Sample records for greenbug schizaphis graminum

  1. Effect of ursolic acid from epicuticular waxes of Jacaranda decurrens on Schizaphis graminum. (United States)

    Varanda, E M; Zúñiga, G E; Salatino, A; Roque, N F; Corcuera, L J


    Ursolic acid from Jacaranda decurrens showed toxicity and feeding deterrency towards the greenbug Schizaphis graminum. Biological activity was determined by analyzing ursolic acid effects on the survival, reproductive index, and population growth rate of the greenbug. Survival and reproductive index decreased in direct proportion to ursolic acid content in the diet. The population growth rate decreased markedly when the aphids were fed on barley leaves sprayed with ursolic acid dissolved in DMSO, in comparison to leaves sprayed only with DMSO. The feeding behavior of the greenbug was also affected by ursolic acid. Ingestion time on diet with 0.1 mM was reduced about 30% in relation to the ingestion time on control diet.

  2. Evaluación de la resistencia a Schizaphis graminum (Hemiptera: Aphididae en cebada Assessment of resistance against Schizaphis graminum (Hemiptera: Aphididae in barley

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    Erica F. Tocho


    Full Text Available El pulgón verde de los cereales, Schizaphis graminum (Rondani, es una de las principales plagas de estos cultivos en el mundo y también presente en Argentina. Si bien el control químico es la práctica más utilizada, el uso de variedades resistentes (uno de los componentes principales del MIP es la estrategia más efectiva y ambientalmente más amigable para el control de plagas. Dado que las plantas presentan distintos mecanismos que les permiten defenderse de los insectos, el objetivo de este trabajo fue caracterizar la resistencia a Schizaphis graminum en una población de líneas recombinantes de cebada, e identificar aquellas con mejores características, portadoras de genes de resistencia a este insecto. La antixenosis fue analizada por la prueba de libre selección de hospederos. La antibiosis se evaluó por los parámetros del ciclo y el desarrollo del áfido y la tolerancia por características de crecimiento de las plantas bajo infestación. Al menos ocho líneas antibióticas fueron más tolerantes que sus testigos, presentando similares pesos secos, área foliar y contenido de clorofila bajo infestación. Estas líneas portadoras de genes de resistencia pueden ser de utilidad en los planes de mejora de la cebada.Greenbug, Schizaphis graminum (Rondani is one of the major pests of cereals around the world that is present in Argentina. Chemical control is the most widely used practice; however, the use of resistant varieties, one of the main components in IPM, is the most effective and environmentally sustainable strategy of control. Since plants have different types of insect resistance that allow them to defend against pests, the aim of the current study was to characterize the resistance to Schizaphis graminum in a population of recombinant inbred lines of barley and to identify lines with improved characteristics that enable the development of commercial cultivars. Antixenosis was studied by the host free choice test. Antibiosis

  3. The integrative effects of population density, photoperiod, temperature, and host plant on the induction of alate aphids in Schizaphis graminum. (United States)

    An, Chunju; Fei, Xiaodong; Chen, Wenfeng; Zhao, Zhangwu


    The wheat aphid Schizaphis graminum (Rondani) displays wing dimorphism with both winged and wingless adult morphs. The winged morph is an adaptive microevolutionary response to undesirable environmental conditions, including undesirable population density, photoperiod, temperature, and host plant. Here we studied the integrative effects of population density, photoperiod, temperature, and host plant on the induction of alate aphids in S. graminum. The present results show that these four factors all play roles in inducing alate aphids in S. graminum but population density is the most important under almost all circumstances. In importance, population density is followed by photoperiod, host plant, and temperature, in that order. These results indicate that ambient environmental factors are highly important to stimulation of alate aphids in S. graminum, especially when population density reaches 64 individuals per leaf. © 2012 Wiley Periodicals, Inc.

  4. Biology and predatory potential of coccinella septempunctata linn. on schizaphis graminum aphid under controlled conditions

    International Nuclear Information System (INIS)

    Rauf, M.; Gillani, W.A.; Haq, E.U.; Khan, J.; Ali, A.


