific location where trichomes were densely distributed. Further study is needed to quantify how different distribution patterns of T. urticae eggs on different plant leaves affect the efficacy of predatory mites to control T. urticae.

Predation, development, and ovipostion experiments were conducted to evaluate Amblyseius swirskii (Athias-Henriot) (Acari: Phytoseiidae) as a potential biological control agent for tomato russet mite, Aculops lycopersici (Massee) (Acari: Eriophyidae) which is a periodic pest of greenhouse tomatoes. Results show that A. swirskii attacked all developmental stages of A. lycopersici, and had a type II functional response on the prey densities given. The predation rates of A. swirskii on A. lycopersici in the presense of alternative food sources such as pollen, thrips first instar, or whitefly eggs were recorded as 74%, 56%, and 76%, respectively of the predation rate on A. lycopersici alone. Amblyseius swirskii successfully completed their life-cycle on either A. lycopersici or cattail pollen. At 25oC, 70% RH, development time of female A. swirskii fed on A. lycopersici or on cattail pollen took 5.0 and 6.2 days, respectively. For the first 10 days after moulting to the adult stage, A. swirskii fed on A. lycopersici had higher daily oviposition rate (2.0 eggs per day) than on pollen (1.5 eggs per day). From this laboratory study, it can be concluded that A. swirskii has promising traits as a predator against A. lycopersici and that their populations can be stably maintained using alternative food such as cattail pollen. We suggest that the effectiveness of A. swirskii against A. lycopersici under field conditions deserves to be investigated.

The objective of this study was to evaluate the effective inoculation position of Neoseiulus californicus for control of Tetranychus urticae on apple branch. This study was conducted under green house conditions. N. californicus was inoculated at different position (Top, Middle and Bottom) of apple branch with a 20:1 ratio (T. urticae:N. californicus). Overall, N. californicus significantly reduced T. urticae numbers in the treatment branches than in the control branch. At 10th day, the T. urticae population was most significantly reduced in the treatment ‘Top’ in which N. californicus were inoculated on the leaf positioned in the top of a branch than in other treatments. At 20th day, most of T. urticae were exterminated in all treatment branches. The daily movement of N. californicus and T. urticae,and their coexistence on apple branch was monitored. Adult N. californicus disappeared from the branch as soon as T. urticae were exterminated in the treatment branches. The result indicates that N. californicus disperse downwards more than upwards in the tree, and the most effective inoculation position for N. californicus for control of T. urticae is the leaves positioned in the top of a branch.

The study was conducted to explore whether environmental differences, in this case the physical characteristics of abaxial leaf surfaces of strawberry cultivars ('Maehyang' and 'Sulhyang' cultivars), affect the functional response of adult female N. californicus preying on immature stages (egg, larva and nymph) of T. urticae. We also evaluated the functional response of N. californicus to eggs of T. urticae at different temperatures (15, 20, 25, 30 and 35℃). We conducted a logistic regression of the proportion of prey consumed as a function of initial prey density to identify functional response types, and used nonlinear squares regression and the random predator equation to estimate attack rates and handling times. The functional response of adult female N. californicus to T. urticae was not influenced by non-glandular trichomes and epicuticular waxes on the abaxial leaf but was affected by temperature. Overall, the functional response of adult female N. californicus exhibited a type 2 functional response to T.urticae. The handling time of N. californicus was highest (1.9970) against T. urticae nymphs. The attack rate did not change much at 15-30℃, but the handling time decreased linearly with increasing temperature. At 35℃, the attack rate was highest (0.1876) and the handling time was lowest (0.9296). The results of this study may be used to evaluate the potential of N. californicus to suppress T. urticae and to estimate parameters for relevant prey-predator models.

Economic injury levels (EILs) and economic threshold (ET) were estimated for the two spider mite, Tetranychus urticae Koch (Acari, Tetranychidae) on greenhouse eggplants. T. urticae density increased until the mid-July and thereafter decreased in all plots where initial density of the mite were different each 0, 2, 5, 10 and 20 adults per plant was innoculated on June 7. Growth variables of were not different among experimental plots but fruit weights were lower in plots with higher initial mite density than in plots with lower initial mite density. Total number of fruits and the number of marketable fruits decreased in plots with higher initial mite density. The rates of yield loss increased with increasing initial mite density, resulting in 0, 3.9, 11.3, 14.5, 22.8% reduction in each of the above plots, respectively. The relationship between initial T. urticae densities and yield losses was well described by a linear regression, Y = 1.085X + 2.474, R² = 0.9659. Based on the relationship, the number of adults per plant which can cause 5% loss of yield was estimated to be approximately 1.8.

