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Effect of silicon applied to wheat plants on the biology and probing behaviour of the greenbug Schizaphis graminum (Rond.) (Hemiptera: Aphididae)
Goussain, Marcio M.;Prado, Ernesto;Moraes, Jair C.;
Neotropical Entomology , 2005, DOI: 10.1590/S1519-566X2005000500013
Abstract: the effect of silicon-treated wheat plants (triticum aestivum l.) on the greenbug, schizaphis graminum (rond.) (hemiptera: aphididae) was evaluated. plants were treated with silicon incorporated to the soil and by foliar spraying. aphid development was evaluated by observing the duration of the pre-reproductive, reproductive and post-reproductive periods, as well as fecundity and longevity. probing behaviour was investigated by using the dc electrical penetration graphs (epg) technique and a "honeydew clock". silica treated plants had a clear adverse effect on aphid development. stylet penetration was not affected by treatments showing no physical barriers by the plant tissue. however, stylet was withdrawn more often on plants treated with silica, resulting in reduction of probing time. sieve elements were reached equally by aphids in all treatments and the insects remained ingesting phloem sap for similar periods. however, honeydew excretion was highly reduced indicating lower sap ingestion rate or higher sap retention inside the body. chemical changes and induced resistance are possibly related to the reduction of aphid performance.
Intera??o silício-imidacloprid no comportamento biológico e alimentar de Schizaphis Graminum (Rond.) (Hemiptera: Aphididae) em plantas de trigo
Costa, Rosane Rodrigues;Moraes, Jair Campos;Costa, Ronelza Rodrigues da;
Ciência e Agrotecnologia , 2009, DOI: 10.1590/S1413-70542009000200014
Abstract: the greenbug schizaphis graminum (rond.) (hemiptera: aphididae) is one of the main pest insects on wheat crop, being capable of leading a plant to death by sap suction and toxin injection, in addition to transmitting viruses. a strategy recommended to the management of aphids on wheat is the use of selective insecticides, mainly in the seed treatment. this way, in this research, the objective was to monitor the feeding behavior of s. graminum on wheat plants treated with silicon and/or imidachloprid, in addition to evaluate some biological features of the insect. the experiment was carried out at the entomology department, ufla, on wheat cultivar embrapa 22, s. graminum, 1% silicic acid, and imidachloprid seed treatment. the biology assay was conduced, starting at 15, 30, and 45 days after the seed germination, and the honeydew excretion was evaluated. the treatments were distributed in factorial scheme 2 (with silicon and without silicon) x 2 (with imidachloprid and without imidachloprid), with 10 replicates. it was observed that the systemic insecticide imidachloprid acts as a deterrent on adults and it is lethal on nymphs of s. graminum up to 45 days after seed treatment. furthermore, the plants treated with silicon showed resistance to s. graminum.
Temporal genotypic diversity of Schizaphis graminum (Rondani 1852) (Hemiptera: Aphididae) in a black oats (Avena strigosa) field
Lopes-da-Silva, Marcelo;Vieira, Luiz Gonzaga Esteves;
Brazilian Archives of Biology and Technology , 2010, DOI: 10.1590/S1516-89132010000400021
Abstract: the aim of this work was to analyze the clonal diversity variation in schizaphis graminum during a complete phenological cycle of black oats (avena strigosa). rapd markers were used for detection of dna polymorphisms of each clonal lineage, derived from a single clone collected weekly during a period of four months, in a crop field of black oats, londrina, paraná, brazil. the monthly genotypic diversity was estimated by shannon information index (h). only four genotypes were distinguished from 122 specimens, with one of them overly predominant in all sampling dates (>60%). another genotype, apparently a later colonizer, rapidly reached greater frequency than other genotypes on the second and third month. the results of this work suggested that temporal genotypic diversity of s. graminum assessed by rapd markers was small and less variable than the genetic variation found at geographical scale.