    The biology and predatory potential of Coccinella septempunctata (Linn.) were studied on aphid, Schizaphis graminum (Rondani) at three constant temperatures 20+-1 degree C, 25+-1 degree C and 30+-1 degree C in Insectary-Bio Control Laboratories, National Agricultural Research Centre (NARC), Islamabad. The results revealed that incubation period of C. septempunctata was 5.12, 3.62 and 3.20 days with 75.6%, 82.0% and 71.2% hatchability, respectively. The larval durations were 29.5, 15.9 and 8.1 days with predatory potential of 573.7, 575.0 and 667.8 aphids per larvae. The results indicated that with increasing temperature, develop-mental duration decreases significantly. The pupal developmental duration was 14.0, 9.2 and 5.2 days, respectively which are significantly different from each other. The adult male and female longevity were 44.7, 37.7, 30.0 and 60.3, 58.9 and 43.7 days. Fecundity rate of females were 123.5, 251.5 and 293.2 eggs per female, respectively. This indicates that adult male and female developmental duration, female fecundity rate were significantly different from each other at three constant temperatures. Maximum female and male predatory potential was 3262.8 and 2571.7 aphids at 25 +-1 degree C while minimum was 2276.8 and 1890.6 aphids, respectively. (author)

  5. Genomic and proteomic analysis of Schizaphis graminum reveals cyclophilin proteins are involved in the transmission of cereal yellow dwarf virus.

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    Cecilia Tamborindeguy

    Full Text Available Yellow dwarf viruses cause the most economically important virus diseases of cereal crops worldwide and are transmitted by aphid vectors. The identification of aphid genes and proteins mediating virus transmission is critical to develop agriculturally sustainable virus management practices and to understand viral strategies for circulative movement in all insect vectors. Two cyclophilin B proteins, S28 and S29, were identified previously in populations of Schizaphisgraminum that differed in their ability to transmit the RPV strain of Cereal yellow dwarf virus (CYDV-RPV. The presence of S29 was correlated with F2 genotypes that were efficient virus transmitters. The present study revealed the two proteins were isoforms, and a single amino acid change distinguished S28 and S29. The distribution of the two alleles was determined in 12 F2 genotypes segregating for CYDV-RPV transmission capacity and in 11 genetically independent, field-collected S. graminum biotypes. Transmission efficiency for CYDV-RPV was determined in all genotypes and biotypes. The S29 isoform was present in all genotypes or biotypes that efficiently transmit CYDV-RPV and more specifically in genotypes that efficiently transport virus across the hindgut. We confirmed a direct interaction between CYDV-RPV and both S28 and S29 using purified virus and bacterially expressed, his-tagged S28 and S29 proteins. Importantly, S29 failed to interact with a closely related virus that is transported across the aphid midgut. We tested for in vivo interactions using an aphid-virus co-immunoprecipitation strategy coupled with a bottom-up LC-MS/MS analysis using a Q Exactive mass spectrometer. This analysis enabled us to identify a third cyclophilin protein, cyclophilin A, interacting directly or in complex with purified CYDV-RPV. Taken together, these data provide evidence that both cyclophilin A and B interact with CYDV-RPV, and these interactions may be important but not sufficient to mediate

  6. Transcriptional analysis of defense mechanisms in upland tetraploid switchgrass to greenbugs. (United States)

    Donze-Reiner, Teresa; Palmer, Nathan A; Scully, Erin D; Prochaska, Travis J; Koch, Kyle G; Heng-Moss, Tiffany; Bradshaw, Jeffrey D; Twigg, Paul; Amundsen, Keenan; Sattler, Scott E; Sarath, Gautam


    Aphid infestation of switchgrass (Panicum virgatum) has the potential to reduce yields and biomass quality. Although switchgrass-greenbug (Schizaphis graminum; GB) interactions have been studied at the whole plant level, little information is available on plant defense responses at the molecular level. The global transcriptomic response of switchgrass cv Summer to GB was monitored by RNA-Seq in infested and control (uninfested) plants harvested at 5, 10, and 15 days after infestation (DAI). Differentially expressed genes (DEGs) in infested plants were analyzed relative to control uninfested plants at each time point. DEGs in GB-infested plants induced by 5-DAI included an upregulation of reactive burst oxidases and several cell wall receptors. Expression changes in genes linked to redox metabolism, cell wall structure, and hormone biosynthesis were also observed by 5-DAI. At 10-DAI, network analysis indicated a massive upregulation of defense-associated genes, including NAC, WRKY, and MYB classes of transcription factors and potential ancillary signaling molecules such as leucine aminopeptidases. Molecular evidence for loss of chloroplastic functions was also detected at this time point. Supporting these molecular changes, chlorophyll content was significantly decreased, and ROS levels were elevated in infested plants 10-DAI. Total peroxidase and laccase activities were elevated in infested plants at 10-DAI relative to control uninfested plants. The net result appeared to be a broad scale defensive response that led to an apparent reduction in C and N assimilation and a potential redirection of nutrients away from GB and towards the production of defensive compounds, such as pipecolic acid, chlorogenic acid, and trehalose by 10-DAI. By 15-DAI, evidence of recovery in primary metabolism was noted based on transcript abundances for genes associated with carbon, nitrogen, and nutrient assimilation. Extensive remodeling of the plant transcriptome and the production of

