It is widely believed that diversity of soil animals are poorer in the tropical zone than in the temperate zone. Is this right? Then, I compared Asian oribatid faunae of the following localities: a tropical lowland rain forest in Pasoh Forest Reserve (Peninsular Malaysia), a subtropical forest in Yunnan Province (China), warm temperate forest in Chiba, a cool temperate forest in Sapporo (Japan), and in a taiga in arctic zone in Siberia (Russia). Samplings in a primary forest and in a 40-year secondary forest, which were 2 ha each and adjacent to each other, showed about 100 oribatid species there. Total species number was estimated at 135 to 150 with Jackknife method. This shows that the species diversity of oribatids are rich in tropics as compared with that in the temperate Japan. Oribatid species richness was even lower in Siberia (Yakutsk) than in Japan. These indicate that oribatid diversity in tropics is higher than in other areas of higher latitudes. Analyses based on Motomura's geometric series rule showed that the inclination became steeper with latitude, also suggesting that a high species diversity in the tropics. Although the number of families did not change greatly with latitude, a DCA analysis showed that composition of families was related with latitude. It was shown that a low latitude area has many winged oribatid mites, such as Haplozetidae, Protoribatidae, and Galumnidae, with many primitive groups in a high latitude area, such as Brachychthoniidae and Hypochthoniidae.

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.

The mites of the superfamily Eriophyoidea are of worldwide distribution, and invariably associated with plants. They are extremely small in size with average 200 ㎛ of adult body length ranging from 80 to 500 ㎛, and thus often invisible to the naked eyes without noticeable deformation and/or injury on the host plants. Their general appearance is rather worm-like, with an elongated and transversely annulated opisthosoma, and with only 2 pairs of legs having a empodial featherclaw instead of paired true claws. The extremely small size and secret habits of eriophyoid mites cause them to be ignored or overlooked, and make them little understood and appreciated, although they are obligatory plant feeding mites being distributed in most botanical biosphere of the world. Nevertheless, some species are of considerable economic significance as the tomato russet mite (Aculops lycopersici), Citrus rust mite (Aculops pelekassi), pear leaf rust mite (Phyllocoptes pyrivagrans), Castanopsis witches’ broom mite (Aceria kadonoi), Retusa fringe tree malformation mite (Aceria sp.) calls for a greater awareness of them in Korea. Besides, the eriophyoid mites from ornamental trees get to known to public, since the trees are planted along a street. Information on eriophyoid mites in Korea is often difficult to obtain. This was mainly due to the lack of taxonomic works done in Korea. Furthermore, some records on eriophyoid mites are not taxonomically based but just adopted neighboring countries’ records. Their original descriptions are frequently inadequate with focusing on the ecological aspects rather than taxonomic ones. So, some species including Aceria species from Lycium chinensis, in the light of recent knowledge of eriophyoid taxonomy, should be renamed and reclassified. Until now, more than 38 species in 17 genera of the family Eriophyidae have been reported in Korea, which is still relatively small number compared with those in neighboring countries; China (197 spp., in 60 gen), Japan (47 spp., in 19 gen), and Taiwan (75 spp., in 41 gen). Furthermore, none of the other families (Phytoptidae and Diptilomiopidae) have known yet. There is little doubt that more species await discovery in Korea. Considering the geographic distribution patterns, only 7 species among 38 species of Korean eriophyids are endemic. A total of 23 Korean eriophyid species are shared with Japan, 12 species with China, 5 species with Taiwan, 7 species with Russia, and 19 species with USA. It shows that the Korean eriophyid fauna seems to be similar to the Japanese fauna zoogeographically, and more cooperation between Japanese and Korean taxonomists is continuously needed in the eriophyoid field. On the other hand, more endemic and taxonomically important species are expected to be found in the Korean peninsular, since the eriophyoid mites is highly host specific and Korean peninsular is one of the most interesting areas with intense speciation processes. The upland and mountainous landscape (constituting 80% of the peninsula) favours the existence of multiple isolated habitats. The Korean peninsula is characterised by a high level of endemism among the species of higher vascular plants. Out of 2,898 plant species 407 are endemics (14%), including 224 endemic species in the southern and 107 endemic species in the northern part of the peninsula.

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.

