This study was performed to analyze the sugar contents from six kinds of plant and investigate their effect on the life span of ggot-mae-mi, Lycorma delicatula. Part of plants were methanol extracted from host plants such as Ailanthus altissima, Vitis vinifera and non-host plants such as Malus pumila, Pyrus calleryana, Hibiscus syriacus, and Pinus densiflora, and concentrated the water layer and then analyzed the sugar contents using HPLC. Ailanthus altissima existed high in sugar contents and followed by Fructose>Glucose, Vitis vinifera was analyzed by an order of Glucose>Fructose>Maltose>Sucrose>Rhamnose; Malus pumila was as Glucose>Fructose; Pyrus calleryana was as Glucose>Unknown>Fructose; Hibiscus syriacus was as Sucrose>Glucose; Pinus densiflora was as Fructose>Glucose>Sucrose. A parafilm bioassay was used to investigate the longevity of L. delicatula nymphs to the sugar contents. Nymphs of L. delicatula was lived as long as 13.1 days in 5% Sucrose solution, but lived as short as 6.0 days in 5% Glucose solution. When provided with only water, L. delicatula lived for 5.4 days. Life span to the each sugar contents were longer lived in an order of Sucrose>Fructose>Rhamnose>Maltose>Glucose. As investigated the life span of L. delicatula nymph according to the combination of sugar contents founded in original plants were lived longer in 5% sugar combination solution of Ailanthus altissima. Analyzed original sugar contents from Malus pumila, Pyrus calleryana, L. delicatula was lived as 7.8, and 7.1 days, respectively, comparing to the Hibiscus syriacus, and Pinus densiflora lived as 6.0, and 4.7 days, respectively. This result were judged that sugar contents affected on choosing the host plants.

This study was performed to compare the host preference, survivorship and feeding behavior using EPG against ggot-mae-mi, Lycorma delicatula against seven plants such as Ailanthus altissima, Vitis vinifera, Malus pumila, Pyrus calleryana, Hibiscus syriacus, and Pinus densiflora. In host preference. L. delicatula was most preferred the Ailanthus altissima, Vitis vinifera and was not preferred the other plants. Survival rate of 3rd Nymph was recorded from Ailanthus altissima, Vitis vinifera as 15.0, and 15.4 days, respectively, it showed longest period. However, Malus pumila, Pyrus calleryana, Hibiscus syriacus, were survived within 6 days and Pinus densiflora was within 5 days. Moreover, L. delicatula was survived within 2 days to the three kinds of fruits. Ecdysis rate from 3rd to 4th nymph also high from Ailanthus altissima, Vitis vinifera as 63.3, 63.0 % and the order was followed as Malus pumila(17.7%) > Pyrus calleryana(9.3%) > Hibiscus syriacus(7.8%) > Pinus densiflora(5.9%). Especially, ecdysis rate was recorded 0% to the three kinds of fruits. Feeding behavior was analyzed using EPG and compared the differences their waveform from seven kinds of plants and three kinds of fruits. Non-probing time was short in host plants, reversely, Phloem-feeding time was recorded longer in Ailanthus altissima, Vitis vinifera as 45.7 and 13.7 min, respectively. And other plants and fruits were not showed feeding behavior.

Simple and high efficiency green phosphorescent devices using an intermixed double host of 4, 4', 4"-tris(N-carbazolyl) triphenylamine [TCTA], 1, 3, 5-tris (N-phenylbenzimiazole-2-yl) benzene [TPBI], phosphorescent dye of tris(2-phenylpyridine)iridium(III) [Ir(ppy)3], and selective doping in the TPBI region were fabricated, and their electro luminescent characteristics were evaluated. In the device fabrication, layers of 70Å-TCTA/90Å-TCTA[0.5TPBI0.5/90Å-TPBI doped with Ir(ppy)3 of 8% and an undoped layer of 50Å-TPBI were successively deposited to form an emission region, and SFC137 [proprietary electron transporting material] with three different thicknesses of 300Å, 500Å, and 700Å were used as an electron transport layer. The device with 500Å-SFC137 showed the luminance of 48,300 cd/m2 at an applied voltage of 10 V, and a maximum current efficiency of 57 cd/A under a luminance of 230 cd/m2. The peak wavelength in the electroluminescent spectral and color coordinates on the Commission Internationale de I'Eclairage [CIE] chart were 512 nm and (0.31, 0.62), respectively.