  7. Incidence and distribution of insect pests in rain-fed wheat in eastern ...

    African Journals Online (AJOL)

    The greenbug (Schizaphis graminum Rondani) and the green stink bug (Nezara viridula L.) were recorded only in Uganda. The general aphid predators Cheilomenes spp., spiders, lacewings and the parasitoid Aphidius spp. were the natural enemies of aphids found in Kenyan wheat. However, the density of these natural ...

  8. Developing new markers and QTL mapping for greenbug resistance in sorghum [Sorghum bicolor (L.) Moench (United States)

    Greenbug is a major damaging insect to sorghum production in the United States. Among various virulent greenbug biotypes, biotype I is the most predominant and severe for sorghum. To combat with the damaging pest, greenbug resistant sources were obtained from screening sorghum germplasm collection...

  9. First record of the adventive oriental aphid Schizaphis piricola (Matsumura, 1917 (Hemiptera, Aphididae in Europe

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    Nicolás Pérez-Hidalgo


    Full Text Available The oriental aphid Schizaphis piricola Matsumura, is recorded for the first time in Europe, on the ornamental pear tree Pyrus calleryana in landscaped areas in Madrid (Spain. Data on the morphology of the primary host (apterous and alate fundatrigeniae and fundatrices, and their biology and distribution are given. The keys for identifying species of Schizaphis (Schizaphis in the Iberian Peninsula are updated. Two species of aphids are also recorded for the first time on Pyrus calleryana: S. piricola and Aphis pomi.

  10. Registration of STARS 1501B and STARS 1502B barley germplasm with Rsg2 resistance to greenbug (United States)

    STARS 1501B (Reg. No. GP- , PI 675335) greenbug-resistant, six-rowed, spring, feed barley (Hordeum vulgare L.) germplasm and STARS 1502B (Reg. No. GP-, PI 675336) greenbug-resistant, six-rowed, winter, feed barley germplasm, tested as GR 001 and GR 010 respectively, were developed and released by US...

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    African Journals Online (AJOL)

    and central Africa. Annual Review of. Entomology 31:479-509. Dreyer, D.L. and Jones, K.C. 1981. Feeding deterrency of flavonoids and related phenolics towards Schizaphis graminum and Myzus persicae aphid feeding deterrents in wheat. Phytochemistry 20:2489-2493. Le Rü, B. and Tertuliano, M. 1993. Tolerance of.

  12. Selective and irreversible inhibitors of aphid acetylcholinesterases: steps toward human-safe insecticides.

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    Yuan-Ping Pang

    Full Text Available Aphids, among the most destructive insects to world agriculture, are mainly controlled by organophosphate insecticides that disable the catalytic serine residue of acetylcholinesterase (AChE. Because these agents also affect vertebrate AChEs, they are toxic to non-target species including humans and birds. We previously reported that a cysteine residue (Cys, found at the AChE active site in aphids and other insects but not mammals, might serve as a target for insect-selective pesticides. However, aphids have two different AChEs (termed AP and AO, and only AP-AChE carries the unique Cys. The absence of the active-site Cys in AO-AChE might raise concerns about the utility of targeting that residue. Herein we report the development of a methanethiosulfonate-containing small molecule that, at 6.0 microM, irreversibly inhibits 99% of all AChE activity extracted from the greenbug aphid (Schizaphis graminum without any measurable inhibition of the human AChE. Reactivation studies using beta-mercaptoethanol confirm that the irreversible inhibition resulted from the conjugation of the inhibitor to the unique Cys. These results suggest that AO-AChE does not contribute significantly to the overall AChE activity in aphids, thus offering new insight into the relative functional importance of the two insect AChEs. More importantly, by demonstrating that the Cys-targeting inhibitor can abolish AChE activity in aphids, we can conclude that the unique Cys may be a viable target for species-selective agents to control aphids without causing human toxicity and resistance problems.

