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Sample records for nephotettix cincticeps uhler

  1. Combined influence of Bt rice and rice dwarf virus on biological parameters of a non-target herbivore, Nephotettix cincticeps (Uhler (Hemiptera: Cicadellidae.

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    Qianjin Wang

    Full Text Available The advent of genetically modified (GM Bt rice creates the possibility of interactions among Bt crops, crop pathogens and non-target herbivores. In particular, information on how pathogen-infected Bt-expressing plants will influence non-target herbivores is necessary to predict the sustainability of GM cropping systems. Laboratory bioassays were conducted to evaluate the potential combined impacts of rice dwarf virus (RDV and two Bt rice lines, T1C-19 (Cry1C and T2A-1 (Cry2A, on non-target green rice leafhopper (GRLH, Nephotettix cincticeps (Uhler (Hemiptera: Cicadellidae. In the first experiment, GRLHs feeding preference tests on Bt rice lines compared to a parental control rice line, MH63, were conducted. As rice plants were uninfected with RDV, GRLHs generally preferred the control MH63 line over the two Bt lines during the initial 8 h, with no significant preference during the following 64 h. As rice plants were infected with RDV, there were no clear preferences between the Bt rice lines and the control MH63 line. In the second experiment, we assessed the combined influence of RDV-infection status and Bt rice lines on GRLH biological parameters. Egg duration, adult weights, and male adult longevity were significantly affected on RDV-infected Bt rice. Other parameters, egg hatching rate, nymph survival and fecundity were not significantly influenced. We infer that interaction effect among two testing Bt rice lines and RDV will not lead to enlarged pest populations, thus demonstrating that growing these two Bt rice lines will poses negligible risk to GRLH in sustainable rice agroecosystems. Long-term field experiments to monitor the population dynamics of GRLHs at large scale need to be carried out to confirm the current results.

  2. Combined influence of Bt rice and rice dwarf virus on biological parameters of a non-target herbivore, Nephotettix cincticeps (Uhler) (Hemiptera: Cicadellidae).

    Science.gov (United States)

    Wang, Qianjin; Han, Naishun; Dang, Cong; Lu, Zengbin; Wang, Fang; Yao, Hongwei; Peng, Yufa; Stanley, David; Ye, Gongyin

    2017-01-01

    The advent of genetically modified (GM) Bt rice creates the possibility of interactions among Bt crops, crop pathogens and non-target herbivores. In particular, information on how pathogen-infected Bt-expressing plants will influence non-target herbivores is necessary to predict the sustainability of GM cropping systems. Laboratory bioassays were conducted to evaluate the potential combined impacts of rice dwarf virus (RDV) and two Bt rice lines, T1C-19 (Cry1C) and T2A-1 (Cry2A), on non-target green rice leafhopper (GRLH), Nephotettix cincticeps (Uhler) (Hemiptera: Cicadellidae). In the first experiment, GRLHs feeding preference tests on Bt rice lines compared to a parental control rice line, MH63, were conducted. As rice plants were uninfected with RDV, GRLHs generally preferred the control MH63 line over the two Bt lines during the initial 8 h, with no significant preference during the following 64 h. As rice plants were infected with RDV, there were no clear preferences between the Bt rice lines and the control MH63 line. In the second experiment, we assessed the combined influence of RDV-infection status and Bt rice lines on GRLH biological parameters. Egg duration, adult weights, and male adult longevity were significantly affected on RDV-infected Bt rice. Other parameters, egg hatching rate, nymph survival and fecundity were not significantly influenced. We infer that interaction effect among two testing Bt rice lines and RDV will not lead to enlarged pest populations, thus demonstrating that growing these two Bt rice lines will poses negligible risk to GRLH in sustainable rice agroecosystems. Long-term field experiments to monitor the population dynamics of GRLHs at large scale need to be carried out to confirm the current results.

  3. Combined influence of Bt rice and rice dwarf virus on biological parameters of a non-target herbivore, Nephotettix cincticeps (Uhler) (Hemiptera: Cicadellidae)

    Science.gov (United States)

    The advent of genetically modified (GM) Bt rice creates the possibility of interactions among Bt crops, crop pathogens and non-target herbivores. In particular, information on how pathogen-infected Bt-expressing plants will influence non-target herbivores is necessary to predict the sustainability o...

  4. Does the aggressiveness of the prey modify the attack behavior of the predator Supputius cincticeps (Stål (Hemiptera, Pentatomidae? A agressividade da presa altera o comportamento de ataque do predador Supputius cincticeps (Stål (Hemiptera, Pentatomidae?

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    Rafael Braga da Silva

    2012-06-01

    Full Text Available Does the aggressiveness of the prey modify the attack behavior of the predator Supputius cincticeps (Stål (Hemiptera, Pentatomidae? The stink bug Supputius cincticeps (Stål (Hemiptera, Pentatomidae is a predator found in several Brazilian regions, which possesses desirable attributes as a natural control agent and in biological control programs. The aim of this study was to test if the attack behavior and predation success of S. cincticeps were affected by prey species. Larvae of Tenebrio molitor (L. (Coleoptera, Tenebrionidae, Spodoptera frugiperda (J. E. Smith (Lepidoptera, Noctuidae, and Thyrinteina arnobia (Stoll (Lepidoptera, Geometridae were offered to S. cincticeps in laboratory bioassays where predatory attack and prey defensive behaviors were observed for 2-hour periods. The attack behavior of S. cincticeps changed with the prey species offered. More than 25% of T. molitor and S. frugiperda larvae were immediately attacked, but T. arnobia was not immediately attacked by S. cincticeps. Successful attack (i.e., successful insertion of the predator stylets into the prey depends on the region of the body attacked, with a greater proportion of successful attacks in the anterior than in the median or posterior regions. Larvae of T. arnobia and S. frugiperda displayed a sequence of abrupt head and body movements in response to S. cincticeps attack. Attempts of predation were more successful on T. molitor and S. frugiperda than on T. arnobia. Information about the differential attack behavior of S. cincticeps on different prey species is important for designing successful biological control programs using this hemipteran predator.A agressividade da presa altera o comportamento de ataque do predador Supputius cincticeps (Stål (Hemiptera, Pentatomidae? O percevejo Supputius cincticeps (Stål (Hemiptera, Pentatomidae é um predador encontrado em várias regiões brasileiras, que possui atributos desejáveis como agente de controle natural ou em

  5. Development of Supputius cincticeps (Heteroptera, Pentatomidae) fed with Zophobas confusa, Tenebrio molitor (Coleoptera, Tenebrionidae) and Musca domestica (Diptera, Muscidae) larvae

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    Beserra, Eduardo B.; Zanuncio, Teresinha V.; Zanuncio, José C.; Santos, Germi P.

    1995-01-01

    Egg viability and nymphal development of the predatory bug Supputius cincticeps (Stål, 1860) were evaluated during two generations in the Biological Control Laboratory of the Núcleo de Biotecnologia Aplicada à Agropecuária (Bioagro/UFV) in Viçosa (Minas Gerais, Brazil) at 24.72±1.10ºC and photophase of 12 hours. Three treatments were represented by S. cincticeps fed with Zophobas confusa Gebien, 1906, Tenebrio molitor Linnaeus, 1758 and Musca domestica Linnaeus, 1758 larvae. Higher egg viabil...

  6. Does the aggressiveness of the prey modify the attack behavior of the predator Supputius cincticeps (Stål (Hemiptera, Pentatomidae?