Effect of Different Constant Temperatures on Biology of Schizaphis Graminum (Rondani) (Hemiptera: Aphididae) on Barley, Hordeum Vulgare L. (Poaceae) in Iran
Nastaran Tofangsazi, Katayoon Kheradmand, Shahram Shahrokhi, Ali A. Talebi
Journal of Plant Protection Research , 2012, DOI: 10.2478/v10045-012-0052-1
Abstract: The temperature dependent biology of greenbug, Schizaphis graminum Rondani on Kavir barley cultivar was studied at seven constant temperatures including 10, 15, 19, 22, 26, 31, and 33±1°C, 70% relative humidity (RH), and a photoperiod of 16:8 (L:D) hours. The period of immature development ranged between 6.60 days at 26°C to 28.56 days at 10°C, respectively. All tested aphids failed to develop at 33°C. The calculated rm and λ values were significantly the highest at 26°C and lowest at 10°C, respectively. The mean generation time and doubling time of S. graminum decreased linearly by increasing the temperature from 10 to 26°C. Additionally, the total number of offsprings per female was extremely low at 10 and 31°C, contrary to the highest and lowest values of life expectancy at 10°C (41.73 days) and 31°C (7.66 days), respectively. The results of the present study revealed that temperature had great effects on biology of S. graminum, which was never previously studied on barley in Iran.
Characterization and genetic relationships among Brazilian biotypes of Schizaphis graminum (Rondani) (Hemiptera: Aphididae) using RAPD markers
Lopes-da-Silva, Marcelo;Tonet, Gabriela E.L.;Vieira, Luiz G.E.;
Neotropical Entomology , 2004, DOI: 10.1590/S1519-566X2004000100009
Abstract: the greenbug schizaphis graminum (rondani) is one of the most important cereals pests in the world. within populations of this species, several biotypes, which are clones that share same virulence relationships with cultivated plants, can be distinguished. molecular markers have been used to genetically characterize insect populations because they are fast and cost effective. in order to find rapd markers to identify brazilian s. graminum biotypes, nineteen clonal populations of three biotypes (b, c and e) from brazil and three clonal populations from the u.s. were examined. eighteen primers were used to analyze the material, but only six primers revealed polymorphisms and among those, three produced diagnostic band profiles that allowed biotype characterization. using jaccard similarity index and upgma clustering method it was possible to show that biotype b is genetically very distinct from c and e, which are closely related to each other. the biotype c showed the greatest genetic diversity, while biotype e was the least diverse. analysis of molecular variance (amova) showed that genetic variance among clonal populations belonging to the same biotype is smaller than among clonal populations grouped according to their geographical similarity.
Resposta funcional de Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae) alimentada com Schizaphis graminum (Rondani) (Hemiptera: Aphididae)
Fonseca, Alysson R.;Carvalho, César F.;Souza, Brígida;
Anais da Sociedade Entomológica do Brasil , 2000, DOI: 10.1590/S0301-80592000000200013
Abstract: the functional response of chrysoperla externa (hagen) fed on schizaphis graminum (rondani) was studied under five densities of prey. the experimental design was completely randomized with five treatments and ten replications. the tests were conducted in growth chambers at 25 ± 1oc, rh of 70 ± 10% and photophase of 12 hours. consumption increased in function of prey density in all instars. however, consumption tended to stabilize when a pre established average density of prey was offered, except for the first instar, which showed a constant increase in aphid consumption. the duration of the first and third instars and of the larval phase, as a whole, increased in function of the increased availability of prey. the duration of the second instar, however, decreased in function of increased prey availability. the results for the 1st, 2nd and 3rd instars and the larval phase showed a type ii functional response. handling and searching time was evaluated for the average density of offered prey. the lowest searching time was verified for second instar larvae while the first instar showed the highest searching and handling time. handling time dimi-nished progressively with larvae development.
