The greenhouse whitefly Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae) is a phloem-feeding pest that causes serious damages in vegetables and ornamental crops by direct feeding and causing diseases such as sooty mold. For the better management of T. vaporariorum, within-greenhouse and -plant distribution of this pest was investigated in strawberry greenhouses in Andong. Ten strawberry plants for each category were randomly selected and examined. Adults per plant was recorded by visual observation, and eggs and nymphs per trifoliate leaf were counted under microscope. Adult, egg, and nymph populations were all more abundant in border rows than in middle rows. The number of nymphs were found more in lower canopy in both border and middle rows, but egg density was higher in upper canopy of border plants. No correlation was found between sticky trap count and population density on plants. These informations would be important for the development of efficient monitoring and control measures of greenhouse whitefly.
This study compared the development, reproduction, and DNA damage in insecticide (acequinocyl, bifenazate, and etoxazole)-resistant (AR, BR, and ER) and -susceptible (S) strains of Tetranychus urticae by electron beam irradiation. When eggs were irradiated with 150 Gy, the egg hatching was completely inhibited in all strains. When nymphs were irradiated, their emergence rate was decreased with increasing doses of electron beam irradiation. When adults were irradiated, the longevity and the number of eggs was not affected at all target dose in all strains. However, hatchability of F1 generation was perfectly inhibited at 400 Gy in all strains. The DNA damage caused by electron beam irradiation was evaluated by an alkaline comet assay. These results suggest that electron beam irradiation induced abnormal development and reproduction in S, AR, BR, and ER strains of T. urticae.
The influence of three temperatures, 20℃, 25℃ and 35℃ and four relative humidities (RH), 30-35%, 50-55%, 70-75%, and 90-95% on oviposition and development of Callosobruchus chinensis (L.) (Coleoptera: Bruchidae) on azuki bean seeds was investigated. One day old five males and five females of C. chinensis were introduced to 30 gm azuki bean seeds for each combination of temperature and RH, and replicated ten times. The introduced adults were allowed to lay eggs for 72 hours. Temperature significantly influenced on oviposition with increased number of eggs at 30℃, relative humidity, however, had no effect on egg laying. Development time was affected by both temperature and relative humidity. Development time was shortest at 30℃ and 70-75% RH. Adult emergence success rate was affected by both temperature and RH; increased level of temperature and RH increased emergence rate of adults. The results suggest that C. chinensis is much likely to cause greater damage to azuki bean seeds stored at 30℃ and 70-75% RH.
In insect exoskeleton/cuticle, structural cuticular proteins (CPs) and the polysaccharide chitin are the major components of the procuticle. CPs are cross-linked by quinones or quinone methides produced by the laccase2 (Lac2)- mediated oxidation of N-acylcatechols. We reported that two major CPs, TcCPR27 and TcCPR18, belong to the CPR family that contain the RR-2 consensus motif (Rebers & Riddiford), are essential for formation and stabilization of the rigid cuticle of Tribolium castaneum adults. In this study, we characterized and investigated functions of the third most abundant protein, TcCP30, in extracts of elytra. TcCP30 cDNA encodes a protein with 171 amino acid residues containing a putative signal peptide. Unlike TcCPR27 and TcCPR18, TcCP30 mature protein lacks an RR motif, with a very unique amino composition, 36% Glu, 21% His, 20% Arg and 16% Gly. TcCP30 gene is highly expressed right before and after eclosion (in 5 d-old pupae and 0 d-old adults). Immunohistochemical studies revealed that TcCP30 protein was present in rigid cuticle such as elytra and ventral abdomen but not soft cuticle such as hindwings and dorsal abdomen of adult T. castaneum. Injection of dsRNA for TcCP30 into late instar larvae had no affect on larval and pupal growth and development. However, the subsequent pupal-adult molt, more than 50% adults were unable to shed their exuvium and died entrapped in their pupal cuticle. In addition, the resulting adults exhibited wrinkled, warped and split elytra. TcCP30-deficient adults could not fold their hindwings properly because probably due to the malformed elytra. These results indicate that TcCP30 is critical for formation of rigid adult cuticle as well as development and growth of T. castaneum.