    Directory of Open Access Journals (Sweden)

    Rafael Braga da Silva

    2012-06-01

    Full Text Available Does the aggressiveness of the prey modify the attack behavior of the predator Supputius cincticeps (Stål (Hemiptera, Pentatomidae? The stink bug Supputius cincticeps (Stål (Hemiptera, Pentatomidae is a predator found in several Brazilian regions, which possesses desirable attributes as a natural control agent and in biological control programs. The aim of this study was to test if the attack behavior and predation success of S. cincticeps were affected by prey species. Larvae of Tenebrio molitor (L. (Coleoptera, Tenebrionidae, Spodoptera frugiperda (J. E. Smith (Lepidoptera, Noctuidae, and Thyrinteina arnobia (Stoll (Lepidoptera, Geometridae were offered to S. cincticeps in laboratory bioassays where predatory attack and prey defensive behaviors were observed for 2-hour periods. The attack behavior of S. cincticeps changed with the prey species offered. More than 25% of T. molitor and S. frugiperda larvae were immediately attacked, but T. arnobia was not immediately attacked by S. cincticeps. Successful attack (i.e., successful insertion of the predator stylets into the prey depends on the region of the body attacked, with a greater proportion of successful attacks in the anterior than in the median or posterior regions. Larvae of T. arnobia and S. frugiperda displayed a sequence of abrupt head and body movements in response to S. cincticeps attack. Attempts of predation were more successful on T. molitor and S. frugiperda than on T. arnobia. Information about the differential attack behavior of S. cincticeps on different prey species is important for designing successful biological control programs using this hemipteran predator.

  7. Dynamical roguing model for controlling the spread of tungro virus via Nephotettix Virescens in a rice field

    Science.gov (United States)

    Blas, Nikki; David, Guido

    2017-10-01

    Rice tungro disease is described as a cancer due to its major impact on the livelihood of farmers and the difficulty of controlling it. Tungro is a semi-persistent virus transmitted by green leafhoppers called Nephotettix Virescens. In this paper, we presented a compartmental plant-vector model of the Nephotettix Virescens - rice plant interaction based on a system of ordinary differential equations to simulate the effects of roguing in controlling the spread of Tungro virus in a model rice field of susceptible rice variety (Taichung Native 1).

  8. Reproduction and longevity of Supputius cincticeps (Het.: Pentatomidae fed with larvae of Zophobas confusa, Tenebrio molitor (Col.: Tenebrionidae or Musca domestica (Dip.: Muscidae

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    José Cola Zanuncio

    2005-09-01

    Full Text Available Reproduction and longevity of Supputius cincticeps (Stål (Heteroptera: Pentatomidae fed on Zophobas confusa Gebien, Tenebrio molitor L. (Coleoptera: Tenebrionidae or Musca domestica (L. (Diptera: Muscidae larvae were studied during two generations at 24.7 ± 1.1ºC, 70 ± 10% R.H. and 12 h of photophase. Body weight of newly-emerged adults, oviposition period, number of egg masses, total number of eggs and longevity of S. cincticeps were higher when fed on Z. confusa or T. molitor larvae than on M. domestica larvae. Regardless of diet, S. cincticeps showed better reproduction and longevity in the second generation in laboratory conditions.Foram avaliadas, em duas gerações, a reprodução e a longevidade de Supputius cincticeps (Stål (Heteroptera: Pentatomidae alimentado com larvas de Zophobas confusa Gebien, Tenebrio molitor L. (Coleoptera: Tenebrionidae ou Musca domestica (L. (Diptera: Muscidae a 24,7 ± 1,1ºC, 70 ± 10% de U.R. e fotofase de 12 h. O peso de adultos recém emergidos, o período de oviposição, o número de posturas, de ovos totais e a longevidade de fêmeas de S. cincticeps foram maiores com larvas de Z. confusa ou T. molitor que com M. domestica. Independentemente do tipo de presa, S. cincticeps mostrou melhor performance reprodutiva e longevidade na segunda geração.

  9. Efeitos da temperatura e da defesa da presa no consumo pelo predador Supputius cincticeps (Stäl (Heteroptera:Pentatomidae Effects of temperature and of the prey defense on the consumption by the predator Supputius cincticeps (Stäl (Heteroptera:Pentatomidae

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    Francisco Roberto de Azevedo

    1999-02-01

    Full Text Available A pesquisa objetivou determinar se a temperatura e a defesa da presa afetam o consumo e a utilização de larvas de Tenebrio molitor L. por ninfas de Supputius cincticeps (Stäl. Quantificaram-se em cada um dos ínstares do predador Supputius cincticeps os consumos bruto e diário das larvas de T. molitor com e sem defesa, ganho de peso total e ganho de peso diário pelo predador. Foram determinados os efeitos da defesa da presa e da temperatura ambiente no consumo de alimento pelas ninfas de 2º, 3º, 4º e 5º ínstares de S. cincticeps. A pesquisa foi conduzida na Unidade de Controle Biológico da Embrapa-Centro Nacional de Pesquisa de Algodão, em Campina Grande, PB, a 20, 25, e 30ºC, 60±10% UR e fotofase de 14 horas. Os resultados mostraram que o consumo bruto de larvas de T. molitor pelo S. cincticeps depende do ínstar do predador e da temperatura, do ínstar do predador e da defesa da presa, e da temperatura e defesa da presa; o consumo diário de S. cincticeps depende do ínstar do predador e da temperatura, e do ínstar do predador e da defesa da presa, e o ganho de peso de S. cincticeps depende do seu ínstar, da temperatura e da defesa apresentada pelas larvas de T. molitor. O tamanho das larvas de T. molitor funciona como defesa ao ataque de S. cincticeps.The objective of the research was to determine if the temperature and pray defense affect the consumption and utilization of Tenebrio molitor L. larvae by nymphs of Supputius cincticeps (Stäl. The gross and daily consumptions of T. molitor larvae with and without defense by the predator Supputius cincticeps, and the gross and daily weight gains of the predator were quantified. Effects of the prey defense and temperature on the food consumption by the 2nd, 3rd, 4th and 5th instar nimphs of S. cincticeps were determined. The research was carried out in the Biological Control Unit of the Embrapa-Centro Nacional de Pesquisa de Algodão, at Campina Grande, PB, Brazil, at 20, 25, and

  10. Reproduction and longevity of Supputius cincticeps (Het.: Pentatomidae) fed with larvae of Zophobas confusa, Tenebrio molitor (Col.: Tenebrionidae) or Musca domestica (Dip.: Muscidae)

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    Zanuncio,José Cola; Beserra,Eduardo Barbosa; Molina-Rugama,Adrián José; Zanuncio,Teresinha Vinha; Pinon,Tobias Baruc Moreira; Maffia,Vanessa Pataro

    2005-01-01

    Reproduction and longevity of Supputius cincticeps (Stål) (Heteroptera: Pentatomidae) fed on Zophobas confusa Gebien, Tenebrio molitor L. (Coleoptera: Tenebrionidae) or Musca domestica (L.) (Diptera: Muscidae) larvae were studied during two generations at 24.7 ± 1.1ºC, 70 ± 10% R.H. and 12 h of photophase. Body weight of newly-emerged adults, oviposition period, number of egg masses, total number of eggs and longevity of S. cincticeps were higher when fed on Z. confusa or T. mol...