  13. Efeito da temperatura sobre o desenvolvimento de Scymnus (Pullus argentinicus (Coleoptera: Coccinellidae Effects of temperature on the development of Scymnus (Pullus argentinicus (Coleoptera: Coccinellidae

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    Terezinha Monteiro dos Santos


    Full Text Available Estudou-se a biologia de Scymnus (Pullus argentinicus Weise sobre a presa Schizaphis graminum a 20, 25 e 30ºC. As temperaturas de 25 e 30ºC foram favoráveis ao desenvolvimento de S. (Pullus argentinicus. O período embrionário médio foi de 3,24 dias e o estádio larval de 8,43 dias a 25ºC. A duração média dos ínstares e os períodos pré-pupal e pupal foram significativamente menores a 25 e 30ºC. O percentual de adultos emergidos foi maior a 30ºC (98% ao passo que a 20ºC houve 82% de emergência.The biology of Scymnus (Pullus argentinicus Weise on Schizaphis graminum at the temperatures 20, 25 and 30ºC was studied. The temperatures of 25 and 30ºC were favorable to S. (Pullus argentinicus development. The average of the incubation period was 3.24 days and the larval development was 8.43 days at 25ºC. The duration of the instars and pre-pupal and pupal periods was significantly shorter at 25 and 30ºC. The percentage of emerging adults was higher at 30ºC (98% while at 20ºC this percentual was 82%.

  14. Aspectos biológicos de Harmonia axyridis alimentada com duas espécies de presas e predação intraguilda com Eriopis connexa Biological aspects of Harmonia axyridis fed on two prey species and intraguild predation with Eriopis connexa

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    Natália Ribeiro Pereira dos Santos


    Full Text Available O objetivo deste trabalho foi determinar os aspectos biológicos de Harmonia axyridis, alimentada com duas espécies de presas, e a ocorrência de predação intraguilda com Eriopis connexa. Larvas de H. axyridis foram alimentadas diariamente com ovos de Anagasta kuehniella ou com o pulgão Schizaphis graminum. Adultos da joaninha foram separados em dez casais que receberam o mesmo tipo de alimento da fase larval. Na avaliação da predação, uma larva de quarto instar de cada espécie foi mantida na presença ou ausência de abrigo e de ovos de A. kuehniella. A fase larval de H. axyridis durou 10,2 e 8,9 dias, quando alimentada com A. kuehniella e S. graminum, respectivamente. A sobrevivência do predador, em fase imatura, variou de 70 a 100%. A joaninha apresentou período de oviposição de 47,3 e 51,7 dias, com 887,6 e 822,5 ovos, ao se alimentar de A. kuehniella e S. graminum, respectivamente. A longevidade das fêmeas foi de 74,1 e 76,2 dias e a dos machos de 67,3 e 70,3 dias, em A. kuehniella e S. graminum, respectivamente. H. axyridis atuou como predador intraguilda e foi a espécie dominante na competição com E. connexa.The objective of this work was to determine the biological aspects Harmonia axyridis, fed on two prey species, and the occurrence of intraguild predation with Eriopis connexa. Larvae of H. axyridis were fed daily with Anagasta kuehniella eggs or Schizaphis graminum aphid. Adults of H. axyridis were separated in ten couples which received the same food type of the larval stage. For the estimation of predation, a fourth instar larva of each species was maintained in the presence or absence of shelter and eggs of A. kuehniella. The larval stage lasted 10.2 days, when H. axyridis fed on A. kuehniella eggs, and 8.9 days when reared with S. graminum. The survival of predator during immature stages ranged from 70 to 100%. H. axyridis had an oviposition period of 47.3 and 51.7 days, laying a total of 887.6 and 822.5 eggs

  15. Biological aspects of Eriopis connexa (Germar (Coleoptera: Coccinellidae fed on different insect pests of maize (Zea mays L. and sorghum [Sorghum bicolor L. (Moench.

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    RB Silva

    Full Text Available Eriopis connexa (Germar (Coleoptera: Coccinellidae occurs in several countries of South America and its mass rearing is important for biological control programmes. This work evaluated biological aspects of E. connexa larva fed on eggs of Anagasta kuehniella (Zeller (Lepidoptera: Pyralidae and Spodoptera frugiperda (J. E. Smith (Lepidoptera: Noctuidae frozen for one day, fresh eggs of Diatraea saccharalis (Fabricius (Lepidoptera: Pyralidae, S. frugiperda newly-hatched caterpillars, nymphs of Rhopalosiphum maidis (Fitch and Schizaphis graminum (Rondani (Hemiptera: Aphididae. Duration of larva, pupa and larva to adult stages differed among prey offered, whereas the prepupa stage was similar. Larva, pupa, prepupa and larva to adult viabilities were equal or major of 87.5% in all prey, except for larva fed on newly-hatched larvae of S. frugiperda. Eriopis connexa has good adaptation to different prey corroborating its polyphagous feeding habit, which evidences the potential of this natural enemy for controlling corn and sorghum pests.

