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Cherry-oat Aphid (cherry-oat + aphid)

Distribution by Scientific Domains
Life Sciences100%

Kinds of Cherry-oat Aphid

  • bird cherry-oat aphid
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    Selected Abstracts

    Life history of the bird cherry-oat aphid, Rhopalosiphum padi, on transgenic and non-transformed wheat challenged with Wheat streak mosaic virus

    ENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 1 2009
    Edgardo S. Jiménez-Martínez
    Abstract The life history of the bird cherry-oat aphid, Rhopalosiphum padi (L.) (Hemiptera: Aphididae), was studied via laboratory assays on Wheat streak mosaic virus (WSMV)-infected and non-infected transgenic and non-transformed wheat [Triticum aestivum L. (Poaceae)]. Although R. padi is not a WSMV vector, it is known to colonize WSMV-infected wheat plants. Two transgenic soft white winter wheat genotypes, 366-D03 and 366-D8, that express the WSMV coat protein gene, and the WSMV-susceptible non-transformed cultivar Daws were tested. All genotypes showed disease symptoms when infected with WSMV. Whereas plant height was significantly reduced on virus-infected compared to non-infected plants of all genotypes, virus-infected transgenic plants exhibited lower virus titer and lower disease rating scores than Daws. No significant effects of WSMV infection or genotypes were observed on the length of R. padi nymphal development period, nor on their pre-, and post-reproductive periods. Rhopalosiphum padi reproductive period was significantly longer on Daws infected with WSMV than on non-infected plants of this cultivar. In contrast, there were no significant differences in length of R. padi reproductive period between virus-infected and non-infected transgenic plants within a genotype. Rhopalosiphum padi daily fecundity was significantly lower and adult longevity significantly longer on virus-infected than on non-infected plants of all genotypes. Total aphid fecundity and intrinsic rate of increase were not significantly different among treatments. The percentage of winged aphids that developed was greater on WSMV-infected compared to non-infected plants within a genotype. Results indicate that both virus infection status of plants and wheat genotype influence the life history of R. padi. [source]

    Symbiont-mediated changes in Lolium arundinaceum inducible defenses: evidence from changes in gene expression and leaf composition

    NEW PHYTOLOGIST, Issue 3 2007
    Terrence J. Sullivan
    Summary ,,Plants have multiple strategies to deal with herbivory, ranging from chemical or physical defenses to tolerating damage and allocating resources for regrowth. Grasses usually tolerate herbivory, but for some cool-season grasses, their strategy may depend upon their interactions with intracellular symbionts. Neotyphodium endophytes are common symbionts in pooid grasses, and, for some host species, they provide chemical defenses against both vertebrate and invertebrate herbivores. ,,Here, it was tested whether defenses provided by Neotyphodium coenophialum in Lolium arundinaceum (tall fescue) are inducible by both mechanical damage and herbivory from an invertebrate herbivore, Spodoptera frugiperda (fall armyworm), via a bioassay and by quantifying mRNA expression for lolC, a gene required for loline biosysnthesis. ,,Both mechanical and herbivore damage had a negative effect on the reproduction of a subsequent herbivore, Rhopalosiphum padi (bird cherry-oat aphid), and herbivore damage caused an up-regulation of lolC. Uninfected grass hosts also had significantly higher foliar N% and lower C : N ratio compared with infected hosts, suggesting greater allocation to growth rather than defense. ,,For L. arundinaceum, N. coenophialum appears to switch its host's defensive strategy from tolerance via compensation to resistance. [source]

    Rapid phenotypic assessment of bird cherry-oat aphid resistance in winter wheat

    PLANT BREEDING, Issue 3 2007
    B. L. Dunn
    Abstract Rhopalosiphum padi L. causes significant damage to winter wheat (Triticum aestivum L.), even without obvious aboveground symptoms of injury. Our objectives were to develop a juvenile-plant bioassay for bird cherry-oat aphid (BCOA) resistance that allows rapid phenotypic differentiation. Central features of the bioassay include root and shoot weight measurements of 3-week-old seedlings produced in seed germination pouches, a 14-day aphid exposure period, and a non-infested control treatment to establish a baseline for expected biomass per genotype. Cultivars used in bioassay development were ,Illinois Rustproof' and ,Skala', which showed smaller BCOA-induced reductions in biomass than the more susceptible genotypes, ,Patrick' and ,Scout 66'. Mean reductions in root biomass were 48% for ,Patrick' and ,Scout 66', compared with 29% for ,Illinois Rustproof' and ,Skala'. This rapid and repeatable bioassay is extendable to large wheat collections and inbred line populations. [source]

    Recolonisation and distribution of spiders and carabids in cereal fields after spring sowing

    ANNALS OF APPLIED BIOLOGY, Issue 2 2006
    S. Öberg
    Abstract Generalist predators are important for pest suppression during pest establishment because they may occur in the crop before and during pest arrival. However, different crop management practices can have a negative effect on predator populations. If so, there is a need for recolonisation by the predators to the crop fields. An important pest in Sweden is the bird cherry-oat aphid, Rhopalosiphum padi, which migrates to cereal fields in spring. In turn, many cereal fields are spring sown and thus are disturbed by harrowing and sowing a short time before aphid arrival. In this study, three different questions about the populations of spiders and carabids in spring cereal crops were asked. First, does sowing in spring have a negative effect on the predators present in the fields? Second, if sowing has a negative effect on predator populations, do they recolonise the fields before pest arrival? Third, how are the predators distributed in the fields? We found that most carabids and most lycosid spiders were not affected by sowing and were distributed uniformly in the fields after sowing. Most linyphiid spiders were negatively affected by sowing, but then they recolonised the fields and were uniformly distributed in the fields after recolonisation. Thus, many spiders and carabids are present in the fields after sowing in spring and have the opportunity to suppress aphids during their establishment phase, which in turn may prevent a possible outbreak. [source]