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Aphid Myzus Persicae (aphid + myzu_persicae)
Kinds of Aphid Myzus Persicae Selected AbstractsHost age and fitness-related traits in a koinobiont aphid parasitoidECOLOGICAL ENTOMOLOGY, Issue 4 2005H. Colinet Abstract., 1.,Trade-offs play a key role in species evolution and should be found in host,parasitoid interactions where the host quality may differ between host age categories. 2.,The braconid wasp, Aphidius ervi, is a solitary endoparasitoid that allows its aphid hosts to continue to feed and grow after parasitisation. The hypotheses that host age influences their quality and that female parasitoids exploit their hosts based on that quality were tested under laboratory conditions using no-choice tests. 3.,Aphidius ervi females accepted the aphid Myzus persicae for oviposition and their progeny developed successfully in all host ages. The fitness-related traits of parasitoids did not increase linearly with the host age in which they developed. Host quality was found to be optimal at intermediate host ages and the females preferred to parasitise these hosts. The shortest progeny development time and a more female-biased sex ratio were observed in hosts of intermediate age. 4.,This study suggests the existence of multiple interactive trade-offs occurring during host,parasitoid interactions according to host age related quality. [source] Nitrogen fertilization effects on Myzus persicae aphid dynamics on peach: vegetative growth allocation or chemical defence?ENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 2 2010Marie-Hélène Sauge Abstract Plant nitrogen (N) fertilization is a common cropping practice that is expected to serve as a pest management tool. Its effects on the dynamics of the aphid Myzus persicae (Sulzer) (Hemiptera: Aphididae) were examined on young peach [Prunus persica (L.) Batsch (Rosaceae)] trees grown under five N treatments, ranging from N shortage to supra-optimal supply for growth. Aphid population increased over time at the three intermediate N levels. It remained stable at the lowest N level and decreased at the highest N level. Four weeks after the start of infestation, the number of aphids displayed a parabolic response to N level. The relationships between N status and parameters of plant vegetative growth (stem diameter) or biomass allocation (lateral-total leaf area and root-shoot ratio) were consistent with responses proposed by models of adaptive plasticity in resource allocation patterns. However, the variation in plant growth predicted aphid population dynamics only partially. Whereas aphid number was positively correlated with plant N status and vegetative growth up to the intermediate N level, it was negatively correlated with plant N status above this level, but not with vegetative growth. The concentrations of primary and secondary (plant defence-related) metabolites in the plant shoots were modified by N treatments: amino acids (main nutritional resource of aphids) and prunasin increased, whereas chlorogenic acid decreased with increasing N availability. Constitutive changes in plant chemistry in response to N fertilization could not directly explain the reduced aphid performance for the highest N level. Nevertheless, the indirect effect of N on the induction of plant defence compounds by aphid feeding warrants further investigation. The study focuses on the feasibility of handling N fertilization to control M. persicae in orchards, but findings may also be relevant for our understanding of the physiological relationships between the host's nutritional status and the requirements of the insect. [source] Studies on the morphometry of the green peach aphid, Myzus persicae (Sulzer) (Homoptera: Aphididae)ENTOMOLOGICAL RESEARCH, Issue 2 2007Potshangbam Bijaya DEVI Abstract Aphids are one of the most important groups of phytophagous insects because of their polyphenism, host alternation, heteroecious behavior and reproductive habits. Laboratory culture of the aphid Myzus persicae on the host plant Brassica pekinensis Hubner was maintained seasonally for biometrical studies. The metric analysis revealed gradual developmental changes from the first instar nymph to the adult stage in size, shape, and a number of characters. The transitional changes were sufficiently distinct to allow differentiation of each of the life stages irrespective of the season. A key to the nymphal stages of the pest is provided. [source] Resting spore formation of aphid-pathogenic fungus Pandora nouryi depends on the concentration of infective inoculumENVIRONMENTAL MICROBIOLOGY, Issue 7 2008Zhi-Hong Huang Summary Resting spore formation of some aphid-pathogenic Entomophthorales is important for the seasonal pattern of their prevalence and survival