  16. Indigenous Aphid Predators Show High Levels of Preadaptation to a Novel Prey, Melanaphis sacchari (Hemiptera: Aphididae). (United States)

    Colares, Felipe; Michaud, J P; Bain, Clint L; Torres, Jorge B


    The performance of four aphid predators, Hippodamia convergens Guerin-Meneville, Coleomegilla maculata DeGeer, Chrysoperla carnea Stephens and Orius insidiosus Say was compared on three prey species: Schizaphis graminum Rondani, Melanaphis sacchari (Zehntner), and Ephestia kuehniella Zeller eggs. Species predatory in both life stages (all except Ch. carnea) were reared on E. kuehniella eggs and switched to aphid prey for assessment of reproduction. Differences were greater between the E. kuehniella and aphid diets than between the two aphid species. Juvenile survival was high for all predators on all prey, except for O. insidiosus, which had survival on E. kuehniella > S. graminum > M. sacchari. The fastest development of Ch. carnea and O. insidiosus was obtained on E. kuehniella, whereas H. convergens developed fastest on S. graminum, and C. maculata did not differ among diets. S. graminum also yielded the largest H. convergens adults, whereas the largest adults of other predators were obtained on E. kuehniella. Female fecundity and egg viability were similarly high on both aphid diets for H. convergens and C. maculata, whereas, on E. kuehniella, 50% of the former entered reproductive diapause and the latter species had reduced fecundity. Reproductive success of Ch. carnea was S. graminum = M. sacchari > E. kuehniella, but it was similar among treatments for O. insidiosus, although female infertility ranged from 25 to 37.5%. We concluded that all the predators studied are preadapted to utilize sugarcane aphid as prey and have excellent potential to provide sustainable biological control of this newly invasive pest. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email:

  17. Interacción genotipo-ambiente en avena sativa l: utilizando los modelos AMMI y factorial de correspondencias Genotype-environment interaction in avena sativa l: employing AMMI and factorial correspondence models

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    Horacio Abel Acciaresi


    Full Text Available El objetivo fue (i determinar la presencia de interacción genotipo-ambiente (IGA en la producción forrajera de avena (Avena sativa L. de genotipos tolerantes y no tolerantes a Schizaphis graminum empleando un número bajo de ambientes en la provincia de Buenos Aires (Argentina mediante los modelos de efectos principales aditivos e interacción multiplicativa (AMMI y análisis factorial de correspondencias (AFC y (ii comparar los resultados obtenidos por ambos métodos. Los ensayos se condujeron en La Dulce (Argentina y La Plata (Argentina (1993, 1994 y 1995. Se evaluaron 12 genotipos (comerciales y líneas avanzadas en 12 ambientes (combinación de localidad, años y cortes. Los factores ambiente, genotipo e interacción explicaron un 41,15% (pThe objective of this study was (i to determine the presence of genotype-environment interaction (GXE in Avena sativa l. for above dry matter yield of Schizaphis graminun tolerant and non-tolerant genotypes according to two different models: additive main effects and multiplicative interaction (AMMI and factorial correspondence analysis; and (ii to study and compare the results obtained with these models. Twelve genotypes and 12 environments were conducted at La Dulce and La Plata (Argentina during three years (1993, 1994 and 1995. The environment (E, genotype (G and GxE factors explained a 41.15%, 7.88% and 36.36% of the total sum of square, respectively. The first three axes of principal component analysis of AMMI were highly significant (p<0.001, explaining a 57.99%, 29.03% and 6.27% of interaction sum of square. The first three factorial correspondence coordinates accounted for 58.98%, 29.58% and 5.60% of the interaction sum of square. The relationships between tolerant genotypes-first clipping environments and non-tolerant genotypes-second clipping environments were reflected in the biplots of both models. The simultaneous use of AMMI and factorial correspondence analysis appeared as a useful

  18. Preliminary Research on the Wheat Pests and on Their Integrated Control during 2015-2016, at Agricultural Research-Development Station Turda

