Results 201 to 210 of about 127,737 (232)
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Simulation modelling of the population dynamics of cereal aphids
BioSystems, 1985A simulation model explaining the population dynamics of the grain aphid (Sitobion avenae), a serious pest of wheat in Western Europe, is described. The model includes the effects of crop development and some natural enemies on the biology of the aphid.
N Carter
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Spring migration of cereal aphids
Zeitschrift für Angewandte Entomologie, 1984AbstractIn those years when successful overwintering does not occur on cereal crops, the timing of colonization and the number of alatae of the cereal aphids Sitobion avenae and Metopolophium dirhodum entering cereal crops, before the end of flowering (DS 69), are related to the likelihood of an outbreak occurring.The earlier egg hatch of Rhopalosiphum
S. R. LEATHER, K. F. A. WALTERS
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Density dependence in cereal aphid populations
Annals of Applied Biology, 1996SummaryLong sequences of data on the incidence of cereal aphids from five European countries were analysed for evidence of density dependent processes occurring between years. Using a randomisation test (Pollard, Lakhani & Rotheray, 1987), density dependence was revealed in all (16) population censuses of Metopolo‐phium dirhodum, 60% of ...
A F G Dixon
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Detection of resistance to aphids in cereals
Annals of Applied Biology, 1978SUMMARYResistance to Sitobion avenae and Metopolophium dirhodum was assessed by caging aphids on the upper part of mature tillers. Despite variation in the results, considered to be due mainly to differences amongst plants of different ages, certain cultivars consistently supported fewer aphids.
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Aphid Antixenosis Mediated by Volatiles in Cereals
Acta Agriculturae Scandinavica - Section B Soil and Plant Science, 1996 Abstract Experimental results indicate the existence of an inducible system that can temporarily help cereal plants to defend themselves against cereal aphids. The induction is released by volatiles emitted when aphids attack a neighbour plant individual. Similar effects are obtained with mildew attacked plants.
Pettersson Jan +2 more
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Insecticide and Acaricide Tests, 1989
Abstract Barley was planted 29 Apr near Kimberly, Idaho. The soil type was Portneuf silt loam and the field was surface irrigated. Two rates of Asana were applied with a CO2-pressurized backpack sprayer in 50 gal finished spray/acre. The Asana plots and an untreated control plot were replicated 4 times in a randomized complete block ...
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Abstract Barley was planted 29 Apr near Kimberly, Idaho. The soil type was Portneuf silt loam and the field was surface irrigated. Two rates of Asana were applied with a CO2-pressurized backpack sprayer in 50 gal finished spray/acre. The Asana plots and an untreated control plot were replicated 4 times in a randomized complete block ...
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Journal of Chemical Ecology, 1994
The activity and molecular weights of glutathioneS-transferase were studied in three species of cereal aphid:Metopolophium dirhodum, Sitobion avenae, andRhopalosiphum padi. The highest level of glutathioneS-transferase activity was recorded in extracts fromM. dirhodum and the lowest fromS. avenae, and extracts of larvae were more active than those from
B, Leszczynski, M, Matok, A F, Dixon
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The activity and molecular weights of glutathioneS-transferase were studied in three species of cereal aphid:Metopolophium dirhodum, Sitobion avenae, andRhopalosiphum padi. The highest level of glutathioneS-transferase activity was recorded in extracts fromM. dirhodum and the lowest fromS. avenae, and extracts of larvae were more active than those from
B, Leszczynski, M, Matok, A F, Dixon
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Mapping resistance to cereal aphids in barley
Theoretical and Applied Genetics, 1997A set of 150 doubled-haploid (DH) barley (Hordeum vulgare L.) lines derived from the cross of Harrington/TR306 was used to determine the number and chromosomal location of quantitative trait loci (QTLs) controlling resistance to cereal aphids. The experiments were conducted under natural infestation in the field during two growing seasons: 1994 and ...
S. Moharramipour +3 more
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Cereal aphids on maize in southern England
Annals of Applied Biology, 1982SUMMARYIn 1978, 1979 and 1980, counts were made of the numbers of cereal aphids on a maize crop near Fordingbridge, Hampshire, England. Maize plants were selected away from the edge of the crop and the number, morph, species and feeding site of the aphids were recorded. Metopolophium dirhodum and Rhopalosiphum padi were found at densities that exceeded
S. C. HAND, J. R. CARRILLO
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Aphid colonization of spring cereals
Annals of Applied Biology, 1973SUMMARYIn 1970‐1, Metopolophium dirhodum, Rhopalosiphum padi and Sitobion avenae were the commonest alatae trapped from April/May to August, with most in July and early August. The first alatae appeared in the Rothamsted survey suction trap 0–34 days before aphids were found on the cereals, but during May and June no relationship was found between the ...
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