The green rice leafhopper, Nephotettix cincticeps is an insect vector which transmits virus diseases of rice plant causing severe damage to the rice and its damage both quality and yield of rice. Survival rate of overwintering N. cincticeps in Alopeculus acquadis among 15 species of the winter crops and weeds was 37.8% and its most preferred. Density of N. cincticeps in environment-friendly agriculture area which cultivated Astragalus sinicus as a green manure crop in winter season increased in number wintering pass in Alopeculus acquadis and Astragalus sinicus as host plants, because of control of N. cincticeps was not enough in the previous year. Survival rate of N. cincticeps was higher mainly in habitation mixed with rice straw, Astragalus sinicus and Alopeculus acquadis as winter habitation. It warmed due to the effect of the keeping warmth inside of a rice paddy field and the bank around a rice field covered with rice straw or Astragalus sinicus. Also, habitation conditions were optimal for survival because of growing Alopeculus acquadis as the major host plant of N. cincticeps in that place.

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.

An endoparasitoid wasp, Cotesia plutellae, parasitizes larvae of the diamondback moth, Plutella xylostella, with its symbiotic polydnavirus, C. plutellae bracovirus (CpBV). This study analyzed the role of Inhibitor-kB (IkB)-like genes encoded in CpBV in suppressing host antiviral and antimicrobial responses. Identified eight CpBV-IkBs are scattered on different viral genome segments and showed high homologies with other bracoviral IkBs in their amino acid sequences. Compared to an insect ortholog (e.g., Cactus of Drosophila melanogaster), they possessed a shorter ankyrin repeat domain without any regulatory domains. The eight CpBV-IkBs are, however, different in their promoter components and expression patterns in the parasitized host. To test their inhibitory activity on host antiviral response, a midgut response of P. xylostella against baculovirus infection was used as a model reaction. When the larvae were orally fed the virus, they exhibited melanotic responses of midgut epithelium, which increased with baculovirus dose and incubation time. Parasitized larvae exhibited a significant reduction in the midgut melanotic response, compared to nonparasitized larvae. Micro-injection of each of the four CpBV genome segments containing CpBV-IkBs into the hemocoel of nonparasitized larvae showed the gene expressions of the encoded IkBs and suppressed the midgut melanotic response in response to the baculovirus treatment. When nonparasitized larvae were orally administered with a recombinant baculovirus containing CpBV-IkB, they showed a significant reduction in midgut melanotic response and an enhanced susceptibility to the baculovirus infectivity. The transiently expressed CpBV-IkB3 inhibited expression of hemolin, but did not those of lysozyme and cecropin in P. xylostella, while both lysozyme and cecropin were inhibited in the treated Spodoptera exigua. When the recombinant AcNPV was mixed with Bacillus thuringiensis subsp. kurstaki (Bt), the bacterial pathogenicity was significantly enhanced in a dose-dependent manner, compared to a Bt mixture with an AcMNPV recombined with an enhanced green fluorescence protein gene.

Upon oviposition, parasitoid wasps inject their eggs along with venom, teratocytes and polydnavirus (PDV) on the host. Among these parasitic factors, PDVs are known to suppress the host immune system and utilize the host translational mechanisms allowing the juvenile parasitoid to develop. Polydnavirusencoded genes can selectively inhibit host translation and still use the translation machinery of the host to synthesize their own proteins. In this study, we utilize a proteomic approach involving two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) that couples isoelectric focusing (IEF) and SDS-PAGE to resolve complex protein mixtures that results from the parastization of Cotesia plutellae on the lepidopteran host, Plutella xylostella. We specifically analyze the changes in protein synthesis using this technique after treatment of HTIFs that has been previously identified on C. plutellae. The difference in protein profile due to parasitization was confirmed by in vitro translation assay using rabbit reticulosyte lysate.