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    Ionel Dragoş DĂRAB


    Full Text Available In Transylvania, the evolution of wheat insect pests is strongly influenced by the ecotehnological conditions, by climate change and current technology (Malschi, 2009 Malschi et al., 2015. The paper presents the dynamics and importance of the main pests of wheat (thrips, aphids, leafhoppers, wheat flies, cereals sunbugs, investigated under the integrated pest control system suitable of the area. During 2015-2016, the investigations were conducted at the Agricultural Research and Development Station Turda, from the wheat no tillage cultural system with cereal rotation of three years and applying all zonal recommendations of technology and phytosanitary complex. The pest monitoring was performed based on the samples collected with entomological net, by decadal 100 sweep-net catches/sample. The study data shows the danger of the attack of abundant populations of wheat flies (Phorbia securis, Delia coarctata, Opomyza florum, Oscinella frit etc.; wheat fleas (Chaetocnema aridula and cereal leaf beetle (Oulema melanopa; leafhoppers (Psammotettix alienus, Javesella pellucida, Macrosteles laevis; aphids (Sitobion avenae, Schizaphis graminum, Rhopalosiphum padi; thrips (Haplothrips tritici, sunbugs (Eurygaster maura, Aelia acuminata etc., and the necessity of applying insecticide treatments on the vegetation. Since 2015, a stronger impact of global warming on the wheat pests structure (% are found. This change began on the last ten years. The importance of cereal sunbugs is increasing, well as the importance of the wheat flies, aphids and leafhoppers, which requires professional study on the pest dynamics and adequate integrated control of wheat pests.

  19. Egg Cannibalism and its Life History Consequences Vary with Life Stage, Sex, and Reproductive Status in Hippodamia convergens (Coleoptera: Coccinellidae). (United States)

    Bayoumy, Mohamed H; Michaud, J P


    Egg cannibalism is common in Coccinellidae, but its biological consequences have not been fully explored. We examined egg cannibalism by neonates, fourth instars, and adults of Hippodamia convergens Guerin-Meneville for effects on development, reproduction, and progeny fitness. We also tested female adults for ability to avoid cannibalizing their own eggs and first-instar larvae, and both sexes for changes in cannibalism propensity following mating, all in the presence of ad libitum food [larvae: eggs of Ephestia kuehniella Zeller (Lepidoptera: Pyralidae), adults: Schizaphis graminum (Rondani)]. Cannibalism by neonates reduced developmental time and increased male body size. Cannibalism in the fourth instar accelerated pupation and led to the production of eggs that hatched faster, regardless of which parent cannibalized. However, egg fertility was improved only by maternal cannibalism in the fourth instar. Females recognized their own egg clusters, sometimes added eggs to them, and preferentially cannibalized nonfilial clusters. Most gravid females cannibalized a first-instar larva within 30 min, whether filial or not. Adult egg cannibalism was similar for virgin males and females, but declined after mating in males, and increased in females, although it had no effect on fecundity or fertility. Daughters of cannibal pairs were heavier than those of other mating combinations, but offspring of noncannibal parents had the fastest development. Reproductive females appeared to use egg cannibalism to reduce risk for their own eggs, increasing the number cannibalized with the number laid. Thus, egg cannibalism in coccinellids varies with life stage, sex, and reproductive condition, independent of food availability, and benefits are life stage specific. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email:

  20. Comparative role of neem seed extract, moringa leaf extract and imidacloprid in the management of wheat aphids in relation to yield losses in Pakistan (United States)

    Shah, Farhan Mahmood; Razaq, Muhammad; Han, Peng; Chen, Julian


    Wheat being staple food of Pakistan is constantly attacked by major wheat aphid species, Schizaphis graminum (R.), Rhopalosiphum padi (L.) and Sitobion avenae (F.). Due to concern on synthetic chemical use in wheat, it is imperative to search for alternative environment- and human- friendly control measures such as botanical pesticides. In the present study, we evaluated the comparative role of neem seed extract (NSE), moringa leaf extract (MLE) and imidacloprid (I) in the management of the aphid as well as the yield losses parameters in late planted wheat fields. Imidacloprid reduced significantly aphids infestation compared to the other treatments, hence resulting in higher yield, particularly when applied with MLE. The percentages of yield increase in I+MLE treated plots over the control were 19.15–81.89% for grains per spike, 5.33–37.62% for thousand grain weight and 27.59–61.12% for yield kg/ha. NSE was the second most effective control measure in suppressing aphid population, but the yield protected by NSE treatment over the control was comparable to that by imidacloprid. Population densities of coccinellids and syrphids in the plots treated with NSE-2 were higher than those treated with imidacloprid in two out of three experiments during 2013–14. Low predator density in imidacloprid-treated plots was attributed to the lower availability of prey aphids. The efficacy of NSE against aphids varied depending on degree of synchronization among the application timing, the activity of aphids, crop variety and environmental conditions. Despite that, we suggested NSE to be a promising alternative botanical insecticide compared to the most commonly recommended imidiacloprid. Further studies should consider the side effects of biopesticides on non-target organisms in order to provide better management practices in the field. PMID:28953894

