Survival and Feeding Rates of Four Aphid Species (Hemiptera: Aphididae) on Various Sucrose Concentrations in Diets.

Different concentrations of sucrose were used to investigate how survival and feeding was affected in four species of aphids (Hemiptera: Aphididae). Seven sucrose concentrations were evaluated in feeding chambers fitted with parafilm membranes and infested with nymphs of Aphis glycines Matsumura, Diuraphis noxia Kurdjumov, Myzus persicae Sulzer, or Schizaphis graminum Rondani at 25 °C and a photoperiod of 14:10 (L:D) h. Survival on each diet was recorded 1, 3, 5, 7, 9, and 11 d.

The genome of Diuraphis noxia, a global aphid pest of small grains.

Background: The Russian wheat aphid, Diuraphis noxia Kurdjumov, is one of the most important pests of small grains throughout the temperate regions of the world. This phytotoxic aphid causes severe systemic damage symptoms in wheat, barley, and other small grains as a direct result of the salivary proteins it injects into the plant while feeding.

Results: We sequenced and de novo assembled the genome of D.

Potential transmission of Pantoea spp. and Serratia marcescens (Enterobacteriales: Enterobacteriaceae) to plants by Lygus hesperus (Hemiptera: Miridae).

Lygus hesperus Knight (Hemiptera: Miridae) is a key agricultural pest in the western United States. In a recent study, proteins from Pantoea ananatis and Serratia marcescens (Enterobacteriales: Enterobacteriaceae) were identified in diet that was stylet probed and fed on by L. hesperus adults.

Variation in the salivary proteomes of differentially virulent greenbug (Schizaphis graminum Rondani) biotypes.

Unlabelled: Greenbug (Schizaphis graminum Rondani) biotypes are classified by their differential virulence to wheat, barley, and sorghum varieties possessing greenbug resistance genes. Virulent greenbug biotypes exert phytotoxic effects upon their hosts during feeding, directly inducing physiological and metabolic alterations and accompanying foliar damage. Comparative analyses of the salivary proteomes of four differentially virulent greenbug biotypes C, E, G, and H showed significant proteomic divergence between biotypes.

Response of Russian wheat aphid resistance in wheat and barley to four Diuraphis (Hemiptera: Aphididae) species.

Three Diuraphis species, Diuraphis frequens (Walker), Diuraphis mexicana (McVicar Baker), and Diuraphis tritici (Gillette), were known to exist in the United States before the 1986 appearance of the Russian wheat aphid, Diuraphis noxia Kurdjumov. The Russian wheat aphid soon became a significant pest of wheat although other endemic Diuraphis species were known to infest wheat. Wheat and barley entries resistant and susceptible to Russian wheat aphid biotype 2 were evaluated against all four Diuraphis species to determine their host interrelationships.

Proteomic analysis of secreted saliva from Russian wheat aphid (Diuraphis noxia Kurd.) biotypes that differ in virulence to wheat.

Diuraphis noxia, Russian Wheat Aphid (RWA), biotypes are classified by their differential virulence to wheat varieties containing resistance genes. RWA salivary proteins, unlike those of most aphid species, cause foliar damage and physiological alterations in plants. A comparative proteomic analysis of secreted saliva from four differentially virulent RWA biotypes identified thirty-four individual proteins.

Transgene constructs lacking transcription termination signal induce efficient silencing of endogenous targets in Arabidopsis.

Efficient gene silencing tools are extremely important for genomics and biotechnology applications. A number of aberrant RNA species induce silencing of homologous genes; however, only the inverted repeat RNA is widely utilized for targeted gene silencing in plants. Development of additional silencing constructs would not only provide an alternative technology for single targets, it may also serve as a simpler platform for multi-target silencing.

Transgene-induced silencing of Arabidopsis phytochrome A gene via exonic methylation.

Transgene-induced promoter or enhancer methylation clearly retards gene activity. While exonic methylation of genes is frequently observed in the RNAi process, only sporadic evidence has demonstrated its definitive role in gene suppression. Here, we report the isolation of a transcriptionally suppressed epi-allele of the Arabidopsis thaliana phytochrome A gene (PHYA) termed phyA' that shows methylation only in symmetric CG sites resident in exonic regions.