Genetic analysis of greenbug populations of Schizaphis graminum (Hemiptera: Aphididae) from Argentina and Chile based on enzyme variability
Saldúa,Luciana; Tacaliti,María S.; Tocho,Erica; Dixon,Anthony F. G.; Castro,Ana M.;
Revista de la Sociedad Entomol?3gica Argentina , 2011,
Abstract: twenty-nine schizaphis graminum (rondani) populations and sixty clones collected from very contrasting regions of argentina and chile were investigated electrophoretically. a high degree of enzymatic polymorphism was found. the enzymatic structure was described for the esterase system, finding nine different loci. latitudinal stratification was determined and populations were associated into three groups, according to the latitude they were collected from. the 90% of loci resulted polymorphic in the first group and 100% of loci were polymorphic in the rest. observed heterozygosity was lower than expected. no group had fixed alleles according to fsr values; group one had a slight heterozygous excess, while the other groups showed slight positive fsr values, because there was a homozygous excess. according to frt, the third group showed the highest value that was in concordance with the highest gene flow value. three populations could not be included in any group. the α-carboxyl-esterase was always present, also in clones and populations which were located in non agricultural zones, implicating that the insecticide resistance is well spread throughout the argentinean and chilean territory. no relationship was found between the enzymatic patterns and the biotype or with the host species where the aphids were collected from.
Effect of sodium silicate application on the resistance of wheat plants to the green-aphids Schizaphis graminum (Rond.) (Hemiptera: Aphididae)
Basagli, Marco A.B.;Moraes, Jair C.;Carvalho, Geraldo A.;Ecole, Carvalho C.;Gon?alves-Gervásio, Rita de C.R.;
Neotropical Entomology , 2003, DOI: 10.1590/S1519-566X2003000400017
Abstract: the green-aphid schizaphis graminum (rond.) is considered the major important pest of wheat plant, for causing severe injuries to the plants in all phenological crop stages, being able even to cause plant death. the objective of this study was to evaluate the effects of the application of silicon on the resistance of wheat plants to this pest. the experiments were carried out under greenhouse and laboratory conditions. the greenhouse experiment was conducted in a completely randomized experimental design with two treatments, consisting on silicon application and a control (without silicon application) with 10 replications and without environmental control. the laboratory bioassays were conducted under controlled environmental conditions (25 ± 1°c temperature; 70 ± 10% rh; and 12h photophase), in a randomized block experimental design, with a sub-divided plot scheme. the silicon, in the form of sodium silicate solution at 0.4% sio2 was applied in six doses of 50 ml/pot each, at five-day intervals, being the first application performed five days after emergence of the wheat plats. thirty-five days after plants emergence the following evaluations were performed: a) feeding preference in the laboratory; b) feeding preference in the greenhouse; and c) reproduction and development of the green-aphid. application of sodium silicate reduced preference, longevity, and production of nymphs of the green-aphids s. graminum, thus conferring a resistance to wheat plants against this insect-pest.
Biotype characterization and genetic diversity of the greenbug, Schizaphis graminum (Hemiptera: Aphididae), in north Tunisia Caracterización de biotipo y diversidad genética del pulgón verde, Schizaphis graminum (Hemiptera: Aphididae), en el norte de Túnez
IMEN KHARRAT,DHIA BOUKTILA,MAHA MEZGHANI-KHEMAKHEM,HANEM MAKNI
Revista Colombiana de Entomología , 2012,
Abstract: The greenbug Schizaphis graminum, is a major pest of wheat worldwide. Biotype screening of this pest is essential to develop pest management programs. In this research, eight greenbug clones, collected on wheat in the cereal-growing region of Béja (north Tunisia), were used to determine their damage on six reference wheat cultivars. All tested clones shared a unique biotypic profile, similar to biotype C. Moreover, DNA from the tested clones and that from seven reference clones of biotypes C, E, F, G, H, I and K, was analyzed, using 5 RAPD-PCR primers. The UPGMA method clustered samples into two distinct clades: a first one (I) included clones from north Tunisia, which were clearly associated to