but this process is poorly understood. To explore the possible mechanism involved in the process, Pandora nouryi (obligate aphid pathogen) interacted with green peach aphid Myzus persicae on cabbage leaves under favourable conditions. Host nymphs showered with primary conidia of an isolate (LC50: 0.9,6.7 conidia mm,2 4,7 days post shower) from air captures in the low-latitude plateau of China produced resting spores (azygospores), primary conidia or both spore types. Surprisingly, the proportion of mycosed cadavers forming resting spores (Pcfrs) increased sharply within the concentrations (C) of 28,240 conidia mm,2, retained high levels at 240,1760, but was zero or extremely low at 0.3,16. The Pcfrs,C relationship fit well the logistic equation Pcfrs = 0.6774/[1 + exp(3.1229,0.0270C)] (r2 = 0.975). This clarified for the first time the dependence of in vivo resting spore formation of P. nouryi upon the concentration of infective inoculum. A hypothesis is thus proposed that some sort of biochemical signals may exist in the host,pathogen interaction so that the fungal pathogen perceives the signals for prompt response to forthcoming host-density changes by either producing conidia for infecting available hosts or forming resting spores for surviving host absence in situ. [source] Cloning and characterisation of a prenyltransferase from the aphid Myzus persicae with potential involvement in alarm pheromone biosynthesisINSECT MOLECULAR BIOLOGY, Issue 4 2008M. J. Lewis Abstract The majority of aphid species release an alarm pheromone with the most common component being the sesquiterpene (E)-,-farnesene, sometimes accompanied by other sesquiterpenes or monoterpenes. The genes/enzymes involved in the production of these compounds have not been identified in aphids although some components of isoprenoid biosynthesis have been identified in other insect species. Here we report the cloning, expression and characterisation of a prenyltransferase from the aphid Myzus persicae which can act as a farnesyl pyrophosphate synthase or a geranyl pyrophosphate synthase to produce both sesquiterpenes and monoterpenes and hence could be responsible for the biosynthesis of the observed components of the alarm pheromones. In addition, the enzyme can utilise geranyl pyrophosphate to produce farnesyl pyrophosphate showing that the synthesis of the latter involves the sequential condensation of isoprenyl pyrophosphate units. [source] Effect of the antimicrobial peptide indolicidin on the green peach aphid Myzus persicae (Sulzer)JOURNAL OF APPLIED ENTOMOLOGY, Issue 2 2007R. R. Le-Feuvre Abstract:, The green-peach aphid, Myzus persicae (Sulzer) (Hem., Aphididae), is a major agricultural pest of a wide range of host plants, causing damage by feeding and indirectly by transmitting viruses. In this study we tested the effect of the antimicrobial peptide indolicidin on M. persicae survival and on its essential bacterial endosymbionts. Artificial diet bioassays showed a significant dose-dependent lethal response of indolicidin on M. persicae survival (LD50 of 209 ± 60 ,g/ml). Histological analysis of indolicidin-treated aphids revealed a lower number of distorted mycetocytes, whereas control aphids showed abundant number of rounded and filled mycetocytes. These results suggest that aphid survival could be affected via reduction of its endosymbionts. Thus, aphid control based on antimicrobial substances against endosymbionts could be a promising strategy that needs to be further explored. [source] Organic farming-compatible insecticides against the aphid Myzus persicae (Sulzer) in peach orchardsJOURNAL OF APPLIED ENTOMOLOGY, Issue 3 2006C. Karagounis Abstract:, Three products allowed in organic farming (kaolin, mineral oil and insecticidal soap) as alternatives to chemical insecticides, were evaluated for the control of Myzus persicae (Sulzer) in a peach orchard. Their efficacy was compared with the neonicotinoid imidacloprid and an untreated control. The experiment was replicated for 2 years (2003 and 2004). The products were applied once in May every year and aphid infestation was recorded three to four times post-treatment. In 2004, the effect of the products on the predatory coccinellid species was also recorded. In 2003, all four products showed good control with average Abbott's efficiency ranging from 80% to 88%. In the next year, however, the products were less effective and only imidacloprid and kaolin reduced aphid population significantly compared with the untreated control, with an average Abbott's efficiency of 62% and 31%, respectively. This reduced efficiency was attributed to high rainfall occurring post-treatment. Regarding the effects on beneficial coccinellids, only imidacloprid and mineral oil reduced their numbers after