  11. Efeito de extratos de plantas do Cerrado em Dipetalogaster maxima (Uhler (Hemiptera, Reduviidae Effect of Cerrado plant extracts on Dipetalogaster maxima (Uhler (Hemiptera, Reduviidae

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    André A. M. Coelho

    2009-01-01

    Full Text Available A transmissão da doença de Chagas ocorre, principalmente, por meio de fezes de hemípteros hematófagos (Triatominae, os quais ingerem o Trypanosoma cruzi ao se alimentarem do sangue de pessoas ou outros mamíferos infectados. Para o controle dos triatomíneos, os piretróides são os principais inseticidas utilizados. Entretanto, algumas populações de insetos demonstraram resistência a determinados piretróides, indicando a necessidade do desenvolvimento de novos inseticidas eficazes no controle desses vetores. Assim, foi avaliada a atividade inseticida de 83 extratos vegetais, pertencentes a 35 espécies diferentes, em ninfas do primeiro estádio de Dipetalogaster maxima (Uhler, 1894 (Hemiptera: Reduviidae, triatomíneo encontrado no México. Para o teste tópico, foram aplicados 50 ìg de cada extrato nos tergitos abdominais de dez ninfas, em duplicata. Como controles, foram utilizados insetos tratados com etanol, acetona ou sem nenhum tipo de tratamento. Os triatomíneos foram observados durante 28 dias. Nenhum extrato apresentou atividade inseticida significativa, entretanto, o extrato hexânico do fruto e o etanólico da casca do caule de Simarouba versicolor (Simaroubaceae inibiram a taxa de ecdise em D. maxima (40% e 25%, respectivamente. Sugere-se que estes extratos sejam quimicamente investigados e monitorados por ensaios biológicos a fim de determinar os componentes, para que estes possam ser utilizados como modelos moleculares ou como compostos biorracionais nos programas de controle de insetos.Chagas disease, also known as American Trypanosomiasis, is chiefly transmitted by faeces of haematophagous bugs (Triatominae that ingested Trypanosoma cruzi from blood of infected people or other mammals. Pyrethroids have been the main insecticides used against these insects. However, some populations of insects have shown significant levels of resistance to several pyrethroids, indicating the need of new insecticides for the control of

  12. Multiple model mimicry and feeding behavior of the spider web-inhabiting damsel bug, Arachnocoris berytoides Uhler (Hemiptera: Nabidae), from Puerto Rico

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    Javier E. Mercado; Jorge A. Santiago-Blay

    2015-01-01

    The Neotropical genus, Arachnocoris Scott groups thirteen species of specialized spider web-inhabiting damsel bugs (Nabidae) distributed from Panama to Brazil and the West Indies. We present new information on the web behavior of A. berytoides Uhler from Puerto Rico. Three different life stages were observed on the spider webs, suggesting this species likely depends on...

  13. Morphology of the mouthparts of the spittlebug Philagra albinotata Uhler (Hemiptera: Cercopoidea: Aphrophoridae).

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    Wang, Tingting; Pan, Liuxing; Zhang, Yalin; Dai, Wu

    2015-03-01

    Mouthparts associated with feeding behavior and feeding habits are important sensory and feeding structures in insects. To obtain a better understanding of feeding in Cercopoidea, the morphology of mouthparts of the spittlebug, Philagra albinotata Uhler was examined using scanning electron microscopy. The mouthparts of P. albinotata are of the typical piercing-sucking type found in Hemiptera, comprising a cone-shaped labrum, a tube-like, three-segmented labium with a deep groove on the anterior side, and a stylet fascicle consisting of two mandibular and two maxillary stylets. The mandibles consist of a dorsal smooth region and a ventral serrate region near the apical half of the external convex region, and bear five nodules or teeth on the dorsal external convex region on the distal extremity; these are regarded as unique features that distinguish spittlebugs from other groups of Hemiptera. The externally smooth maxillary stylets, interlocked to form a larger food canal and a smaller salivary canal, are asymmetrical only in the internal position of longitudinal carinae and grooves. One dendritic canal is found in each maxilla and one in each mandible. Two types of sensilla trichodea, three types of sensilla basiconica and groups of multi-peg structures occur in different locations on the labium, specifically the labial tip with two lateral lobes divided into anterior sensory fields with ten small peg sensilla arranged in a 5+4+1 pattern and one big peg sensillum, and posterior sensory fields with four sensilla trichodea. Compared with those of previously studied Auchenorrhyncha, the mouthparts of P. albinotata may be distinguished by the shape of the mandibles, the multi-peg structures and a tooth between the salivary canal and the food canal on the extreme end of the stylets. The mouthpart morphology is illustrated using scanning electron micrographs, and the taxonomic and putative functional significance of the different structures is briefly discussed

  14. Potencial reprodutivo de Supputius cincticeps (Stal (Heteroptera: Pentatomidae influenciado pelo peso do corpo da fêmea - DOI: 10.4025/actascibiolsci.v25i1.2081 Reproductive potential of the predator Supputius cincticeps (Heteroptera: Pentatomidae affected by female body weight - DOI: 10.4025/actascibiolsci.v25i1.2081

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    Jose Eduardo Serrão

    2003-04-01

    Full Text Available O potencial reprodutivo de fêmeas de Supputius cincticeps (Stal (Heteroptera: Pentatomidae de duas classes de peso foi avaliado. Machos e fêmeas desse predador foram obtidos de ninfas alimentadas com pupas de Tenebrio molitor L. (Coleoptera: Tenebrionidae. Foram analisadas fêmeas com peso inferior a 45 mg (fêmeas leves e superior a 60 mg (fêmeas pesadas. A longevidade e os períodos de pré-oviposição, oviposição e pós-oviposição foram semelhantes entre fêmeas das duas classes de peso, enquanto aquelas mais pesadas apresentaram maior número de posturas, ovos, ovos/postura e ninfas. Períodos entre posturas e de incubação dos ovos foram menores para fêmeas com peso superior a 60mg. Esses resultados são discutidos em relação ao uso de fêmeas mais pesadas de S. cincticeps para aumentar a produção em criação massal desse predadorThe reproductive potential of Supputius cincticeps (Stal (Heteroptera: Pentatomidae females of two weight classes was evaluated with males and females of this predator obtained from nymphs fed on Tenebrio molitor L. (Coleoptera: Tenebrionidae pupae. Females of S. cincticeps weighing less than 45 mg (light females and more than 60 mg (heavy females constituted the treatments. Pre-oviposition, oviposition and post-oviposition periods besides adult longevity were similar between treatments while number of egg masses, eggs, eggs/egg mass and number of nymphs hatched were higher for heavier females. Periods between egg mass laying and egg incubation were shorter for insects of the last treatment. These results are discussed in relation to the use of heavier females of S. cincticeps to improve mass rearing of this predator in laboratory

  15. PENGARUH DOSIS SUBLETAL EKSTRAK SAMBILATA (ANDROGRAPHIS PANICULATA NEES TERHADAP AKTIVITAS MUSUH ALAMI DAN KEPERIDIAN WERENG HIJAU, NEPHOTETTIX VIRESCENS DISTANT

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    I Nyoman Widiarta dan Dede Kusdiaman .

    2011-11-01

    Full Text Available Effect of sublethal doses of sambilata extract to the fecundity and natural enemies activity of the green leafhopper, Nepothettix virescens Distant. Sambilata (Andrographis paniculata is a tropical herb which has antifeeding property and could reduce rice tungro virus transmission by the rice green leafhopper (GLH, Nephotettix virescens.  Series of test were conducted to clarify the effect of sublethal doses of sambilata to the fecundity and natural enemies activity of the GLH. The objective of the test was to know wether sublethal dose of sambilata could cause physiological or ecological resurgence. The results of test showed that foliar spraying of sambilata extract at concentration of 100 and 1000 ppm to rice seedlings reduced the GLH females’s fecundity. Spraying sambilata extract up to dose of 100 ppm on rice seedlings and GLH did not reduce Lycosa preying activity. Egg parasitoid activity was not affected by sambilata application on rice seedlings bore GLH eggs. Thus  the probability of sublethal dose of sambilata to cause physiological or ecological resurgence was low.