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.

Effects of starving treatment on the gravid females of N. californicus were investigated at 20°C and 85% RH. When the females were reared without prey and water just after they laid the first egg under the abundant prey condition, they laid 1.8 eggs and survived for 4.3 d. In order to investigate the process of oogenesis in the body of the starved females, females just after laying the first egg were reared for 0, 12, 24, 36, 48, 72, and 96 hr without prey and water, and were then prepared for internal observation. In the body of females of 0hrstarvation, an egg with eggshell and two oocytes were observed in the ventral and dorsal regions, respectively. Larger oocyte had 2 roundish nuclei and abundant yolk granules, and was enveloped with vitelline membrane. These 2 nuclei were not fused but were just conjugated. Smaller oocyte had a nucleus, but did not form yolk granules and vitelline membrane. Females of 12hrstarvation had an egg in the ventral region and an oocyte in the dorsal region of the body. Females of 24hr-starvation maintained an oocyte in the dorsal region of the body, but did not have an egg in the ventral region. The oocyte was filled with abundant yolk granules, and held 2 irregular-shaped nuclei. Females starved more than 36hr also maintained only an oocyte in the dorsal region of the body. Only an irregular-shaped nucleus was observed in the oocyte. These micrographs suggested that (1) gravid females maintained an oocyte in the dorsal region after laying 2 eggs during starving treatment, (2) the oocyte was not absorbed during starvation, (3) the oocyte advanced vitellogenesis and the fusion of 2 nuclei, and (4) the oocyte was not enveloped with eggshell and did not start embryogenesis. It is also assumed that the sperm penetrated into the oocyte without yolk granules, although the penetration was not observed in this study.

Temperature is an important inorganic factor which affects on every aspect in life of phytoseiid mites in general including N. californicus in this study. Cumulative and short-term effects of temperature through different life stages (immature, mating and oviposition periods) on mating duration and total fecundity of N. californicus were investigated at temperatures of 18, 25, 30 and 350C with a photoperiod of 16L:8D. Throughout experiments, females mated once and egg production was observed until they stop oviposition.

The European red mite (ERM), Panonychus ulmi, and the two-spotted spider mite (TSSM), Tetranychus uritcae, are serious mite pests in pome fruit orchards worldwide. Abundance and species composition of spider mites in orchard ecosystem have been changed historically in many countries. To illustrate the cause for the historical changes in species composition between ERM and TSSM is an interesting topic. The abundances of the two mite populations have been largely changed in Korean apple orchards: ERM was dominant until 1970s, TSSM has been dominant from 1980s, and then ERM has increased abundantly in some orchards in recent years (Lee, 1990; Kim and Lee, 2005). In apple orchards in Japan, Amphitetranychus viennensis outbreaks occurred immediately after the use of organophosphates in the early 1950, and then, ERM became dominant species on apple until the 1960s followed by TSSM abundance from the late 1970s to the early 1980; Recently, ERM again increasing in IPMadopted apple orchards (Reviewed in Morimoto et al., 2006). Kishimoto (2002) showed changes in the species composition of spider mites caused by different pesticide spray programs in Japanese pear orchards. Pesticides can become an important factor that affects mite species composition of mites through the process of resistance development and the removal of natural enemies. Pesticide resistance and the removal of natural enemies can explain the outbreak of spider mites in orchards, but do not fully explain the changes in species composition of mites. Morimoto et al. (2006) reported a possible exclusion of ERM by TSSM through interspecific interaction via their web: the complicated web created by TSSM increases the mortality of little webspinning species such as ERM. Morimoto et al. (2006) stated that the change in mite species composition can occur as a result of interspecific association between spider mites via their webs, without pesticide applications or the presence of natural enemies. However, their hypothesis does not explain the dominance of ERM in orchards under lower pesticide pressure. Also, Belczewski and Harmsen (1997) concluded that the application of additional or supplemental amounts of a Phylloplane fungus (Alternaria alternata) to apple leaves enhanced the population growth of TSSM compared to that of ERM. However, this does not explain the dominance of TSSM in orchards under heavy pesticide pressure where Phylloplane fungal population would be lowered by fungicides, and the dominance of ERM in unsprayed orchards where Phylloplane fungal population would be abundant because of no fungicide application. The change in species composition among spider mites can not be projected with any single factor. It is required to examine all possible combinations of factors involving. Until now the change in abundance between ERM and TSSM has not been examined comprehensively. Therefore, we examine possible changes in population abundance between REM and TSSM with some assumptions. Also, case studies that deal with long-term and short-term changes between the two mites are presented.