Development of field-applicable tests for rapid and sensitive detection of Candidatus Phytoplasma oryzae.

Napier grass Stunt Disease (NSD) is a severe disease of Napier grass (Pennisetum purpureum) in Eastern Africa, caused by the leafhopper-transmitted bacterium Candidatus Phytoplasma oryzae. The pathogen severely impairs the growth of Napier grass, the major fodder for dairy cattle in Eastern Africa. NSD is associated with biomass losses of up to 70% of infected plants.

A New Phytosanitary Method to Reduce the Ascospore Potential of Venturia inaequalis.

Ascospores of Venturia inaequalis, released from pseudothecia in overwintered, infected apple leaves, serve as the primary inoculum for apple scab. In this study, we tested a new sanitation strategy to reduce ascospore inoculum under orchard conditions over three overwintering periods. After leaf fall, nutrient media containing different concentrations of degraded casein or a yeast extract from Saccharomyces cerivisiae were applied to leaf litter infected with apple scab.

Wolbachia in Parasitoids Attacking Native European and Introduced Eastern Cherry Fruit Flies in Europe.

The eastern cherry fruit fly, Rhagoletis cingulata Loew (Diptera: Tephritidae), is an economically important pest of cherries in North America. In 1983 it was first reported in Europe where it shares its ecological niche with the native European cherry fruit fly, Rhagoletis cerasi L. (Diptera: Tephritidae).

Detection, Identification, and Characterization of Phytoplasmas Infecting Apple and Pear Trees in Belarus.

In Samochvalovichi, Belarus, apple and pear tree root samples were examined for the presence of phytoplasmas using a universal 16S rDNA-based PCR assay. Out of 27 tested apple trees, 23 were found to be infected by 'Candidatus Phytoplasma mali' and 46 out of 58 pear trees were positive for the presence of 'Ca. P.

Validation of Individual-Based Markov-Like Stochastic Process Model of Insect Behavior and a "Virtual Farm" Concept for Enhancement of Site-Specific IPM.

The paper reports application of a Markov-like stochastic process agent-based model and a "virtual farm" concept for enhancement of site-specific Integrated Pest Management. Conceptually, the model represents a "bottom-up ethological" approach and emulates behavior of the "primary IPM actors"-large cohorts of individual insects-within seasonally changing mosaics of spatiotemporally complex faming landscape, under the challenge of the local IPM actions. Algorithms of the proprietary PESTonFARM model were adjusted to reflect behavior and ecology of R.

Protection of Vine Plants against Esca Disease by Breathable Electrospun Antifungal Nonwovens.

The harmful Esca disease in vine plants caused by wood-inhabiting fungi including Phaeomoniella chlamydospora (Pch) is spreading all across the world. This disease leads to poor vine crops and a slow decline or to a sudden dieback of the vine plants. The pruning wounds of vine plants are the main entry point for Pch.

Detection, Identification, and Significance of Phytoplasmas in Wild Grasses in East Africa.

Plant-pathogenic phytoplasmas found in wild grasses in East Africa could pose a serious threat to the cultivation of Napier grass, Pennisetum purpureum, the most important livestock fodder in the region. To asses this threat, leaves from plants of 33 grass species were sampled from Mbita, Bungoma, and Busia districts in western Kenya; Tarime district in northern Tanzania; and Busia and Bugiri districts in the eastern Uganda to determine which species host phytoplasmas, the identity of the phytoplasmas, and their relationship with disease symptoms. Phytoplasmas were detected using universal primers based on conserved phytoplasma-specific 16S rDNA sequences from 11 grass species collected.

Assessing the Barley Genome Zipper and Genomic Resources for Breeding Purposes.

The aim of this study was to estimate the accuracy and convergence of newly developed barley (Hordeum vulgare L.) genomic resources, primarily genome zipper (GZ) and population sequencing (POPSEQ), at the genome-wide level and to assess their usefulness in applied barley breeding by analyzing seven known loci. Comparison of barley GZ and POPSEQ maps to a newly developed consensus genetic map constructed with data from 13 individual linkage maps yielded an accuracy of 97.

Differentiation of 'Candidatus Phytoplasma cynodontis' Based on 16S rRNA and groEL Genes and Identification of a New Subgroup, 16SrXIV-C.