  16. Desenvolvimento de Supputius cincticeps (Heteroptera, Pentatomidae alimentado com larvas de Zophobas confusa, Tenebrio molitor (Coleoptera, Tenebrionidae e Musca domestica (Diptera, Muscidae Development of Supputius cincticeps (Heteroptera, Pentatomidae fed with Zophobas confusa, Tenebrio molitor (Coleoptera, Tenebrionidae and Musca domestica (Diptera, Muscidae larvae

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    Eduardo B. Beserra

    1995-09-01

    Full Text Available Egg viability and nymphal development of the predatory bug Supputius cincticeps (Stål, 1860 were evaluated during two generations in the Biological Control Laboratory of the Núcleo de Biotecnologia Aplicada à Agropecuária (Bioagro/UFV in Viçosa (Minas Gerais, Brazil at 24.72±1.10ºC and photophase of 12 hours. Three treatments were represented by S. cincticeps fed with Zophobas confusa Gebien, 1906, Tenebrio molitor Linnaeus, 1758 and Musca domestica Linnaeus, 1758 larvae. Higher egg viability of this predator was found when the preys were Z. confusa and T. molitor, 74.46% and 80.91 %, than in M. domestica, 57.02%, but incubation period showed no differences between preys. Shorter nymphal development and higher nymphal viability were found with Z. confusa and T. molitor than with M. domestica. Higher weight increase was found for nymphs which originated males and females in the second generation specialy with the first two preys.

  17. Dampak Andrografolid dan Dua Jenis Insektisida Sintetik sebagai Penghambat Makan Nephotettix virescens, terhadap Transmisi Virus Tungro

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    I Nyoman Widiarta

    1998-07-01

    Full Text Available The effect of andrographolide and two synthetic insecticides of pymetrozine and imidacloprid, an antifeedant against N. virescens (Distant, to the rice virus transmission were tested using test tube inoculation method in the green house under natural photoperiod and average temperature of 28.5oC. The root of tungro diseased plant were soaked for 24 hours into tested materials before acquisition feeding to test virus acquisition inhibition, while root of rice seedlings were soaked into tested material for 24 hours before inoculation feeding to test virus inoculation inhibition. The results of studies showed that andrographolide, pymetrozine, and imidacloprid significantly reduced virus acquisition and virus inoculation by N. virescens. Pymetrozine and andrographolide treatments to the tungro diseased plants at concentration of 20 ppm significantly reduced proportion of viruliferous vector to become 17% in average. The increasing concentration into 40 ppm of both materials did not significantly reduce proportion of viruliferous vector. Imidacloprid at concentration of 0.01 and 0.02 ppm, completey inhibited feeding acquisition. Pymetrozine and andrographolide treatment at concentration of 20 ppm to the rice seedlings reduced significantly virus transmission by N. virescens to become 69% in average. The increasing concentration of pymetrozine up to 40 ppm did not reduce virus transmission rate. Imidacloprid at concentration of 0.01 ppm and 0.02 ppm reduced virus transmission to become 25% and 39%, respectively. It was concluded that imidacloprid was the most effective antifeedant reducing virus transmission by N. virescens among tested chemicals. Key words: antifeedant, N. virescens, rice tungro virus disease

  18. Lethal concentration of carbofuran to brown planthopper (Nilaparvata lugens) and green leaf-hopper (Nephotettix virecence)

    International Nuclear Information System (INIS)

    Kuswadi, A.N.; Sumatra, M.; Anwar, E.; Soekarna, D.

    1988-01-01

    An oral toxicity test of carbofuran to brown planthopper and green leaf-hopper using sucrose solution as feed given to the hopper through a membrane feeding system was conducted in the laboratory, pure carbofuran was dilute in the feeding solution. The 50 percent lethal concentration (LC-50) of this insecticide to adult and nymph of brown planthopper were 0.21 and 0.43 ppm, respectively, while those to adult and nymph of green leaf-hopper were 0.43 and 0.58 ppm. The LC 90 were 0.56 an 0.90 ppm to adult and nymph of brown planthopper, and 1.20 and 1.60 ppm to adult and nymph of green leaf-hopper, respectively. The brown planthopper was found to be more susceptible than the nymph. When carbofuran was applied to rice plant, this insecticide was accumulated more in the leaf than in the stem, so that green leaf-hopper got more toxicity than the brown planthopper. (authors). 5 refs, 7 figs

  19. Karakter Populasi Wereng Hijau, Nephotettix virescens (Hemiptera: Cicadellidae di Wilayah Endemi dan Non Endemi Penyakit Tungro Padi

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    Supriyadi Supriyadi

    2004-12-01

    Full Text Available The objectives of this research were to determine the species composition, distribution pattern and virus transmission properties of N. virescens. Sweep net sampling of the leafhopper and others tungro vectors population were conducted from endemic areas in Central Java, East Java and Bali and also non endemic areas from Central Java and East Java. The species composition and distribution pattern of the leafhopper were studied in seedbeds and early stage of rice crop (30 days after transplanting. Inoculation test using Cisadane seedlings was conducted to determine the efficiency of virus transmission by N. virescens colonies. Four tungro virus vectors were found in all areas, namely N. virescens, N. nigropictus, N. malayanus, and Recilia sp. The domination of N. virescens occurred either in the endemic area or the non endemic areas. However, the domination of N. virescens did not correlate with the occurrence of the disease in the endemic area. The distribution pattern of N. virescens was regular. The number of N. virescens active transmitter in the endemic area was higher than that in the non-endemic areas. In addition, the female of N. virescens was more efficient in transmitting the tungro virus than that of the male.

  20. Pertumbuhan Populasi dan Oviposisi Wereng Hijau, Nephotettix virescens Distant (Hemiptera: Cicadellidae Berkaitan dengan saat Padi Keluar Malai

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    I Nyoman Widiarta

    1996-12-01

    more eggs on early maturing variety after flowering stage than that on late maturing variety before flowering stage (p< 0.01; t-test in the pot experiment. Those field and pot experiment facts indicated that the first generation of adult emigrant influenced the population fluctuation in the fields, because the density of predator, Lycosa, was lower in the early maturing variety than in the late maturing variety in the wet season crop of 1994/1995 and it was similar in the dry season crop of 1995.

  1. Uptake of 14C-carbofuran from rice plants by brown planthopper (nilaparvata lugens stal) and green leafhopper (Nephotettix virencence)

    International Nuclear Information System (INIS)

    Sumatra, M.; Anwar, E.; Kuswadi, A.N.; Soekarna, D.

    1988-01-01

    An experiment was carried out to determine the amount of 14-C-carbofuran taken up by brown planthopper (BPH) and green leafhopper (GLH) from ride plants containing 14-C-carbofuran. The roots of 30 days old rice plants were immersed in Kimura B solution containing carbofuran (0.6ug/ml) with activity of 18600 pCi/ml. After 3 days, 20 BPH and 20 GLH released onto the rice stems and leaves. The mortalities of BPH and GLH were similar after 24 and 48 hours of the release. The average radioactivity found in living GLH was 3.5 times of those found in living GLH was 3.5 times of those found in living BPH. And in dead GLH was 3.2 times on those in dead BPH. Radioactivity in rice leaves was 3.5 times of those in stems. This layer chromatograph of extracts of Kimura B solution, stems, and leaves showed that small amounts of carbofuran had degraded to substances like 3-OH-carbofuran and 3-keto-carbofuran. The percentage of radioactivity found as carbofuran decreased with time, while the amount of 3-ket-carbofuran increased. (authors). 6 refs, 2 figs, 6 tab

  2. Molecular cloning and characterization of an acetylcholinesterase cDNA in the brown planthopper, Nilaparvata lugens.

    Science.gov (United States)

    Yang, Zhifan; Chen, Jun; Chen, Yongqin; Jiang, Sijing

    2010-01-01

    A full cDNA encoding an acetylcholinesterase (AChE, EC 3.1.1.7) was cloned and characterized from the brown planthopper, Nilaparvata lugens Stål (Hemiptera: Delphacidae). The complete cDNA (2467 bp) contains a 1938-bp open reading frame encoding 646 amino acid residues. The amino acid sequence of the AChE deduced from the cDNA consists of 30 residues for a putative signal peptide and 616 residues for the mature protein with a predicted molecular weight of 69,418. The three residues (Ser242, Glu371, and His485) that putatively form the catalytic triad and the six Cys that form intra-subunit disulfide bonds are completely conserved, and 10 out of the 14 aromatic residues lining the active site gorge of the AChE are also conserved. Northern blot analysis of poly(A)+ RNA showed an approximately 2.6-kb transcript, and Southern blot analysis revealed there likely was just a single copy of this gene in N. lugens. The deduced protein sequence is most similar to AChE of Nephotettix cincticeps with 83% amino acid identity. Phylogenetic analysis constructed with 45 AChEs from 30 species showed that the deduced N. lugens AChE formed a cluster with the other 8 insect AChE2s. Additionally, the hypervariable region and amino acids specific to insect AChE2 also existed in the AChE of N. lugens. The results revealed that the AChE cDNA cloned in this work belongs to insect AChE2 subgroup, which is orthologous to Drosophila AChE. Comparison of the AChEs between the susceptible and resistant strains revealed a point mutation, Gly185Ser, is likely responsible for the insensitivity of the AChE to methamidopho in the resistant strain.