application. The results showed that the three alternative products and especially kaolin are promising for aphid control in peach orchards. Kaolin has also low side-effects on beneficials and it could be used in organic peach orchards. [source] Temporal dynamics of genotypic diversity reveal strong clonal selection in the aphid Myzus persicaeJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 1 2006C. VORBURGER Abstract Parthenogenetic organisms often harbour substantial genotypic diversity. This diversity may be the result of recurrent formations of new clones, or it may be maintained by environmental heterogeneity acting on ecological differences among clones. In aphids, both processes may be important because obligate and cyclical parthenogens can form mixed populations. Using microsatellites, I analysed the temporal dynamics of clonal diversity in such a population of the aphid Myzus persicae over a 1-year period. The frequency distribution of clonal genotypes was very skewed, with many rare and few common clones. The relative frequencies of common clones underwent strong and rapid changes indicative of intense clonal selection. Differences in their host associations suggest that these shifts may partly be caused by changes in the abundance of annual host plants. Other selective factors of potential importance are also discussed. New, sexually produced genotypes made a minor contribution to clonal diversity, consistent with the observed heterozygote excess characteristic of predominantly asexual populations in M. persicae. [source] Behavioural responses of the seven-spot ladybird Coccinella septempunctata to plant headspace chemicals collected from four crop Brassicas and Arabidopsis thaliana, infested with Myzus persicaeAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 4 2008R. D. Girling Abstract 1,Insects using olfactory stimuli to forage for prey/hosts are proposed to encounter a ,reliability,detectability problem', where the usability of a stimulus depends on its reliability as an indicator of herbivore presence and its detectability. 2,We investigated this theory using the responses of female seven-spot ladybirds Coccinella septempunctata (Coleoptera: Coccinellidae) to plant headspace chemicals collected from the peach-potato aphid Myzus persicae and four commercially available Brassica cultivars; Brassica rapa L. cultivar ,turnip purple top', Brassica juncea L. cultivar ,red giant mustard', Brassica napus L. cultivar ,Apex', Brassica napus L. cultivar ,Courage' and Arabidopsis thaliana. For each cultivar/species, responses to plants that were undamaged, previously infested by M. persicae and infested with M. persicae, were investigated using dual-choice Petri dish bioassays and circular arenas. 3,There was no evidence that ladybirds responded to headspace chemicals from aphids alone. Ladybirds significantly preferred headspace chemicals from B. napus cv. Apex that were undamaged compared with those from plants infested with aphids. For the other four species/cultivars, there was a consistent trend of the predators being recorded more often in the half of the Petri dish containing plant headspace chemicals from previously damaged and infested plants compared with those from undamaged ones. Furthermore, the mean distance ladybirds walked to reach aphid-infested A. thaliana was significantly shorter than to reach undamaged plants. These results suggest that aphid-induced plant chemicals could act as an arrestment or possibly an attractant stimulus to C. septempunctata. However, it is also possible that C. septempunctata could have been responding to aphid products, such as honeydew, transferred to the previously damaged and infested plants. 4,The results provide evidence to support the ,reliability,detectability' theory and suggest that the effectiveness of C. septempunctata as a natural enemy of aphids may be strongly affected by which species and cultivar of Brassica are being grown. [source] Spatial and temporal dynamics of Myzus persicae clones in fields and suction trapsAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 2 2008Louise Kasprowicz Abstract 1,The population of peach-potato aphid Myzus persicae in Scotland is comprised almost entirely of long-term asexual clones. 2,Over a ten year period, M. persicae from Scottish fields and suction traps were analysed with six microsatellite markers. 3,Out of 1497 individuals analysed, 14 clones (denoted A,N) comprised over 98% of the collection. 4,Some clones were particularly abundant but most clones had a widespread distribution on all available plants. 5,Clones E and L had distinct features in their distributions as clone L was geographically totally restricted to the north east of Scotland and clone E showed a marked preference for brassica crops. 