'Candidatus Phytoplasma cynodontis' is widespread in bermudagrass and has only been found in monocotyledonous plants. Molecular studies carried out on strains collected in Italy, Serbia, and Albania enabled verification of molecular variability in the 16S ribosomal RNA (rRNA) gene. Based on restriction fragment length polymorphism and sequence analyses, the strains from Serbia were clearly differentiated from all others and assigned to a new ribosomal DNA (rDNA) subgroup designated as 16SrXIV-C.

Unifying bacteria from decaying wood with various ubiquitous Gibbsiella species as G. acetica sp. nov. based on nucleotide sequence similarities and their acetic acid secretion.

Bacteria were isolated from necrotic apple and pear tree tissue and from dead wood in Germany and Austria as well as from pear tree exudate in China. They were selected for growth at 37 °C, screened for levan production and then characterized as Gram-negative, facultatively anaerobic rods. Nucleotide sequences from 16S rRNA genes, the housekeeping genes dnaJ, gyrB, recA and rpoB alignments, BLAST searches and phenotypic data confirmed by MALDI-TOF analysis showed that these bacteria belong to the genus Gibbsiella and resembled strains isolated from diseased oaks in Britain and Spain.

Survival relative to new and ancestral host plants, phytoplasma infection, and genetic constitution in host races of a polyphagous insect disease vector.

Dissemination of vectorborne diseases depends strongly on the vector's host range and the pathogen's reservoir range. Because vectors interact with pathogens, the direction and strength of a vector's host shift is vital for understanding epidemiology and is embedded in the framework of ecological specialization. This study investigates survival in host-race evolution of a polyphagous insect disease vector, Hyalesthes obsoletus, whether survival is related to the direction of the host shift (from field bindweed to stinging nettle), the interaction with plant-specific strains of obligate vectored pathogens/symbionts (stolbur phytoplasma), and whether survival is related to genetic differentiation between the host races.

Molecular differentiation of Pantoea stewartii subsp. indologenes from subspecies stewartii and identification of new isolates from maize seeds.

Aims: Assays to detect Pantoea stewartii from maize seeds should include differentiation of P. stewartii subsp. stewartii and P.

Methoxypyrazine composition of Coccinellidae-tainted Riesling and Pinot noir wine from Germany.

Background: Harmonia axyridis (multicolored Asian ladybeetle) and Coccinella septempunctata (seven-spot ladybeetle) (Coccinellidae) are found in many wine regions in Europe and the Americas, where they are responsible for a pronounced wine fault known as 'ladybug taint' when incorporated with grapes during harvest operations. Methoxypyrazines have been proposed in the literature as the compounds responsible for the taint. This study sought to expand on this identification and also determine the effectiveness of heating Coccinellidae-affected grape must prior to fermentation as a possible remedial intervention.

Analysis of expressed genes of the bacterium 'Candidatus phytoplasma Mali' highlights key features of virulence and metabolism.

'Candidatus Phytoplasma mali' is a phytopathogenic bacterium of the family Acholeplasmataceae assigned to the class Mollicutes. This causative agent of the apple proliferation colonizes in Malus domestica the sieve tubes of the plant phloem resulting in a range of symptoms such as witches'--broom formation, reduced vigor and affecting size and quality of the crop. The disease is responsible for strong economical losses in Europe.

Identification and genetics of 6-thioguanine secreted by Erwinia species and its interference with the growth of other bacteria.

We identified a compound in culture supernatants of Erwinia species, such as Erwinia amylovora, E. pyrifoliae, E. billingiae, E.

Bait spray for control of European cherry fruit fly: an appraisal based on semi-field and field studies.

Background: The European cherry fruit fly, Rhagoletis cerasi, is the major insect pest of sweet and tart cherries. Its management is becoming increasingly difficult in many countries as formerly effective but broad-spectrum insecticides are removed from the market. With the objective of identifying suitable and environmentally safe alternatives, we investigated bait sprays containing two families of plant-derived insecticides: azadirachtins (NeemAzal-T(®) and NeemAzal-T/S(®) ) and pyrethrins (Spruzit Neu(®) ).