  1. Economic evaluation of the effects of planting date and application rate of imidacloprid for management of cereal aphids and barley yellow dwarf in winter wheat. (United States)

    Royer, T A; Giles, K L; Nyamanzi, T; Hunger, R M; Krenzer, E G; Elliot, N C; Kindler, S D; Payton, M


    The effects of planting date and application rate of imidacloprid for control of Schizaphis graminum Rondani, Rhopalosiphum padi L. (Homoptera: Aphididae), and barley yellow dwarf virus (BYDV) in hard red winter wheat were studied. The first experiment was conducted from 1997 to 1999 at two locations and consisted of three planting dates and four rates of imidacloprid-treated seed. The second experiment was conducted from 2001 to 2002 in Stillwater, OK, and consisted of two varieties of hard red winter wheat seed and four rates of imidacloprid. Aphid densities, occurrence of BYDV, yield components, and final grain yield were measured, and yield differences were used to estimate the economic return obtained from using imidacloprid. In the first study, aphid populations responded to insecticide rate in the early and middle plantings, but the response was reduced in the late planting. Yields increased as insecticide rate increased but did not always result in a positive economic return. In the second study, imidacloprid seed treatments reduced aphid numbers and BYD occurrence, protected yield, and resulted in a positive economic return. The presence of aphids and BYDV lowered yield by reducing fertile head density, total kernel weight, and test weight. Whereas the application of imidacloprid seed treatments often provided positive yield protection, it did not did not consistently provide a positive economic return. A positive economic return was consistently obtained if the cereal aphid was carrying and transmitting BYDV and was more likely to occur if wheat was treated with a low rate if imidacloprid and planted in a "dual purpose" planting date window.

  2. Quality of different aphids as hosts of the parasitoid Lysiphlebus testaceipes (Cresson) (Hymenoptera: Braconidae, Aphidiinae); Qualidade de diferentes especies de pulgoes como hospedeiros do parasitoide Lysiphlebus testaceipes (Cresson) (Hymenoptera: Braconidae, Aphidiinae)

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    Silva, Robson J.; Bueno, Vanda H.P. [Universidade Federal de Lavras, MG (Brazil). Dept. de Entomologia]. E-mail:; Sampaio, Marcus V.[Universidade Federal de Uberlandia (UFU), MG (Brazil). Inst. de Ciencias Agrarias]. E-mail:


    Lysiphlebus testaceipes (Cresson) has a broad aphid host range; however the quality of these preys may interfere in its biological feature. This study aimed to evaluate the quality of three Macrosiphini, Brevicoryne brassicae (L.), Lipaphis erysimi (Kaltenbach) and Myzus persicae (Sulzer), and three Aphidini Schizaphis graminum (Rondani) Rhopalosiphum maidis (Fitch) and Aphis gossypii Glover as hosts to L. testaceipes and to determine the relation possible of host preference, of size and quality of the host. The tests were carried out in climatic chamber at 25 {+-} 1 deg C, RH 70 {+-} 10% and 12h photophase. The parasitoid did not oviposite in B. brassicae and L. erysimi, while the other species were nutritionally suitable to the parasitoid. L. testaceipes showed preference for aphids from tribe Aphidini and these hosts presented better quality to the parasitoid when compared to Macrosiphini. Interactions among size, preference and quality between the Aphidini were found. L. testaceipes showed preference (parasitism rate 76.7%) for R. maidis, the bigger host (hind tibia with 0.281 mm). This host provided bigger size (hind tibia with 0.49 mm) and higher emergence rate (95.6%) to the parasitoid when compared to A. gossypii (parasitism rate of 55.7%). Also the smaller host A. gossypii (0.266 mm) provided smaller size hind tibia (0.45 mm) and higher mortality of the parasitoid (emergence rate 72.1%). However, the development time was shorter and the longevity was higher in A. gossypii (6.3 and 5.4 days, respectively) when compared to the host R. maidis (6.7 and 3.8 days, respectively), and not been related to host size. (author)

  3. Aegilops biuncialis partial amphiploid

    African Journals Online (AJOL)



    Jul 20, 2009 ... Heredity, 78: 97-100. Gill BS, Sharma HC, Raupp WJ, Browder LE, Hatchett JH and Harvey. TL (1985). Evaluation of Aegilops species for resistance to wheat powdery mildew, wheat leaf rust, Hessian fly and greenbug. Plant. Breeding, 69: 314-316. Jiang J, Hulbert HS, Gill BS, Ward DC (1996). Interphase ...