  3. Feeding and defecation behavior of Triatoma rubida (Uhler, 1894) (Hemiptera: Reduviidae) under laboratory conditions, and its potential role as a vector of Chagas disease in Arizona, USA.

    Science.gov (United States)

    Reisenman, Carolina E; Gregory, Teresa; Guerenstein, Pablo G; Hildebrand, John G

    2011-10-01

    Chagas disease is caused by the parasite Trypanosoma cruzi, which is transmitted to humans by blood-sucking triatomine insects. This disease is endemic throughout Mexico and Central and South America, but only a few autochthonous cases have been reported in the United States, despite the fact that infected insects readily invade houses and feed on humans. Competent vectors defecate during or shortly after feeding so that infective feces contact the host. We thus studied the feeding and defecation behaviors of the prevalent species in southern Arizona, Triatoma rubida. We found that whereas defecation during feeding was frequent in females (93%), it was very rare in immature stages (3%), and absent in males. Furthermore, more than half of the immature insects that exhibited multiple feeding bouts (62%) defecated during interruptions of feeding, i.e., while likely on or near the host. These results indicate that T. rubida potentially could transmit T. cruzi to humans.

  4. Estudos bionômicos de Dipetalogaster maximus (Uhler, 1894 (Hemiptera - Triatominae: II - Influência da dieta sobre o ciclo biológico e resistência ao jejum Bionomic studies of Dipetalogaster maximus (Uhler, 1894 (Hemiptera: Triatominae: II. Influence of diet on the biological cycle and resitance to fast

    Directory of Open Access Journals (Sweden)

    Jane Margaret Costa

    1987-03-01

    Full Text Available Avaliou-se a influência de dois tipos de dieta na cronologia da ontogênsese de Dipetalogaster maximus. Alimentou-se um grupo em sangue de camundongos normais (C e outro em sangue de pombos (P. Ambos foram mantidos em estufa B.O.D. a 28ºC e 65% U.R. O grupo alimentado em C, atingiu a fase adulta com X=130,1 dias e o grupo alimentado em P com X=145,68 dias. A percentagem total de mortalidade foi significativamente superior nos alimentados em P (63,71% em relação aos alimentados em C (31,18%. Quanto á resistência ao jejum, o período de sobrevivência foi acentuadamente maior para o grupo alimentado em C. Principalmente nos 3º, 4º e 5º estádios. Estas observações complementam nossos registros anteriores desta espécie, mantida nas mesmas condições, sobre: fertilidade das fêmeas, ritmo de postura, viabilidade dos ovos e curva da mortalidade x fertilidade.Two kinds of blood-meal were assayed in order to broaden the knowledge of the biology of Dipetalogaster maximus: one group of insects was fed on normal mouse blood (C and another group fed on pigeon blood (P. Both groups were kept in a B.O.D. - chamber (28ºC and 65% R.H.. Significant data concerning their development was registered: the group fed on C reached the adult stage in X = 130,1 days and the group fed on P in X = 145,6 days. Mortality of group fed on P, (63,71% was doubled that of group fed on C (31,18%. The period of survival, as measured by resistance to starvation, was markedly greater in group fed on C, particularly in the third, fourth and fifth stages. These observations complete our former records of this species, kept under the same conditions of female fertility, egg vialbility and comparative mortality and fertility rates.

  5. Sources of hydrocarbons in sediments of the Mandovi estuary and the Marmugoa harbour, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Harji, R.R.; Yvenat, A.; Bhosle, N.B.

    anthropogenic hydrocarbon inputs. Mar Environ Res 1992;33:223-253. Stout SA, Uhler AD, McCarthy KJ, Emsbo-Mattingly S. Chemical fingerprinting of hydrocarbons. In: Murphy BL, Morrison R (Eds.), Introduction to Environmental Forensics. Academic Press, Boston...

  6. Review of the West Indian Arachnocoris Scott, 1881 (Hemiptera: Nabidae), with descriptions of two new species, and a catalog of the species

    Science.gov (United States)

    Javier E. Mercado; Jorge A. Santiago-Blay; Michael D. Webb

    2016-01-01

    We review the West Indian species of Arachnocoris, a genus of spider-web dwelling kleptoparasitic nabids. We recognize five species: A. berytoides Uhler from Grenada, A. darlingtoni n. sp. from Hispaniola, A. karukerae Lopez-Moncet from Guadeloupe, A. portoricensis n. sp. from Puerto Rico, and A. trinitatis Bergroth from Trinidad. West Indian Arachnocoris...

  7. Diet-dependent fecundity of the spiders Atypena formosana and Pardosa pseudoannulata, predators in irrigated rice

    DEFF Research Database (Denmark)

    Sigsgaard, L.; Toft, S.; Villareal, S.

    2001-01-01

    The fecundity of the spiders Atypena formosana and Pardosa pseudoannulata was assessed on diets of brown planthopper Nilaparvata lugens (BPH), green leafhopper Nephotettix virescens (GLH), Collembola (Entomobryidae), Drosophila melanogaster and three prey mixtures; BPH-GLH, BPH-GLH-Collembola and......The fecundity of the spiders Atypena formosana and Pardosa pseudoannulata was assessed on diets of brown planthopper Nilaparvata lugens (BPH), green leafhopper Nephotettix virescens (GLH), Collembola (Entomobryidae), Drosophila melanogaster and three prey mixtures; BPH-GLH, BPH......-GLH-Collembola and a full mixed diet of BPH-GLH-Collembola-D. melanogaster. Egg production and hatching success was high in A. formosana except on the BPH, the GLH and the BPH-GLH diets. In P. pseudoannulata egg production and hatching success was lowest on diets of GLH and BPH-GLH, whereas this spider used BPH better....... Differences between offspring sizes were small. Survival of A. formosana females was lowest on the GLH and BPH-GLH diets. In P. pseudoannulata survival did not differ significantly. Food conversion efficiency was highest on the Collembola and the D. melanogaster diets for both spiders. Overall, diets...

  8. Scalable privacy-preserving data sharing methodology for genome-wide association studies: an application to iDASH healthcare privacy protection challenge.

    Science.gov (United States)

    Yu, Fei; Ji, Zhanglong

    2014-01-01

    In response to the growing interest in genome-wide association study (GWAS) data privacy, the Integrating Data for Analysis, Anonymization and SHaring (iDASH) center organized the iDASH Healthcare Privacy Protection Challenge, with the aim of investigating the effectiveness of applying privacy-preserving methodologies to human genetic data. This paper is based on a submission to the iDASH Healthcare Privacy Protection Challenge. We apply privacy-preserving methods that are adapted from Uhler et al. 2013 and Yu et al. 2014 to the challenge's data and analyze the data utility after the data are perturbed by the privacy-preserving methods. Major contributions of this paper include new interpretation of the χ2 statistic in a GWAS setting and new results about the Hamming distance score, a key component for one of the privacy-preserving methods.