The soybean aphid, Aphis glycines Matsumura 1917, is well known as a soybean pest in the world. Recently, it has been introduced to North America causing serious damage in U.S. As a cooperative research with USDA-ARS, we have investigated A. glycines in soybean fields, and also examined the colonies on the overwintering host Rhamnus davurica in order to find its natural enemies. It was generally reported that A. glycines has host alternation between the soybean, Glycine max (summer host) and the Dahurian buckthorn, Rhamnus davurica (winter host) in East Asia. However, it was very difficult to identify the soybean aphid, A. glycines, from R. davurica due to the co-existance of at least three Aphis species and the seasonal polymorphisms of each species (e.g, gynopara, ovipara, and male). For species identification, we tested 3 molecular markers, mitochondrial COI, COII, and nuclear EF1α, for 14 collected samples (7 samples from G. max and 7 samples from R. davurica). As a result, we found two different species, A. gossypii and other Aphis sp., are mixed together with A. glycines on R. davurica. We report the biology of A. glycines in Korea, and present species identification using molecular phylogenetic approach.

Swallowtail butterfly’s (Papilionidae) family is a large group including at least 550 species in the world, one of the most evolved butterfly families, and selects many special plants as a host plant. Many scientists have studied on the mechanism for host selection by swallowtail butterflies and many results including attractant, ovipositional stimulant, and feeding stimulant in each host plant have been reported. However, most of the reports are related to Papilinonini and Troidini genus and not to Graphiini genus. The reason why there are few reports about this genus is based on their nature. That is, this genus butterflies, especially common bluebottle, Graphium sarpedon, are very nerves and rearing for successive generations is difficult in the laboratory, emergence-adult never laid their eggs on the host plant and so on. We, therefore, have tried to isolation and identification of attractant, feeding stimulant, and ovipositional stimulant in the camphor tree to the common bluebottle, G. sarpedon.

Paromius exiguus (Distant) has caused serious damage by pecky grains around Gimpo paddy fields in 2001. We conducted field and laboratory studies to determine the seasonal occurrence and age distribution of P. exiguus on the three major host plants. The overwintering P. exiguus was found mainly on the basal part of gramineae weeds in various localities. After overwintering, in mid-May, the adults aggregated on the grain parts of Imperata cylindrica, laid their eggs and nymphs developed into adults on the same host plants. By the time, the Calamagrostis epigeios colony had newly occupied I. cylindrica areas, the nymphs and adults of first generation had already moved to the second host. The second generation of P. exiguus, after having completed its life cycle on C. epigeios, the newly emerged adults migrated to the rice plants and other gramineae weeds in early August. Afterwards, they complete its third generation cycle where they can move to the overwintering site again. P. exiguus has the five nymphal stages and each nymphal stage could be determined by head or prothoracic width. On the I. cylindrica and O. sativa hosts, the age distribution of P. exiguus showed a simple structure as each stage ratio increased stepwise with time. But in case of C. epigeios, as the newly emerged adults and immature nymphs continuously migrate after a month from the I. cylindrica, the age structure became remarkably complex. The peak nymphal density was observed when the ratio of third and forth instar was the highest in the population. The finding about the specific age structure on each generation of the insect would be very useful in control decision making on the major host plants. It is also important to consider the host"s specificity to pesticide sensitivity in relation to various nymphal stages.

The water mites are distributed widely through ponds, lakes and mountain streams. In part of their life cycle, larvae of water mites typically attach on adult aquatic insects including hemipterans, odonates, coleopterans, trichopterans, ephemeropterans, plecopterans and dipterans. Most of the information on hostparasite interactions comes from studies of lentic mites and insects, while relatively little is known about the relationships between lotic mites and insects. The purpose of this study is to elucidate the host-parasite interactions between lotic water mite larvae and host insects in mountain streams. We investigate mite attachment on aquatic insects collected at mountain streams in Kanagawa and Shizuoka Prefectures, Japan. Aquatic insects were collected by light-trap and hand-sweeping from May to August 2008. Aquatic insects were identified to species or genus. The parasitic nature of mite larvae on aquatic insects was examined. The distribution of water mite larvae on host insects was analyzed using the Chi Square Test. As a result, a total of 1716 specimens of aquatic insects representing Megaloptera, Trichoptera, Ephemeroptera, Plecoptera and Diptera were collected. Mites were associated with 31.2% of the total number of aquatic insects. Mite larvae in the genus Stygothrombium were associated with Plecoptera. Protzia larvae were associated with Trichoptera and Diptera. Stygomomonia larvae were associated with Trichoptera. Protzia larvae showed a preference for abdomen of Wormaldia sp. [Trichoptera] (P<0.0001, χ²= 133.3631). Protzia larvae however, showed a preference for prothorax of Antocha sp. [Diptera] (P<0.01, χ²=18.3077). Stygomomonia larvae showed a preference for mesothorax and abdomen of Stenopsyche marmorata [Trichoptera] (P<0.0001, χ²=1147.857). From these results, it is considered that mite larvae show certain host preferences for aquatic insects as well as site preferences for the body parts of host insects.