Some solitary wasps and bees exhibit peculiar structures, i.e., acarinaria, which are invaginated chambers harbouring certain mite species for transfer to brood cells of hosts. Acarinaria have long been considered morphological adaptations that evolved to securely transfer beneficial mites into nests but there is little compelling evidence to support this hypothesis. The dispersal deutonymphs of the mite Ensliniella parasitica are housed in acarinaria of the host A. delphinalis during phoresy. The mite life cycle has been investigated in detail; the deutonymphal mite using acarinaria invades into a host cell during wasp oviposition, the tritonymph feeds on heamolymph from lepidopteran prey, then adults from the juvenile host, the female begins laying eggs on the host after the host pupates, and larvae and protonymphs acquire nutrition from the pupa, developing into deutonymphs by host eclosion. Although totally parasitic to the juvenile host throughout its life cycle, the mite did not negatively affect on the host. Nests were sometimes infested with other natural enemies, which included a parasitoid wasp (Melittobia acasta), a kleptoparasitic fly, and unknown pathogens. When the parasitoid and adult mites co-existed in a host cell, we found that either all mites or all parasitoids died. A single adult parasitoid (female) and adult mites were placed in transparent acrylic tubes containing a single prepupal host. In some cases, the parasitoids harbouring mites eventually died. However, in other cases, the parasitoid counterattacked mites by possibly biting them on their dorsum. This experiment demonstrated that the probability that the parasitoid was killed depended on the number of mites. Although mutualisms to protect a partner are common, this wasp-mite interaction is exceptional, because the mite is non-predacious and much smaller in body size than the enemy but protects the host wasp.

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.

Survival rate and development of the two spotted spider mite, Tetranychus urticae are decreased by UV-B irradiation (Otsuka and Osakabe, submitted). This is considered to be a reason why this mite prefers lower leaf surfaces host plants. On the contrary, the citrus red mite, Panonychus citri is known to remain on upper leaf surfaces of host plants. Such difference in the distribution was assumed to depend on the difference in UV resistance. Hatchability of P. citri eggs was decreased by UV-B irradiation, yet their eggs were more protected from the UV-B irradiation in company with T. urticae. Eggs of P. citri are reddish, while those of T. urticae are white. To test whether the reddish color invest UV resistance in eggs, pale white eggs of albino strain and reddish eggs of wild type of P. citri were simultaneously irradiated by UV-B. Reddish eggs of wild type showed higher resistant to the UV-B irradiation than the pale-white eggs of albino strain. For the next step, the wild type and the albino eggs of P. citri under UV opaque film (-UV) or under UV transparent film (+UV) were exposed to solar irradiation. Hatchability of albino eggs was signifycantly lower than that of wild type eggs under the + UV condition. Under UV –, both eggs showed higher hatchability than under UV+ conditions. From these results, the wild type eggs of P. citri were likely to have some mechanism protecting itself from ambient UV irradiation, and the red pigment possibly act as a shield againt solar UV radiation. F1 female proceeded by reciprocal crosses between the wild type and the albino strain exhibited reddish body color in their adult stage, indicating that the albino was recessive. Notwithstanding, F1 eggs from the crosses between albino female and wild type male were pale white. After hatching, the F1 larvae also exhibit pale white body color, then the females turned to reddish at their first quiescent stage. F1 progeny from the crosses between wild type female and albino male were all reddish during egg to adult stage. These revealed that the color of eggs and also larvae were conferred as a maternal effect (: eggs of P. citri might be protected by the red pigments as the first gift of their mother.)

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.

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.

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.

The life cycle of ticks is characterized by alternate off-host and on-host conditions. The life span is estimated at several years and most ixodid ticks spend more than 95% of their life off the host. They seem to have a unique strategy to endure the off-host state for a long period. By electron microscopy, isolation membrane-, autophagosome- and autolysosome-like structures were found in the midgut epithelial cells of unfed ticks. Therefore, we focused on autophagy which is well-conserved from yeast to higher eukaryotes and induced by starvation. We have identified homologues of autophagy-related (ATG) genes (ATG3, ATG4 and ATG8) from cDNA libraries of the 3-host tick Haemaphysalis longicornis. Each expression profile of H. longicornis ATG (HlATG) genes and HlAtg proteins at the stages of nymph and adult were examined by real-time PCR and immunoblotting. Moreover, autophagy is known to be induced by inactivation of target of rapamycin (TOR), a phosphatidylinositol kinase. To examine the effect of TOR function on the expression of HlAtg protein(s), rapamycin, a specific inhibitor of the signal transduction mediated by TOR, was injected to unfed adults. It was revealed that the expression of HlAtg protein(s) was enhanced in response to the rapamycin. This result indicates that tick have the nutrient-sensitive TOR signaling pathway which regulate autophagy.