  9. Scalable privacy-preserving data sharing methodology for genome-wide association studies.

    Science.gov (United States)

    Yu, Fei; Fienberg, Stephen E; Slavković, Aleksandra B; Uhler, Caroline

    2014-08-01

    The protection of privacy of individual-level information in genome-wide association study (GWAS) databases has been a major concern of researchers following the publication of "an attack" on GWAS data by Homer et al. (2008). Traditional statistical methods for confidentiality and privacy protection of statistical databases do not scale well to deal with GWAS data, especially in terms of guarantees regarding protection from linkage to external information. The more recent concept of differential privacy, introduced by the cryptographic community, is an approach that provides a rigorous definition of privacy with meaningful privacy guarantees in the presence of arbitrary external information, although the guarantees may come at a serious price in terms of data utility. Building on such notions, Uhler et al. (2013) proposed new methods to release aggregate GWAS data without compromising an individual's privacy. We extend the methods developed in Uhler et al. (2013) for releasing differentially-private χ(2)-statistics by allowing for arbitrary number of cases and controls, and for releasing differentially-private allelic test statistics. We also provide a new interpretation by assuming the controls' data are known, which is a realistic assumption because some GWAS use publicly available data as controls. We assess the performance of the proposed methods through a risk-utility analysis on a real data set consisting of DNA samples collected by the Wellcome Trust Case Control Consortium and compare the methods with the differentially-private release mechanism proposed by Johnson and Shmatikov (2013). Copyright © 2014 Elsevier Inc. All rights reserved.

  10. METARHIZIUM ANISOPLIAE DAN ANDROGRAPHIS PANICULATA TERHADAP SERANGGA BUKAN HAMA SASARAN

    Directory of Open Access Journals (Sweden)

    Dini Yuliani

    2016-04-01

    Full Text Available The objective of this study was to determine the effect of Metarhizium anisopliae and Andrographis paniculata to the natural enemies of Nephotettix virescens and non-target insect pests. This research was conducted in tungro endemic areas in Subang District, West Java in the wet season 2013/2014. The method of research used a split plot design with four replications. The main plot was IR66, Inpari 9, and Ciherang varieties. Subplot was the application of M. anisopliae, A. paniculata, and control. Observations were carried out five times started at nursery (2 weeks after seedling, 14, 28, 42, and 56 days after planting using insect nets, double swing 10 times on each plot observations. The results show M. anisopliae and A. paniculata not adversely affect on non-target insect pests such as Chironomid and natural enemies of N. virescens namely Lycosa pseudoannulata, Cyrtorhinus lividipennis, Sepedon sp., damselfly, Tipulidae sp., Telenomus sp., dragonfly, and Tetrastichus sp.. Efficacy of M. anisopliae and A. paniculata as one of the control strategies that are environmentally friendly and proved not harmful to non-target insect pests.

  11. Selectable antibiotic resistance marker gene-free transgenic rice harbouring the garlic leaf lectin gene exhibits resistance to sap-sucking planthoppers.

    Science.gov (United States)

    Sengupta, Subhadipa; Chakraborti, Dipankar; Mondal, Hossain A; Das, Sampa

    2010-03-01

    Rice, the major food crop of world is severely affected by homopteran sucking pests. We introduced coding sequence of Allium sativum leaf agglutinin, ASAL, in rice cultivar IR64 to develop sustainable resistance against sap-sucking planthoppers as well as eliminated the selectable antibiotic-resistant marker gene hygromycin phosphotransferase (hpt) exploiting cre/lox site-specific recombination system. An expression vector was constructed containing the coding sequence of ASAL, a potent controlling agent against green leafhoppers (GLH, Nephotettix virescens) and brown planthopper (BPH, Nilaparvata lugens). The selectable marker (hpt) gene cassette was cloned within two lox sites of the same vector. Alongside, another vector was developed with chimeric cre recombinase gene cassette. Reciprocal crosses were performed between three single-copy T(0) plants with ASAL- lox-hpt-lox T-DNA and three single-copy T(0) plants with cre-bar T-DNA. Marker gene excisions were detected in T(1) hybrids through hygromycin sensitivity assay. Molecular analysis of T(1) plants exhibited 27.4% recombination efficiency. T(2) progenies of L03C04(1) hybrid parent showed 25% cre negative ASAL-expressing plants. Northern blot, western blot and ELISA showed significant level of ASAL expression in five marker-free T(2) progeny plants. In planta bioassay of GLH and BPH performed on these T(2) progenies exhibited radical reduction in survivability and fecundity compared with the untransformed control plants.

  12. Perbandingan Efek Pemberian Bioinsektisida dan Ekstrak Kompos terhadap Produksi Padi Ratun dan Populasi Serangga Hama

    Directory of Open Access Journals (Sweden)

    Siti Herlinda

    2015-06-01

    Full Text Available The advantages of ratooning rice are to save water, cost production, labor, preparation time for planting and harvesting, but the ratooning productivity is still low.  This research aimed to study the effect of the bioinsecticide and compost extract on ratooning rice production and insect populations. The ratooning rice was applied by bioinsecticide, compost extract, and combination of bioinsecticide and compost extract with dose 2 L ha-1  per application, respectively. Data of agronomic variables were statistically analyzed using analysis of variance, whereas insect pest population data were analyzed using Chi Square test. The seedling height of ratoon applied by compost extract was the highest among treatments. The number of productive tillers per clumps and rice production on plot applied by compost extract were higher than the insecticide treatment. At the age of 17 day-ratooning rice, application bioinsecticide reduced the population of insect pests, such as Ciccadulina bipunctata, Recilia dorsalis, Nilaparvata lugens, and Nephotettix nigropictus. Thus, application of compost extract tended to improved the growth and production of the ratooning rice, while the bioinsecticide decreased the insect pest population.Keywords: Beauveria bassiana, rice growth, production

  13. Geographic and Research Center Origins of Rice Resistance to Asian Planthoppers and Leafhoppers: Implications for Rice Breeding and Gene Deployment

    Directory of Open Access Journals (Sweden)

    Finbarr G. Horgan

    2017-09-01

    Full Text Available This study examines aspects of virulence to resistant rice varieties among planthoppers and leafhoppers. Using a series of resistant varieties, brown planthopper, Nilaparvata lugens, virulence was assessed in seedlings and early-tillering plants at seven research centers in South and East Asia. Virulence of the whitebacked planthopper, Sogatella furcifera, in Taiwan and the Philippines was also assessed. Phylogenetic analysis of the varieties using single-nucleotide polymorphisms (SNPs indicated a clade of highly resistant varieties from South Asia with two further South Asian clades of moderate resistance. Greenhouse bioassays indicated that planthoppers can develop virulence against multiple resistance genes including genes introgressed from wild rice species. Nilaparvata lugens populations from Punjab (India and the Mekong Delta (Vietnam were highly virulent to a range of key resistance donors irrespective of variety origin. Sogatella furcifera populations were less virulent to donors than N. lugens; however, several genes for resistance to S. furcifera are now ineffective in East Asia. A clade of International Rice Research Institute (IRRI-bred varieties and breeding lines, without identified leafhopper-resistance genes, were highly resistant to the green leafhopper, Nephotettix virescens. Routine phenotyping during breeding programs likely maintains high levels of quantitative resistance to leafhoppers. We discuss these results in the light of breeding and deploying resistant rice in Asia.

  14. Alarm Pheromone Activity of Nymph-specific Geraniol in Chrysanthemum Lace Bug Corythucha marmorata against Adults and Nymphs.