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.

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.

In many host-parasite interactions, intraspecific competition among host could have a significant role to the host-parasite population dynamics, yet so far a few studies has been reported theoretically and experimentally(ex. Umbanhowar and Hastings, 2002). We examined the effect of larval competition using a stage-structured matrix model with parameters estimated from the Plodia interpunctella-Bracon hebetor and Sitophilus zeamais-Aniopteromalus calandrae experimental system. The maize weevil population showed a typical growth pattern of populations with contest type competition. After introduction of A. calandrae to the system, maize weevil population was dramatically decreased to be extinct. In contrast, the Indian meal moth population showed a typical pattern of scramble type competition. Introduction of B. hebetor to the system induced higher moth density and longer persistence of the Indian meal moth population than that in the maize weevil system. These results seem to be caused by differences in intraspecific competition between Indian meal moth and maize weevil. The applications of these results should be considered in biological control of Indian meal moth.

The paternal sex ratio (PSR) chromosome is considered as an extremely selfish genetic element. It has only been found in the two hymenopteran insects- Nasonia and Trichogramma- with haplodiploid sex determination. When an egg is fertilized by sperm bearing PSR, the paternal genome is destroyed by PSR soon after fertilization resulting in haploid restoration and the egg develops into a male with only the maternal genome and PSR itself. Recently PSR is paid much attention, since it may be used for controlling haplodiploid pests. PSR can be successfully transferred from its natural host, T. kaykai to the novel host, T. deion. In the two hosts another sex ratio distorter, Wolbachia, is found. Wolbachia is a cytoplasmically inherited bacterium that induces parthenogenesis in this genus resulting in female offspring production without fertilization. The transmission efficiency of PSR in T. deion is lower than that in T. kaykai and is negatively influenced by the Wolbachia infection. The results show that 1) there is a negative host genetic background effect on the transmission of PSR in the novel host, 2) the transmission efficiency becomes even lower, when PSR males are infected with Wolbachia. The results imply that complex interactions among the bacterium, PSR and the species specific genetic background.

Trissolcus nigripedius Nakagawa and Telenomus gifuensis Ashmead (Hymenoptera: Scelionidae) are solitary egg parasitoids of Dolycoris baccarum L. (Hemiptera: Pentatomidae), a polyphagous seed-sucking bug of agricultural crops. Field examinations revealed that the two parasitoids are the most common species, but only a single species emerge from a host egg mass. To explain this observation we tested two hypotheses of interspecific host discrimination and asymmetry in competitive interaction between the two parasitoids. When provided with host eggs pre-parasitized by each other, both Tr. nigripedius and Te. gifuensis parasitized 94 and 100% of the host eggs without interspecific host discrimination, respectively. Interestingly, from the multiparasitized eggs irrespective of oviposition sequence, progeny of Te. gifuensis always survive better than Tr. nigripedius. Te. gifuensis is superior in immature competition probably due to shorter egg incubation period, hence progeny of Te. gifuensis become first instar faster than that of Tr. nigripedius. However, adult Tr. nigripedius is always superior competitor in possessing and guarding the host eggs even after oviposition against Te. gifuensis. Therefore, the asymmetry in competitive interaction between Tr. nigripedius and Te. gifuensis may explain the emergence of a single species from a host egg mass in the field in spite of no interspecific host discrimination.