Helicoverpa armigera Hübner (Lepidoptera: Noctuidae), is an economically important and polyphagous pest, which harms various kinds of ornamental plants and flowers. The effects of electron beam irradiation of six level between 50 and 350 Gy on egg (24-48 h old), larval (4th-5th instar), and pupal (7-d old for female, 5-d old for male) development and on adult (1-d old) reproduction in H. armigera were tested to identify a potential quarantine treatment dose. Increased doses of irradiation on eggs decreased egg hatchability, pupation and adult emergence and increased period of larvae. ED99 values for inhibition of hatching, pupation and emergence were 460.6, 236.9 and 197.8 Gy, respectively. When larvae were electron-beam irradiation treated ,at 280 Gy and above, no pupa was observed. ED99 values for inhibition of pupation and emergence were 265.6 and 189.6 Gy, respectively. Electron beam radiation on pupa did not completely inhibit adult emergence. ED99 value for inhibition of emergence was 1241.9 Gy. When adults were irradiated, fecundity was not affected. However, F1 egg hatching was completely inhibited at the dose of 350 Gy. ED99 value for inhibition of emergence was estimated at 366.5 Gy. Our results suggest that electron beam irradiation could be recommendable as alternative to MB and as a phytosanitary treatment for quarantine. The dose of 211 Gy is suggested as a potential quarantine treatment dose for H. armigera egg and larva.
Insect cuticle is a first physical barrier to protect their body from multifarious environments. Cuticle tanning (sclerotization and pigmentation) is a complex process involves hydroxylation of tyrosine to 3,4-dihydroxyphenylalanine (DOPA), decarboxylation of DOPA to dopamine, N-acylation of dopamine to N-acetyldopamine (NADA) or N-β-alanyldopamine (NBAD), oxidation of NADA and NBAD to their corresponding quinones, and reactions between the quinones or quinone derivatives with cuticular proteins (CPs) resulting in protein cross-linking. N-acetyltransferase (NAT) catalyzes the conversion of dopamine to NADA whose covalent-linkage of CPs is correlated with colorless cuticle (β-sclerotization). In this study, we analyzed functions of TcNAT1 on cuticle tanning of adult Tribolium castaneum by RNAi. Injection of dsRNA for TcNAT1 (dsTcNAT1) had no affect on animal development and growth. However, some of the resulting adults (~70%) showed split elytra that could not cover their abdomen, resulting in improper folding of their hindwings. Interestingly, body color of the mature adults was darker than that of control dsTcVer-treated adults because probably due to the buildup of abnormally high levels of dopamine, which is used for dopamine eumelanin pigment synthesis (black pigment). On elytra and hindwings of these adults, darker pigments were observed around the sensory bristles located at the intervein regions, suggesting that NADA mediated β-sclerotization is occurred in these regions. Similarly, darker pigment was evident at veins of the hindwings of TcNAT1-deficient adults. These results suggest that TcNAT1 plays important roles in cuticle tanning of T. castaneum adult. To characterize enzymatic properties of TcNAT1, furthermore, recombinant TcNAT1 protein expressed in E. coli was purified by utilizing Ni-NTA affinity column chromatography. This work was supported by NRF (NRF-2012R1A2A1A01006467).
The genus Arboridia Zachvatkin belongs to the tribe Erythroneurini of the subfamily Typhlocybinae (Hemiptera: Auchenorrhyncha: Cicadellidae). A total of 69 valid species have been described in the Palaearctic and Oriental region. So far, seven species of this genus have been recorded in the Korean Peninsula.
In this study, we present two new species, Arboridia sp. nov. 1, Arboridia sp. nov. 2, and provide a key to the Arboridia species in the Korean Peninsula with biological information such as host plants and distributions.
We investigated the insect community along altitudinal gradient to gather basic data for distributional monitoring of insect species in the forest ecosystem. The investigation area was Seon-gaksan (Mt.) in Jinan-gun, Jeollabuk-do province, where the bucket-light trap and pit-fall trap for quantification were installed in Quercus vegetation at altitude of 300m, 600m and 900m. The field collecting was performed on May, July and September 2013 respectively. ANOVA analysis was conducted to analyze the significance between insect species along altitude using the collected insect community data. Analysis of variance (ANOVA) results showed statistically significant differences among ground-beetles and ants abundance with altitude as a response variable. Although we expected a distinct cluster with the difference of altitude at each study site, nonmetric multidimensional scaling (NMS) showed distinct clusters with the moth, ground-beetles, and ant assemblage at altitudinal increase and sampling month. In the result, a total of 309 species in 18 families of nocturnal moths were collected by bucket-light trap. The insects collected in pit-fall trap were ground-beetles with 196 individuals of 26 species and ants with 11,276 individuals of 14 species respectively.