    Science.gov (United States)

    Watanabe, Kisaki; Shimizu, Nobuhiro

    2015-09-01

    The exotic insect pest Corythucha marmorata (Uhler) is increasingly spreading in Japan using the weed Solidago canadensis L. as a major host plant. The nymphs form colonies on the backs of leaves where they crowd together; however, aggregation does not occur in the adults. When an individual nymph is crushed using a needle tip and further the needle tip covered with the nymph's bodily fluids is moved slowly toward the center of the crowd, the surrounding nymphs display an escape behavior and their aggregation is disrupted. We detected geraniol as a nymph-specific volatile component. Bioassay results indicated that geraniol was effective as an alarm pheromone on second to fifth instar nymphs. Furthermore, we found that male and female adults responded sensitively to the alarm pheromone produced by nymphs. These results suggest that although the adult insects do not secrete geraniol, they can detect it produced by nymphs, thereby retaining the ability to escape from danger while suppressing the cost of geraniol production. The present study is the first to demonstrate that an alarm pheromone secreted by nymphs is also effective in adults among Tingidae.

  15. Patogenisitas Virus Tungro pada Varietas Tetua Padi Tahan Tungro

    Directory of Open Access Journals (Sweden)

    R Heru Praptana

    2014-08-01

    Full Text Available Tungro is one of the major diseases in rice which has become a constraint in increasing rice production in Indonesia. Tungro is caused by infection of two different viruses, i.e. Rice tungro bacilliform virus (RTBV and Rice tungro spherical virus (RTSV, both of which can only be transmitted by green leafhoppers Nephotettix virescens (Distant in a semipersistent manner. Since there is an indication of the existance of virulence variation of tungro viruses from different areas and the specific relationship between resistance of varieties and tungro viruses isolates, it is important to study the pathogenicity of tungro viruses from some endemic areas in Indonesia. This study aimed to identify the pathogenicity of tungro viruses from several endemic areas in Indonesia in some resistant varieties. One susceptible variety i.e. TN1 and ten resistant varieties were used in the study. Surveys and collection of infected plants and green leafhoppers were done in tungro endemic areas, namely West Java, Central Java, Yogyakarta, Central Sulawesi, West Sulawesi, South Sulawesi, Bali and West Nusa Tenggara. Artificial transmission using the test tube method was used in the pathogenicity test. Green leafhoppers caught from the field were used as transmitters.. The pathogenicity of tungro viruses were identified by the values of the incidence of tungro and the diseases indexes (DI. The result showed that difference in pathogenicity of tungro viruses in some resistant varieties was observed. Isolates from Central Java, Central Sulawesi and West Nusa Tenggara were able to infect all of resistant varieties and the pathogenicity of Central Java isolate was the highest among the other isolates.

  16. Wolbachia infection complexity among insects in the tropical rice-field community.

    Science.gov (United States)

    Kittayapong, P; Jamnongluk, W; Thipaksorn, A; Milne, J R; Sindhusake, C

    2003-04-01

    Wolbachia are a group of intracellular bacteria that cause reproductive alterations in their arthropod hosts. Widely discordant host and Wolbachia phylogenies indicate that horizontal transmission of these bacteria among species sometimes occurs. A likely means of horizontal transfer is through the feeding relations of organisms within communities. Feeding interactions among insects within the rice-field insect community have been well documented in the past. Here, we present the results of a polymerase chain reaction-based survey and phylogenetic analysis of Wolbachia strains in the rice-field insect community of Thailand. Our field survey indicated that 49 of 209 (23.4%) rice-field insect species were infected with Wolbachia. Of the 49 infected species, 27 were members of two feeding complexes: (i) a group of 13 hoppers preyed on by 2 mirid species and parasitized by a fly species, and (ii) 2 lepidopteran pests parasitized by 9 wasp species. Wolbachia strains found in three hoppers, Recilia dorsalis, Nephotettix malayanus and Nisia nervosa, the two mirid predators, Cyrtorhinus lividipennis and Tytthus chinensis, and the fly parasitoid, Tomosvaryella subvirescens, were all in the same Wolbachia clade. In the second complex, the two lepidopteran pests, Cnaphalocrocis medinalis and Scirpophaga incertulas, were both infected with Wolbachia from the same clade, as was the parasitoid Tropobracon schoenobii. However, none of the other infected parasitoid species in this feeding complex was infected by Wolbachia from this clade. Mean (+/- SD) genetic distance of Wolbachia wsp sequences among interacting species pairs of the hopper feeding complex (0.118 +/- 0.091 nucleotide sequence differences), but not for the other two complexes, was significantly smaller than that between noninteracting species pairs (0.162 +/- 0.079 nucleotide sequence differences). Our results suggest that some feeding complexes, such as the hopper complex described here, could be an important

  17. Significance of the tropical fire ant Solenopsis geminata (hymenoptera: formicidae) as part of the natural enemy complex responsible for successful biological control of many tropical irrigated rice pests.

    Science.gov (United States)

    Way, M J; Heong, K L

    2009-10-01

    The tropical fire ant Solenopsis geminata (Fabricius) often nests very abundantly in the earthen banks (bunds) around irrigated rice fields in the tropics. Where some farmers habitually drain fields to the mud for about 3-4 days, the ants can quickly spread up to about 20 m into the fields where they collect food, including pest prey such as the eggs and young of the apple snail Pomacea caniculata (Lamarck) and insects such as lepidopterous larvae and hoppers, notably Nilaparvata lugens (Stäl) the brown planthopper (Bph) and green leafhoppers Nephotettix spp. Even in drained fields, the activity of S. geminata is restricted by rainfall in the wet season. The relatively few ant workers that forage characteristically into drained fields and on to the transplanted clumps of rice plants (hills) kill the normally few immigrant Bph adults but are initially slower acting than other species of the natural enemy complex. However, larger populations of Bph are fiercely attacked and effectively controlled by rapidly recruited ant workers; whereas, in the absence of the ant, the other natural enemies are inadequate. In normal circumstances, there is no ant recruitment in response to initially small populations of immigrant Bph and no evidence of incompatibility between ant foragers and other natural enemies such as spiders. However, when many ants are quickly and aggressively recruited to attack large populations of Bph, they temporarily displace some spiders from infested hills. It is concluded that, in suitable weather conditions and even when insecticides kill natural enemies within the rice field, periodic drainage that enables S. geminata to join the predator complex is valuable for ant-based control of pests such as snails and Lepidoptera, and especially against relatively large populations of Bph. Drainage practices to benefit ants are fully compatible with recent research, which shows that periodic drainage combats problems of 'yield decline' in intensively irrigated

  18. Laboratory bioassays to estimate the lethal and sublethal effects of various insecticides and fungicides on Deraeocoris brevis (Hemiptera: Miridae).

    Science.gov (United States)

    Amarasekare, K G; Shearer, P W

    2013-04-01

    This laboratory bioassay focused on lethal and sublethal effects of five insecticides (chlorantraniliprole, cyantraniliprole, spinetoram, novaluron, and lambda-cyhalothrin) and two fungicide treatments (sulfur and a mixture of copper hydroxide and mancozeb) on the predatory mired bug, Deraeocoris brevis (Uhler) (Hemiptera: Miridae) using second instars and adult males and females. Formulated pesticides were tested using concentrations that were equivalent to the high label rate (1x) (high rate) and 1/10th of that amount (0.1x) (low rate) dissolved in 378.5 liters of water. Lambda-cyhalothrin was highly toxic to D. brevis nymphs and adults at both rates, whereas both rates of novaluron were highly toxic to nymphs. Cyantraniliprole, chlorantraniliprole, and novaluron were less toxic to adults, and chlorantraniliprole and spinetoram were less toxic to nymphs. Both rates of spinetoram caused significant mortality to adults. Fecundity of adult females was affected negatively by the high rates of either novaluron or spinetoram, whereas the fertility was affected only by the high rate of novaluron. The high rate of spinetoram reduced survival of nymphs. Adults treated with spinetoram had reduced longevity. Cyantraniliprole caused some mortality to nymphs and affected their survival. Both rates of sulfur were toxic to nymphs and affected emergence to adults. The mixture of copper hydroxide and mancozeb was less toxic to D. brevis. Neither adult longevity nor sex ratio was affected by the fungicides. The r values for D. brecis treated with lambda-cyhalothrin, novaluron, spinetoram, and sulfur were low, indicating that these products may have negative impact on population growth.