Molecular analyses of Erwinia amylovora strains isolated in Russia, Poland, Slovenia and Austria describing further spread of fire blight in Europe.

Fire blight, a bacteriosis of apple and pear, was assayed with molecular tools to associate its origin in Russia, Slovenia and south-eastern Austria with neighboring countries. The identification of all investigated strains was confirmed by MALDI-TOF mass spectroscopy except one. Independent isolation was verified by the level of amylovoran synthesis and by the number of short sequence DNA repeats in plasmid pEA29.

Gene-for-gene relationship in the host-pathogen system Malus × robusta 5-Erwinia amylovora.

Fire blight is a destructive bacterial disease caused by Erwinia amylovora affecting plants in the family Rosaceae, including apple. Host resistance to fire blight is present mainly in accessions of Malus spp. and is thought to be quantitative in this pathosystem.

Influence of diet on fecundity, immune defense and content of 2-isopropyl-3-methoxypyrazine in Harmonia axyridis Pallas.

Food type can affect all functional aspects of an insect's life. We investigated the effects of different diet regimes on life history parameters of the ladybird beetle Harmonia axyridis. Furthermore, we tested the importance of elytral color, sex, and diet on chemical and immune defense in this species.

'Candidatus Phytoplasma convolvuli', a new phytoplasma taxon associated with bindweed yellows in four European countries.

Plants of Convolvulus arvensis exhibiting symptoms of undersized leaves, shoot proliferation and yellowing, collectively defined as bindweed yellows, were sampled in different regions of Europe and assessed for phytoplasma infection by PCR amplification using phytoplasma universal rRNA operon primer pairs. Positive results were obtained for all diseased plants. RFLP analysis of amplicons comprising the16S rRNA gene alone or the16S rRNA gene and 16-23S intergenic spacer region indicated that the detected phytoplasmas were distinguishable from all other previously described rRNA gene sequences.

Molecular characterization and taxonomy of grapevine leafroll-associated virus 7.

The complete nucleotide sequence of an Albanian isolate of grapevine leafroll-associated virus 7 (GLRaV-7-Alb) was determined. The viral genome consists of 16,404 nucleotides and has nine open reading frames (ORFs) that potentially encode proteins, most of which are typical for members of the family Closteroviridae. Only the 25-kDa (ORF8) and 27-kDa (ORF9) proteins had no apparent similarity to other viral proteins in the sequence databases.

Detection of Erwinia species from the apple and pear flora by mass spectroscopy of whole cells and with novel PCR primers.

Aims: To detect the apple and pear pathogens Erwinia amylovora and Erwinia pyrifoliae as well as the related epiphytes Erwinia tasmaniensis and Erwinia billingiae, we created novel PCR primers and also applied them to a series of other plant-associated bacteria as control. To facilitate fast diagnosis, we used matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS).

Methods And Results: The PCR primers were deduced from the pstS-glmS regions, which can include the gene for levansucrase, and also from regions encoding capsular polysaccharide synthesis.

Offspring production and self-superparasitism in the solitary ectoparasitoid Spalangia cameroni (Hymenoptera: Pteromalidae) in relation to host abundance.

Parasitoid fitness strongly depends on the availability and quality of hosts, which provide all resources required for larval development. Several factors, such as host size and previous parasitation, may affect host quality. Because self-superparasitism induces competition among a female's offspring, it should only occur if there is an imperfect recognition of self-parasitized hosts or if there is a fitness advantage to self-superparasitism.

Hydrodynamics of raindrop impact stimulate ascospore discharge of Venturia inaequalis.

Ascospores of Venturia inaequalis are released from leaves following the impact of raindrops during rain events. Atmospheric humidity or moisture from dew does not have an inductive effect on ascospore release. The hydrodynamics of raindrop impact on leaf surfaces was investigated.

A well protected intruder: the effective antimicrobial defense of the invasive ladybird Harmonia axyridis.

The harlequin ladybird Harmonia axyridis (Coleoptera: Coccinellidae) is a polyphagous predatory beetle native to Central and Eastern Asia. Since 2007 it has established all over Central Europe. In order to elucidate which defense strategy is responsible for its high resistance to diseases, we tested hemolymph as well as eleven main components of the headspace of H.