As a result of investigation on the larvae attacking leaves of Eucommia ulmoides Oliv. and causing serious damage on the plant in Seoul, Chungnam and Jeonbuk Province in Korea during summer in 2013, Protegira songi Chen & Zhang of the family Noctuidae was identified. In this study, we report the host plants of it for the first time from Korea, with larval damage and taxonomic information by illustrating the characteristics of male and female genitalia. Also we will conduct to extract and analyse the DNA barcode for correct identification in forest pest monitoring in near future.
In this study, the following four species are reported for the first time in Korea: Diplopseustis perieresalis (Walker, 1859), Dolicharthria bruguieralis (Duponchel, 1833), Herpetogramma ochrimaculale (South, 1901), and Omiodes diemenalis (Guenée, 1854). All of the known species were enumerated with their available information including the collecting localities, host plants, illustrations of adults, and genitalia.
The Plant Extract Bank was established by 21 Century Frontier R&D Program. It has began selling a research plant extract samples to support many Korean scientists since 2001. The plant extracts were tested for insecticidal activities.
A total of 19,100 ethanolic and methanolic extracts of differentplant species from 23 nations including Costa Rica, Philippines, India and South Africa were evaluated for their larvicidal activities against Aedes aegypti, the major vector of dangue, dangue hemorhagic fever and yellow fever. The larval mortalities were observed 24h after treating the larvae to the extracts. At 500 ppm, 754 extracts showed >80% larval mortality in the 24h exposure. Among the extracts tested, the highest larval mortality was observed in the methanol extracts of Piper guianense, P. nigrum, P. mocropodum, P. sem-immersum, P. magen and P. pubicatulm.
Insects impact human health through vector-borne diseases and cause major economic loses through damaging crops and stored agricultural products. Insect-specific growth regulators (IGR) represent attractive control agents because of their safety to the environment and humans. Here, we report identification of plant compounds that are antagonists of the insect-specific juvenile hormone (PJHANs), using the yeast two hybrid system transformed with the mosquito JH receptor as a reporter assay. We show that these compounds act by inhibiting larval growth and reproduction in mosquitoes. We also demonstrate that PJHANs affect the JH receptor, Methoprene-tolerant (Met), by disrupting its complex with CYCLE, formation of which is required for mediating JH action. We isolated five diterpene secondary metabolites with JH antagonist activity from two plants, Lindera erythrocarpa and Solidago serotina. They are effective in causing mortality of mosquito larvae at relatively low LD50 values. Two of these diterprenes affect Met function, leading to reduction in expression of Met target genes and causing retardation of follicle development in mosquito ovaries.
Developing potent compounds counteracting JHaction (JH antagonists) would find a wider range of control applications. However, so far such JH antagonists have not been developed. Here, we report the discovery of potent JH antagonists in plants, which represents an innate resistance mechanism of plants against insect herbivores. These newly discovered plant JH antagonist compounds could be used as the starting material for developing novel insecticides.
Methyl bromide(MB) is a fumigant for quarantine and pre-shipment(QPS) that can eradicate target pests within short fumigation periods. However, MB, an ozone-depleting substance, is scheduled to be phased out in the second decade of this century. In contrast to MB alternatives for soil fumigation, there is no ideal alternative fumigant to MB for QPS of perishable commodities. It is important that all target insect pests are killed within a short fumigation time.
The citrus mealybug(Planococcuscitri), a problematicquarantine pest from Korea, was exposed to ethyl formate and phosphine for different times and to different concentrations of EF(0.0∼33.4 mg/L) and PH3(0.25∼1.0 mg/L) in small desiccators. The eggs showed more tolerance than the nymphs and adults. To control the eggs, they were treated with a mixture of EF and PH3 for 2 and 4-hr. The egg stage showed 100% mortality with EF:PH3(25.1:0.25, 16.7:0.5, and 16.7:1.0 mg/L) at 4-hr. Treatment with a mixture of EF and PH3 for 4-hr at 8°C can control all stages of the citrus mealybug.
Insect cuticle is a complex biocomposite material consisting of three major morphologically distinct layers, the waterproofing envelope, the protein-rich epicuticle and the chitin/protein-rich procuticle. Structural cuticular proteins (CPs) and the polysaccharide chitin are the major components of the exo- and endocuticular layers that comprise the procuticle. During cuticle tanning (sclerotization and pigmentation), CPs are cross-linked by quinones derived from the oxidation of catechols, resulting in hardening of the exoskeleton. However, the factors that lead to synthesis and assembly of cuticular regions with differing mechanical properties are not well understood.