agricultural biotypes C, E, I and K, while a second clade (II) included non agricultural biotypes F, G and H. Results reported in this paper suggest that resistance genes Gb2, Gb3, Gb4, Gb5 and Gb6 in wheat would be the most efficient if used in wheat improvement programs for resistance against greenbug in Tunisia. El pulgón verde Schizaphis graminum, es una plaga importante del trigo en todo el mundo. La detección de biotipos de esta plaga es esencial para el desarrollo de programas de manejo de plagas. En esta investigación se colectaron, ocho clones del pulgón verde, en el trigo en la región de cultivo de cereales de Béja (norte de Túnez), y se utilizaron para determinar el da o en seis cultivos de trigo de referencia. Todos los clones ensayados comparten un perfil único de biotipo, similar al biotipo C. Además, el ADN de los clones ensayados y de los siete clones de referencia de biotipos C, E, F, G, H, I y K, se analizaron, utilizando 5 RAPD PCR primers. El método UPGMA agrupó las muestras en dos clados: el primero (I) incluye clones del norte de Túnez, que están claramente asociados a los biotipos agrícolas C, E, I y K, mientras que un segundo clado (II) incluyó los biotipos no agrícolas F, G y H. Los resultados sugieren que los genes de resistencia, la Gb2, Gb3, Gb4, Gb5 y Gb6 en el trigo serían los más eficaces si se utilizan en programas de mejoramiento de trigo para la resistencia contra el pulgón verde en Túnez.
Genetic analysis of greenbug populations of Schizaphis graminum (Hemiptera: Aphididae) from Argentina and Chile based on enzyme variability Análisis genético de las poblaciones del pulgón verde Schizaphis graminum (Hemiptera: Aphididae), colectadas en Argentina y Chile, basado en su variabilidad enzimática  [cached]
Luciana Saldúa,María S. Tacaliti,Erica Tocho,Anthony F. G. Dixon
Revista de la Sociedad Entomol?3gica Argentina , 2011,
Abstract: Twenty-nine Schizaphis graminum (Rondani) populations and sixty clones collected from very contrasting regions of Argentina and Chile were investigated electrophoretically. A high degree of enzymatic polymorphism was found. The enzymatic structure was described for the esterase system, finding nine different loci. Latitudinal stratification was determined and populations were associated into three groups, according to the latitude they were collected from. The 90% of loci resulted polymorphic in the first group and 100% of loci were polymorphic in the rest. Observed heterozygosity was lower than expected. No group had fixed alleles according to Fsr values; group one had a slight heterozygous excess, while the other groups showed slight positive Fsr values, because there was a homozygous excess. According to Frt, the third group showed the highest value that was in concordance with the highest gene flow value. Three populations could not be included in any group. The α-carboxyl-esterase was always present, also in clones and populations which were located in non agricultural zones, implicating that the insecticide resistance is well spread throughout the Argentinean and Chilean territory. No relationship was found between the enzymatic patterns and the biotype or with the host species where the aphids were collected from. Veintitrés poblaciones de Schizaphis graminum (Rondani) y sesenta clones colectados en regiones muy contrastantes de la Argentina y Chile fueron investigadas electroforéticamente. Se encontró un alto grado de polimorfismo enzimático. La estructura enzimática fue descripta para el sistema estearasa y se encontraron nueve loci diferentes. Se determinó que existe estratificación latitudinal, las poblaciones fueron asociadas en tres grupos de acuerdo a la latitud donde fueron colectadas. El 90% de los loci resultaron polimórficos en el primer grupo y el 100% de los loci lo fueron en el resto. La heterocigosidad observada fue menor que la esperada. Ningún alelo fue fijado, de acuerdo con el valor del Fsr. El primer grupo tuvo un ligero exceso de heterocigosis, mientras que los demás grupos mostraron valores ligeramente positivos de Fsr, debido al exceso de homocigosis. Con respecto a Frt, el tercer grupo mostró un valor alto que estuvo en concordancia con el alto valor de flujo génico. Tres poblaciones no pudieron ser incluidas en ningún grupo. Las α-carboxil- estearasas siempre estuvieron presentes incluso en clones y poblaciones colectadas en zonas no agrícolas, lo que implica que la resistencia a insecticidas está ampliamente extendida a
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