6,Clones E and L provide direct evidence of a role for local adaptations in the distribution of M. persicae clones. [source] Evaluation of the biocontrol potential of various Metarhizium isolates against green peach aphid Myzus persicae (Homoptera: Aphididae)PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 6 2010Le-Tian Shan Abstract BACKGROUND: Twenty-three isolates of Metarhizium anisopliae (Metschnikof) Sorokin and M. acridum (Driver & Milner) JF Bischoff, Rehner & Humber from non-aphid host insects around the globe were evaluated for their aphid biocontrol potential, which is not well known. RESULTS: The apterous adults of green peach aphid Myzus persicae (Sulzer) were exposed to the fungal sprays of 11.5, 99 and 1179 conidia mm,2 and blank control in three leaf-dish bioassays. All the tested isolates except one were proven to be infective to the aphid species at 21 ± 1 °C and 14:10 h light:dark photoperiod, causing corrected mortalities of 10.1,95.3% at the high spore concentration. The data from ten isolates causing > 50% mortality at the high concentration were found to fit a time,concentration,mortality model well, yielding parameters for the estimates of their LC50 and LT50 that vary with post-spray time and spore concentration respectively. Four isolates of M. anisopliae (ARSEF 759, 4132, 2080 and 576) had LC50 values of 44,80 conidia mm,2 on day 8 and LT50 values of 4.9,6.8 days at 100 conidia mm,2, with 91,98% of the killed aphids being well mycotised after death. CONCLUSION: The Metarhizium infectivity to M. persicae differs greatly among the tested isolates. The four mentioned isolates with desired virulence and sporulation potential are excellent candidates for microbial control of aphids. Copyright © 2010 Society of Chemical Industry [source] Insecticidal spider venom toxin fused to snowdrop lectin is toxic to the peach-potato aphid, Myzus persicae (Hemiptera: Aphididae) and the rice brown planthopper, Nilaparvata lugens (Hemiptera: Delphacidae)PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 1 2006Rachel E Down Abstract The SFI1/GNA fusion protein, comprising of snowdrop lectin (Galanthus nivalis agglutinin, GNA) fused to an insecticidal spider venom neurotoxin (Segestria florentina toxin 1, SFI1) was tested for toxicity against the rice brown planthopper Nilaparvata lugens (Stål) and the peach-potato aphid Myzus persicae (Sulzer) by incorporation into artificial diets. Significant effects on the mortality of N. lugens were observed, with 100% of the insects fed on the SFI1/GNA fusion protein diet dead by day 7. The survival of the aphid M. persicae was also reduced when fed on the SFI1/GNA fusion protein. After 14 days, only 49% of the aphids that were fed on the fusion protein were still alive compared with approximately 90% of the aphids fed on the control diet or on diet containing GNA only. The SFI1/GNA fusion protein also slowed the development of M. persicae, and the reproductive capacity of the aphids fed on the SFI1/GNA fusion protein was severely reduced. The ability of GNA to act as a carrier protein, and deliver the SFI1 neurotoxin to the haemolymph of N. lugens, following oral ingestion, was investigated. The successful delivery of intact SFI1/GNA fusion protein to the haemolymph of these insects was shown by western blotting. Haemolymph taken from the insects that were fed on the fusion protein contained two GNA-immunoreactive proteins of molecular weights corresponding to GNA and to the SFI1/GNA fusion protein. © 2005 British Crown Copyright. Published for SCI by John Wiley & Sons, Ltd. [source] Clonal composition of the peach-potato aphid Myzus persicae (Homoptera: Aphididae) in France and Scotland: Comparative analysis with IGS fingerprinting and microsatellite markersANNALS OF APPLIED BIOLOGY, Issue 3 2003B FENTON Summary Fourteen colonies of the peach-potato aphid, Myzus persicae, were taken either from French peach trees or weeds in 2001. Thirty five apomictic parthenogenetic lineages (APLs) were established. Ribosomal DNA intergenic spacer (IGS) fingerprinting was used to characterise these and 28 fingerprints were duly obtained. Those lineages with different fingerprints were considered different genotypes and those with the same fingerprint as the same. The genetic identity of APLs was further tested using four microsatellite loci. APLs that differed by IGS fingerprint had distinct microsatellite allele combinations and those that had the same IGS fingerprint had the same microsatellite allele combinations. The results confirmed that IGS types corresponded to different aphid genotypes. Independent APLs with identical IGS and microsatellite genotype were therefore considered different representatives of the same clone. APLs from M. persicae found on