To gain a better understanding of the development and differentiation of rigid cuticle, we performed transmission electron microscopic (TEM) analysis of elytral cuticle (highly sclerotized and pigmented forewing) from 2 d-old pupae to 9 d-old adults of the red flour beetle, Tribolium castaneum. In 2-3 d-old pupae, pupal cuticle separated from the underlining epidermal cells (apolysis), and outermost envelope and protein-rich epicuticle begun to form. A numerous horizontal chitinous laminae and vertical pore canals were evident in the procuticle of 4-5 d-old pupae. By one day after adult eclosion, less-compact horizontal chitinous laminae were deposited, followed by block-type cuticular layers with no horizontal laminae were formed by 9 days. These results will lead to a) a better understanding of insect cuticle formation, structure and mechanics, b) the potential for development of novel insect control agents that target cuticle physiology, and c) the production of biomimetic materials with physical properties like those of the insect exoskeleton for use in biomedical or other technological devices.
This work was supported by NRF (NRF-2012R1A2A1A01006467).
There are relatively few cases of classical biological control in Korea. During 1904 to 1905 the wooly apple aphid, Eriosoma langigerum, had been happen to invade into Korea from Japan together with imported seedling of apple and its damage spread to Jinampo near Pyoung-Yang City and it occurred all across the country by 1934. In 1934 a parasitic wasp, Aphelinus mali, was introduced and released to apple orchards and found established in nature. And it was the first case of classical biological control in Korea. Afterward couple of classical biological control programs against invaded pests were conducted mainly by the RDA with variable results. For example the orange scale, Ceroplastes rubens, and the Eggar which were successfully controlled by introduction Anicetus beneficus and Thecodiplosis pinico, respectively.
Biological control as a tactic of environmentally safer agriculture has not been widely accepted by farmers. In Japan integrated biological control with native natural enemies is rapidly developing for greenhouse vegetables, because of high prices of commercially mass-reared biological control agents. We have studied the effective use of natural enemies at farm level, focusing on generalist predators, although there are differences in using natural enemies for augmentation in greenhouses and conservation in open fields. Recently, however, insectary plants (crops) have been considered as a key component for enhancing natural enemies. We have examined the effectiveness of candidate insectary plants on natural enemies and implemented biointensive IPM with insectary plants at farm-level. Our recent study suggested that some herbs and crops are highly effective on improving the survival and reproduction of generalist predators. By growing such plants in vegetable greenhouses and open-fields, natural enemy populations could be enhanced and thus stably persist even after targeted prey populations are exploited. Moreover, insectary plants may result in a shift of IPM from level I to level II.
The aim of the present study was to compare two different serum-free media, modified synthetic oviduct fluid (mSOF) and modified potassium simplex optimization medium (mKSOM) containing 20% RD (RPMI1640 + DMEM, 1:1 v/v) (RD-mKSOM), for in vitro culture (IVC) of bovine embryos. After in vitro maturation and fertilization, the presumptive zygotes were cultured in two different serum-free conditions for 7 days and 9 days to evaluate blastocyst formation and hatching, respectively. Serum supplemented conventional CR2 medium was used as control. After 7 day of culture, there was no significant difference in cleavage and blastocyst formation rates among three groups (mSOF, 59.3 and 30.1%; RD-mKSOM, 65.0 and 41.5%; control, 51.6 and 38.0%, respectively). Hatching rate was significantly higher in control (69.0%) than other experimental groups (mSOF, 22.0%; RD-mKSOM, 39.5%) (P<0.0001 and P<0.001, respectively). Although both serum-free conditions showed lower hatching rates than serum-added control, in serum-free groups, RD-mKSOM showed significantly higher hatching rate than mSOF (P<0.001). In addition, one-step using RD-mKSOM may facilitate IVC procedure than two-step culture system. In conclusion, the results indicate that one-step RD-mKSOM is more suitable defined culture system for IVC of bovine embryos than two-step mSOF.