Antimicrobial peptides represent an essential alternative first line of defense. Naturally occurring molecules associated with the innate immune system in disease-bearing vectors such as mosquito, tick could be the target for searching more potent and effective agents to combat against the pathogens resistant to conventionally used antibiotics. Recently, we explored expression of a defensinlike peptide, longicin from the hard tick Haemaphysalis longicornis. Longicin and one of its synthetic partial analog (P4) displayed antimicrobial/fungicidal/parasiticidal activity and, therefore, proposed to be a chemotherapeutic compounds against tick-borne disease organisms. Structural characterization of antimicrobial peptides is very important to understand the peptide activity. In addition, harmful side effects such as lysis of red blood cells or cytotoxicity towards mammalian host cells commonly associated with antimicrobial peptides as potential therapeutic agent should also be elucidated. In this study, we analyzed some structural features using bioinformatics tool, CD Spectroscopy, and also determined cytolytic activity of P4 peptide. According to the chemicophysical characteristics, the P4 is suggested to be a cationic peptide with hydrophobic and amphipathic character. The predicted secondary structure indicated the existence of β-sheet which was also observed in modelled tertiary structure. CD spectroscopy results also revealed the existence of a β-sheet and changes of helical content in the presence of membrane-mimic condition. These structural observations on P4 suggest that the antimicrobial activity could be due to the well developed β-sheet. In addition, sequence homology search showed that antimicrobial molecule identified in other ticks and in organisms have the P4 analogous domain at their C-terminal, which indicates P4 as a conserved antimicrobial domain. The peptide P4 also showed less cytolytic activity against various cell lines or erythrocytes of various species. The data presented here strongly suggests that the peptide P4 could be developed as future therapeutic agent against tick-borne microorganisms.

Blood feeding tightly regulates the reproductive cycles in ticks. Vitellogenesis and nutritional signaling are a key event in the tick reproductive cycle. Here we report the identification of a Haemaphysalis longicornis GATA factor, (HlGATA), which is synthesized after a blood meal and acts as a transcriptional activator of vitellogenin (Vg). HlGATA shares structural similarity with other GATA factors of invertebrates and vertebrates. Tick GATA mRNA accumulated in the fat body and midgut prior to blood feeding. However, translation of GATA was activated by blood feeding because the GATA protein increased dramatically in engorged females. RNA interference (RNAi)-mediated knock down of GATA transcript resulted in a significant inhibition of Vg expression and effectively disrupts egg development after blood meal in engorged tick. In addition, HlGATA translation was inhibited by RNAi-mediated knock down of S6 kinase. These experiments have revealed that the GATA factor, which is the specific transcriptional activator of Vg gene, represents important molecule for tick reproduction.

A full-length sequence of a thrombin inhibitor (designated as hemalin) from the midgut of pathenogenetic Haemaphysalis longicornis has been identified. Sequence analysis shows that this gene belongs to a Kunitz-type family, containing two Kunitz domains with high homology to boophilin, the thrombin inhibitor from Rhipicephalus (Boophilus) microplus. The recombinant protein expressed in insect cells delays bovine plasma clotting time and inhibits both thrombin-induced fibrinogen clotting and platelet aggregation. A 20-kDa protein was detected from the midgut lysate with antiserum against recombinant hemalin. The gene expresses at all stages of the tick except for the egg stage and mainly in the midgut of the female adult tick. Real-time PCR analysis shows that this gene has a distinctly high expression level in the rapid bloodsucking period of the larvae, nymphs, and adults. Disruption of the hemalin gene led to a 2-day extension of the tick blood feeding period, and 27.7% of the ticks did not successfully complete the blood feeding. These findings indicate that the newly indentified thrombin inhibitor from the midgut of H. longicornis might play an important role in tick blood feeding.

Eczema due to contact allergy is usually produced by simple chemicals with the molecules less than 500 KD. A total of 100 cultivated house dust mites (HDM) were extracted with their lipid components in hexane, and they were analyzed by mass measuring gas chromatography. The same components were mixed in petrolatum at 5% or less, and patch tested using Finn Chambers, and the results were read by ICDRG standards. α-Acaridial, contained in Tyrophagus putrescentiae, turned out to have been a primary sensitizer, and could make prurigo reactions. Geranial, a main lipid component in dermatophagoides, showed positive rates at 58.8% at 5% concentration in atopic dermatitis and was expected to cross react to geraniol in cosmetics and soaps. It means that when one is sensitized by HDM, eczema can be provoked and maintained by the usage of ordinary soaps, shampoos and cosmetics, containing geraniol.