  19. Weedy hosts and prevalence of potential leafhopper vectors (Hemiptera: Cicadellidae) of a phytoplasma (16SrIX group) associated with Huanglongbing symptoms in citrus groves.

    Science.gov (United States)

    Marques, R N; Teixeira, D C; Yamamoto, P T; Lopes, J R S

    2012-04-01

    Huanglongbing (HLB) is a severe citrus (Citrus spp.) disease associated with the bacteria genus Candidatus Liberibacter, detected in Brazil in 2004. Another bacterium was found in association with HLB symptoms and characterized as a phytoplasma belonging to the 16SrIX group. The objectives of this study were to identify potential leafhopper vectors of the HLB-associated phytoplasma and their host plants. Leafhoppers were sampled every other week for 12 mo with sticky yellow cards placed at two heights (0.3 and 1.5 m) in the citrus tree canopy and by using a sweep net in the ground vegetation of two sweet orange, Citrus sinensis (L.) Osbeck, groves infected by the HLB-phytoplasma in São Paulo state. Faunistic analyses indicated one Agalliinae (Agallia albidula Uhler) and three Deltocephalinae [Balclutha hebe (Kirkaldy), Planicephalus flavicosta (Stål), and Scaphytopius (Convelinus) marginelineatus (Stål)] species, as the most abundant and frequent leafhoppers (Hemiptera: Cicadellidae). Visual observations indicated an association of leafhopper species with some weeds and the influence of weed species composition on leafhopper abundance in low-lying vegetation. S. marginelineatus and P. flavicosta were more frequent on Sida rhombifolia L. and Althernantera tenella Colla, respectively, whereas A. albidula was observed more often on Conyza bonariensis (L.) Cronq. and B. hebe only occurred on grasses. DNA samples of field-collected S. marginelineatus were positive by polymerase chain reaction and sequencing tests for the presence of the HLB-phytoplasma group, indicating it as a potential vector. The association of leafhoppers with their hosts may be used in deciding which management strategies to adopt against weeds and diseases in citrus orchards.

  20. Phytoreovirus-like sequences isolated from salivary glands of the glassy-winged sharpshooter Homolodisca vitripennis (Hemiptera: Cicadellidae)

    International Nuclear Information System (INIS)

    Katsar, C.S.; Hunter, W.B.; Sinisterra, X.H.

    2007-01-01

    The salivary glands of the Glassy-winged sharpshooter (GWSS), Homalodisca vitripennis Germar 1821, (syn. H. coagulata, Hemiptera: Cicadellidae) were collected and used to produce a cDNA library. Examination by BLASTX analyses identified 2 viral sequences, one a 610-base pair fragment and a second 839-base pair fragment, both of which had significant homology to viruses within the genus Phytoreovirus. Resequencing of the fragments confirmed sequence validities. These sequences were used for in silico protein translation and BLASTP analysis confirming the established homology. While the GWSS is the primary vector of Pierce's disease of grapes, this is the first report that GWSS may be a vector of a phytoreoviruses. Phylogenetic and homology comparisons with BLASTX, BLASTP, and PAUP analyses indicated that the viral sequences isolated from GWSS were closely related to the viruses in the Family Reoviridae, Genus Phytoreovirus, specifically Rice Dwarf Phytoreovirus (RDV). RDV is the only plant reovirus that is not limited to the phloem. Phytoreoviruses are transmitted in a propagative manner by cicadellid leafhoppers (Hemiptera: Cicadellidae), which acquire and transmit them during feeding. Phytoreoviruses have been reported from Agallian, Agalliopsis, Nephotettix, and Recilia, genera of leafhoppers, with evidence for transovarial transmission. The GWSS, although considered to feed primarily from the xylem, ingests from other plant tissues, such as the phloem and mesophyll during probing similar to other leafhoppers. The feeding behavior and wide host range of the GWSS provides an overlapping condition for these two organisms, leafhopper and virus. GWSS will feed from grasses as a transitory host, and on herbaceous and woody plants as primary hosts, which may favor the acquisition and transmission of Phytoreovirus by this leafhopper. Monitoring for an increase of Phytoreovirus spread in graminaceous crops that are in proximity to vineyards or tree crop orchards, where

  1. Mesoionic Pyrido[1,2-a]pyrimidinone Insecticides: From Discovery to Triflumezopyrim and Dicloromezotiaz.

    Science.gov (United States)

    Zhang, Wenming

    2017-09-19

    One of the greatest global challenges is to feed the ever-increasing world population. The agrochemical tools growers currently utilize are also under continuous pressure, due to a number of factors that contribute to the loss of existing products. Mesoionic pyrido[1,2-a]pyrimidinones are an unusual yet very intriguing class of compounds. Known for several decades, this class of compounds had not been systemically studied until we started our insecticide discovery program. This Account provides an overview of the efforts on mesoionic pyrido[1,2-a]pyridinone insecticide discovery, beginning from the initial high throughput screen (HTS) discovery to ultimate identification of triflumezopyrim (4, DuPont Pyraxalt) and dicloromezotiaz (5) for commercialization as novel insecticides. Mesoionic pyrido[1,2-a]pyrimidinones with a n-propyl group at the 1-position, such as compound 1, were initially isolated as undesired byproducts from reactions for a fungicide discovery program at DuPont Crop Protection. Such compounds showed interesting insecticidal activity in a follow-up screen and against an expanded insect species list. The area became an insecticide hit for exploration and then a lead area for optimization. At the lead optimization stage, variations at three regions of compound 1, i.e., side-chain (n-propyl group), substituents on the 3-phenyl group, and substitutions on the pyrido- moiety, were explored with many analogues prepared and evaluated. Breakthrough discoveries included replacing the n-propyl group with a 2,2,2-trifluoroethyl group to generate compound 2, and then with a 2-chlorothiazol-5-ylmethyl group to form compound 3. 3 possesses potent insecticidal activity not only against a group of hopper species, including corn planthopper (Peregrinus maidis (Ashmead), CPH) and potato leafhopper (Empoasca fabae (Harris), PLH), as well as two key rice hopper species, namely, brown planthopper (Nilaparvata lugens (Stål), BPH) and rice green leafhopper (Nephotettix

  2. The cicadas of Argentina with new records, a new genus and fifteen new species (Hemiptera: Cicadoidea: Cicadidae).

    Science.gov (United States)

    Sanborn, Allen F; Heath, Maxine S

    2014-10-11

    within Guyalna bonaerensis (Berg, 1879). Derotettix proseni Torres, 1945 is determined to be a junior synonym of Derotettix wagneri Distant, 1905 syn. n. Dorisiana metcalfi nom. nov. pro Cicada viridis Olivier, 1790 nec Cicada viridis Linnaeus, 1758 is proposed. Tettigades lizeriana Delétang, 1919 is shown to be an invalid name for the purposes of zoological nomenclature. The first records for Argentina of Fidicinoides determinata (Walker, 1858), Fidicinoides vinula (Stål, 1854) comb. n., rev. stat., Prasinosoma fuembuenai Torres, 1963, Ariasa bilaqueata (Uhler, 1903), Ariasa colombiae (Distant, 1892), Carineta boliviana Distant, 1905, Carineta gemella Boulard, 1986, Calyria stigma (Walker, 1850), Selymbria pandora Distant, 1911, Taphura hastifera (Walker, 1858), Taphura misella (Stål, 1854), and Tettigades angularis Torres, 1958 are provided. Ten species are removed from the Argentine cicada fauna. The new records and new species represent a 36% increase in the known cicada fauna. Fifty-eight species (54%) and 10 genera (27%) are currently endemic to Argentina.