  4. Organophosphate insecticide poisoning of Canada geese in the Texas panhandle (United States)

    White, D.H.; Mitchell, C.A.; Wynn, L.D.; Flickinger, Edward L.; Kolbe, E.J.


    Sixteen hundred waterfowl, mostly Canada Geese, died near Etter, Texas, in late January 1981 from anticholinesterase poisoning. Winter wheat in the area of the die-off had been treated with organophosphate insecticides to control greenbugs. Cholinesterase (ChE) levels in brains of a sample of geese found dead were 75% below normal, enough to account for death (Ludke et al. 1975). The gastrointestinal (G I) tracts of geese found dead were packed with winter wheat; gas chromatography techniques identified parathion and methyl parathion in the GI tract contents. Residues of both chemicals were confirmed by mass spectrometry. We recommend that less toxic materials, such as malathion, be used on grain crops when waterfowl are in the vicinity of treatment.

  5. Novel acetylcholinesterase target site for malaria mosquito control.

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    Yuan-Ping Pang


    Full Text Available Current anticholinesterase pesticides were developed during World War II and are toxic to mammals because they target a catalytic serine residue of acetylcholinesterases (AChEs in insects and in mammals. A sequence analysis of AChEs from 73 species and a three-dimensional model of a malaria-carrying mosquito (Anopheles gambiae AChE (AgAChE reported here show that C286 and R339 of AgAChE are conserved at the opening of the active site of AChEs in 17 invertebrate and four insect species, respectively. Both residues are absent in the active site of AChEs of human, monkey, dog, cat, cattle, rabbit, rat, and mouse. The 17 invertebrates include house mosquito, Japanese encephalitis mosquito, African malaria mosquito, German cockroach, Florida lancelet, rice leaf beetle, African bollworm, beet armyworm, codling moth, diamondback moth, domestic silkworm, honey bee, oat or wheat aphid, the greenbug, melon or cotton aphid, green peach aphid, and English grain aphid. The four insects are house mosquito, Japanese encephalitis mosquito, African malaria mosquito, and German cockroach. The discovery of the two invertebrate-specific residues enables the development of effective and safer pesticides that target the residues present only in mosquito AChEs rather than the ubiquitous serine residue, thus potentially offering an effective control of mosquito-borne malaria. Anti-AgAChE pesticides can be designed to interact with R339 and subsequently covalently bond to C286. Such pesticides would be toxic to mosquitoes but not to mammals.

  6. Diversity, frequency, and geographic distribution of facultative bacterial endosymbionts in introduced aphid pests. (United States)

    Sepúlveda, Daniela A; Zepeda-Paulo, Francisca; Ramírez, Claudio C; Lavandero, Blas; Figueroa, Christian C


    Facultative bacterial endosymbionts in insects have been under intense study during the last years. Endosymbionts can modify the insect's phenotype, conferring adaptive advantages under environmental stress. This seems particularly relevant for a group of worldwide agricultural aphid pests, because endosymbionts modify key fitness-related traits, including host plant use, protection against natural enemies and heat tolerance. Aimed to understand the role of facultative endosymbionts on the success of introduced aphid pests, the distribution and abundance of 5 facultative endosymbionts (Hamiltonella defensa, Regiella insecticola, Serratia symbiotica, Rickettsia and Spiroplasma) were studied and compared in 4 cereal aphids (Sitobion avenae, Diuraphis noxia, Metopolophium dirhodum and Schizaphis graminium) and in the pea aphid Acyrthosiphon pisum complex from 2 agroclimatic zones in Chile. Overall, infections with facultative endosymbionts exhibited a highly variable and characteristic pattern depending on the aphid species/host race and geographic zone, which could explain the success of aphid pest populations after their introduction. While S. symbiotica and H. defensa were the most frequent endosymbionts carried by the A. pisum pea-race and A. pisum alfalfa-race aphids, respectively, the most frequent facultative endosymbiont carried by all cereal aphids was R. insecticola. Interestingly, a highly variable composition of endosymbionts carried by S. avenae was also observed between agroclimatic zones, suggesting that endosymbionts are responding differentially to abiotic variables (temperature and precipitations). In addition, our findings constitute the first report of bacterial endosymbionts in cereal aphid species not screened before, and also the first report of aphid endosymbionts in Chile. © 2016 Institute of Zoology, Chinese Academy of Sciences.