Female ticks require a blood meal for vitellogenesis to occur. Vitellogenin (Vg), a precursor of yolk protein, is essential for egg development and Vg synthesis appears to be regulated by ecdysteroids in ticks. To better understand the regulation of Vg synthesis in ticks, the Vg gene was identified from Orinthodoros moubata. OmVg is composed of 5,502 bp encoding a 1,834 aa protein with Vg specific characteristics. OmVg gene showed the highest homology with the hard tick Dermacentor variabilis and was included in the same clade of a phylogenetic tree as the hard tick and crustacean Vg genes. OmVg gene expression was observed in females but not in nymphal stages and during molting. Both mated and virgin females showed OmVg expression approximately 3 days after engorgement. However, as time passed, mated females showed significant increases in OmVg expression whereas virgin females didn’t. OmVg expression is thought to be regulated by ecdysteroids functioning through a complex with an ecdysteroid receptor (EcR) and retinoid X receptor (RXR). EcR and RXR expression increased in both mated and virgin females soon after engorgement. However, ecdysteroid titer only increased in mated females indicating a high titer of ecdysteroids in mated females up-regulates OmVg expression. The OmVg gene was expressed in the fat body and midgut of O. moubata. Further studies are underway to determine other factors that may explain differences between mated and virgin O. moubata females. Understanding the regulation of reproduction in ticks may lead to the development of better mechanisms for controlling ticks and preventing the spread of tick vectored diseases.

The whitefly Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) is one of the most important agricultural pests in Japan, that causes retard of plant growth and sooty moulds through excreted honeydew by direct sucking of pholoem sap, and additionally transmits several kinds of plant virus. B. tabaci consists of more than 20 biotypes which possess different ecological or physiological characters but cannot be distinguished from others morphologically. In Japan, exotic B and Q biotypes are the common pests of vegetables, flowers and ornamental plants. B biotype, the silver-leaf whitefly, was first recorded in Aichi Prefecture, Tokai region, in 1989 and expanded its distribution to almost all part of Japan, except for the northern area, within several years. Q biotype was recently found in Hiroshima Prefecture, Chugoku region, in 2004 and is still expanding the distribution in our country. Indigenous B. tabaci biotypes also exist in the southwestern part of Japan: JpL biotype was recorded in Honshu, Shikoku, Kyushu Islands and Nauru biotype was found in Amami and Ryukyu Islands. Although the host plants of these indigenous biotypes include some agricultural crops, these insects are not important as agricultural pests. The most serious problem in vegetable cultivation caused by B. tabaci is an intensive epidemic of the tomato yellow leaf curl disease (TYLCD) which leads to a large yield loss of tomato production in green houses. TYLCD distributes worldwide and it was found in Aich and Sizuoka Prefectures, Tokai region, and Nagasaki Prefecture, Kyushu region, simultaneously in 1996. The distribution of TYLCD expanded mainly in the western part of Japan for several years after its first finding, but recently TYLCD started to occur also in the eastern part of Japan, Kanto and Tohoku regions. Tomato yellow leaf curl virus (TYLCV), a pathogen of TYLCD, is transmitted by B or Q biotype of B. tabaci in a persistent manner. Although an effective control of B. tabaci is essential for decreasing of TYLCD outbreaks in tomato green houses, it is quite difficult to control these whiteflies only by the spraying of chemically synthesized insecticides due to their insecticide resistance. Especially, Q biotype shows a high level of resistance to pyriproxyfen and neonicotinoid insecticides. To avoid the development of insecticide resistance in B. tabaci, we are trying to combine some different control methods, for example, use of a fine mesh screen to prevent the invasion of vector insects, use of the physical-coating or microbial insecticides with the chemically synthesized insecticides to prevent the reproduction of vector insects, closing and steaming of a green house at the end of tomato cultivation to kill vector insects and prevent their escape from there, as an integrated pest management (IPM) system for B. tabaci and TYLCD control. We are also breeding TYLCV resistant varieties of tomato and considering how to use these varieties effectively.