Scottish crops in 1995, 1996 and 2001, as well as a long-term laboratory line were also examined by the same methods. Their IGS fingerprints were similar or identical suggesting that they all belonged to the same clone. Microsatellite markers also suggested that these lineages were derived from a single clone. Some field lineages exhibited slight modifications to their IGS fingerprints confirming that the IGS evolves more rapidly than these microsatellite alleles. Thus, IGS will continue to provide a useful marker for aphid fieldwork. [source] Diversity of detoxification pathways of ingested ecdysteroids among phytophagous insectsARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 2 2007Kacem Rharrabe Abstract The metabolic pathways of ingested ecdysteroids have been investigated in three insect species, the aphid Myzus persicae and two Lepidoptera, Plodia interpunctella and Ostrinia nubilalis. M. persicae produces mainly a 22-glucoside conjugate, whereas P. interpunctella eliminates a mixture of 20E and its 3-oxo and 3-epi derivatives, both in free form and as conjugates with various fatty acids. O. nubilalis only produces fatty acyl ester conjugates. These data point out the great diversity of detoxification mechanisms used by phytophagous insects in order to overcome the potential harmful effects of ecdysteroids present in their food. Arch. Insect Biochem. Physiol. 65:65,73, 2007. © 2007 Wiley-Liss, Inc. [source] Insecticide resistance in the aphid Myzus persicae (Sulzer): chromosome location and epigenetic effects on esterase gene expression in clonal lineagesBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2003LINDA M. FIELD Insecticide treatment of the aphid Myzus persicae (Sulzer) has led to the evolution of several insecticide resistance mechanisms, including the detoxification of insecticides by elevated esterases. This results from amplification of one of two closely related esterase genes (E4 or FE4) with up to 80 copies in the most resistant aphids. The amplified E4 genes are at a single site linked to a chromosomal translocation and resistance can be unstable. Individuals within a clone lose their elevated esterase and resistant phenotype, a good example of ,clonal variation'. This loss of esterase is accompanied by a loss of the corresponding mRNA but the amplified genes are retained with no detectable sequence differences. However, the expressed E4 genes contain 5-methylcytosine, which is lost at the same time as the genes are turned off. This is in direct contrast with vertebrate genes where DNA methylation causes gene silencing, but it does suggest that the resistant phenotype in M. persicae is under epigenetic control. One hypothesis is that 5-methylcytosine in E4 genes facilitates expression by preventing the production of incorrectly initiated transcripts. It is interesting that we have never detected silencing of amplified FE4 genes, possibly because they are at multiple loci and therefore less likely to be subject to synchronous control. © 2003 The Linnean Society of London. Biological Journal of the Linnean Society, 2003, 79, 107,113. [source] Antixenosis phloem-based resistance to aphids: is it the rule?ECOLOGICAL ENTOMOLOGY, Issue 4 2010VINCENT LE ROUX 1. The concept of plant defence syndrome states that plant species growing in similar biotic or abiotic constraints should have convergent defensive traits. This article is a first step to test the prediction of this concept, by conducting experiments on wild Solanum species (or accessions) that originated from the Andes. The nature and the tissue localisation of the resistance of five wild Solanum species known to be resistant against the aphids Myzus persicae and Macrosiphum euphorbiae were determined by olfactometry and electrical penetration graph experiments. 2. Volatile organic compounds may contribute to wild Solanum resistance, depending on Solanum accessions and aphid species. Volatiles of S. bukasovii and S. stoloniferum PI 275248 were not attractive to M. persicae, whereas S. bukasovii was repulsive to M. euphorbiae. In contrast, volatiles of S. stoloniferum PI 275248 were attractive for M. euphorbiae. 3. Some wild Solanum species presented a generalised resistance in all plant tissues, so as for S. bukasovii and S. stoloniferum PI 275248 against M. persicae. However, except for S. bukasovii which was susceptible to M. euphorbiae, all tested Solanum species presented a phloem-based antixenosis resistance against the two aphid species. 4. A review of articles focused on the nature of resistance of wild Solanum species against aphids corroborated with our results, i.e. a phloem-based antixenosis resistance against aphids is the rule concerning the system aphids,wild Solanum species. [source] | |||||||||||||||||||||||||