The objective of this study was to determine the best performing switchgrass (Panicumvirgatum L.) cultivar with three different seeding dates as a bioenergy source in Republic of Korea. Split-plot in time with three replications was performed and three switchgrass cultivars, Carthage (CT), Cave-in-Rock (CIR), and Forestburg (FB) were used in this experiment from 2009 to 2012. Plots were seeded on April 23, May 4, and May 13, 2009 and were harvested once in November each year. No fertilizer was applied to the field for the first year; however, in second and third years (June 2010 and May 2011, respectively), N, P2O5 and K2O fertilizers were applied in 67,45 and 90 kg ha-1, respectively. Soil pH (5.9) and climate condition including temperature (10.4∼17.5℃) and precipitation (89.4~109.8 mm month-1) were suitable for switchgrass cultivation. Total dry matter yields were higher in CT and CIR compared to FB and were 16.9, 15.9, and 4.5 ton ha-1, for CT, CIR, and FB, respectively (p<0.0001). The samples were analyzed for dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), crude fiber (CF), ether extract (EE), and ash. No significant differences in energy content (p = 0.96) and chemical composition among cultivars (p>0.05) were found. Seeding dates did not affect DM yield (ton ha-1), chemical composition and energy content significantly (p>0.05). Significant difference was observed for heights among CT, CIR, and FB (177.59, 169.98, and 94.89 cm, respectively, p = 0.0002). In conclusion, based on soil characteristics and climate condition in Korea compared to other countries, switchgrass can be cultivated successfully. Considering dry matter yield and energy content of these three cultivars of switchgrass CT and CIR adapted better to climate in Middle Eastern of Republic of Korea than Forestburg for bioenergy purpose.
교정제도는 최근 많은 변화를 겪었다. 이러한 변화들은 형량 감소에서부터 범죄자 교화 프로그램(rehabilitative program)의 변화까지 다양하며, 어떤 정책과 전략들이 가장 효과적이고 사회에 유익한지에 대한 연구조사를 바탕으로 이루어졌다. 미국 교도소 수감인원이 지난 40년동안 급격히 증가했고, 이러한 증가는 교도소의 과밀화뿐만 아니라 재소자들을 수감하는데 많은 세금이 필요하다는 이유에서 많은 변화를 필요로 하였다. 수감인원의 급속한 확산(epidemic of incarceration)은 교화와 교육, 징역형 등 현재 사법제도가 효율적인가에 대해 의문을 제기하는 사람들이 점점 늘어났다. 특히 약물사범(drug offenses)과 같은, 필요하다면 교화프로그램이나 벌금, 사회봉사, 보호관찰 등으로 대체할 수 있는 비폭력적인 범죄에 대한 의무적인 징역형에 관하여 비판이 많았다. 그 후 비폭력적인 범죄자들을 장기간 투옥시키는 것은 범죄를 다시 재발시킨다는 것을 연구를 통해 알아냈고 회전문처럼 수감자들이 들락날락 거리는 상황이었던 것이다. 아직 국가적으로는 갈 길이 멀지만 몇몇 주(States)는 수감인원 감소를 위해 징역을 대체할 방법 연구를 시작했고 약간의 성공적인 수치를 얻었다. 가장 철저하게 재소자들 수를 줄일 수 있는 방법은 교화를 통해 근본적인 범죄자들의 재범을 감소시키는 방법이다. 이를 통해 재소자 수는 감소하고 그에 따라 감옥으로 되돌아가는 것 대신 법을 지키는 시민으로써 사회로 복귀하게 된다. 교화방법은 어려운 도전이다. 사실 개개인들의 범죄는 법을 어기게 된 각자의 사연과 이유가 있기 때문에 그에 맞춰 교화프로그램과 교화프로그램이 필요한 재소자에게 사용 가능하도록 개선시키기 위해 논의 해야할 게 많다.
Curcumin is a widely used flavoring agent in food, and it has been reported to inhibit cell growth, to induce apoptosis, and to have antitumor activity in many cancers. Cisplatin is one of the most potent known anticancer agents and shows significant clinical activity against a variety of solid tumors. This study was undertaken to investigate the synergistic apoptotic effects of co-treatment with curcumin and cisplatin on human tongue SCC25 cells. To investigate whether the co-treatment efficiently reduced the viability of the SCC25 cells compared with the two treatments separately, an MTT assay was conducted. The induction and the augmentation of apoptosis were confirmed by DNA electrophoresis, Hoechst staining, and an analysis of DNA hypoploidy. Western blot, MMP and immunofluorescence tests were also performed to evaluate the expression levels and the translocation of apoptosis-related proteins following the co-treatment. In this study, following the co-treatment with curcumin and cisplatin, the SCC25 cells showed several forms of apoptotic manifestation, such as nuclear condensation, DNA fragmentation, reduction of MMP, increased levels of Bax, decreased levels of Bcl-2, and decreased DNA content. In addition, they showed a release of cytochrome c into the cytosol, translocation of AIF and DFF40 (CAD) to the nuclei, and activation of caspase-7, caspase-3, PARP, and DFF45 (ICAD). In contrast, separate treatments of 5 μM of curcumin or 4 μg/ml of cisplatin, for 24 hours, did not induce apoptosis. Therefore, our data suggest that combination therapy with curcumin and cisplatin could be considered as a novel therapeutic strategy for human oral squamous cell carcinoma.