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Biological control of Hyalesthes obsoletus Signoret, the main insect vector of ‘Candidatus Phytoplasma solani’, using entomopathogenic nematodes and fungi
No full textHyalesthes obsoletus Signoret is a univoltine, polyphagous species completing its complex life cycle, including the nymph subterranean cryptic stage, on herbaceous wild plants in European countries. In vineyards, it occasionally transmits ‘Candidatus Phytoplasma solani’, an obligate parasitic bacterium associated with Bois noir disease of grapevine, from its preferred host plants to grapevine. As no effective control measures targeting phytoplasmas are available, main strategies to manage the disease is based on the vector control. In the case of H. obsoletus, insecticide treatments on grapevine canopy are completely inefficient due to its life cycle. Consequently, the control of this planthopper focuses on its nymphs living on the host plant roots. In the present study, the control activity of entomopathogenic nematodes (EPNs; (Steinernema carpocapsae, S. feltiae, Heterorhabditis bacteriophora) and fungi (EPFs; Beauveria bassiana, Metarhizium anisopliae, Paecilomyces fumosoroseus, Lecanicillium muscarium) against H. obsoletus nymphs and adults were evaluated by laboratory bioassays and semi-field trials. Statistical analyses demonstrated that the majority of the examined EPNs and EPFs are able to control H. obsoletus nymphs and adults, exhibiting a range of effectiveness. In all the conducted trials, S. carpocapsae and P. fumosoroseus were found as the most effective biocontrol agents among EPNs and EPFs, respectively. Interestingly, considering their ability to colonize the soil after their inoculation, EPNs and EPFs can reduce the H. obsoletus population density for long time. Ecological competency and conditions that can impede or enhance the EPNs and EPFs performance should be investigated to optimize their performance in field conditions
Control of Hyalesthes obsoletus nymphs based on chemical weeding and insecticides applied on Urtica dioica
Full text linkBois noir is a grapevine yellows disease associated with Candidatus Phytoplasma solani and transmitted to grapevines by means of the planthopper Hyalesthes obsoletus Signoret (Homoptera, Cixiidae). The overwintering nymphs of the vector acquire the phytoplasma feeding on roots of herbaceous plants, including Urtica dioica L. (stinging nettle). In German and Italian vineyards the possibility to control the H. obsoletus nymphs feeding on stinging nettle roots using chemical weeding and insecticides was investigated. In particular, the effect of herbicides, applied in autumn and in different spring timings, and neonicotinoid insecticides on vector adult emergence was evaluated. Trials conducted to control nettle with glyphosate or a mixture of glyphosate+flazasulfuron significantly reduced the density of emerging adult vectors. The efficacy of herbicides was highest when they were applied in autumn or in early spring with the nymphs not older than the fourth instar. Herbicides applied too close to the beginning of the emergence of adults reduced numbers only during the late part of the planthopper flight-period. Although neonicotinoid insecticides applied in early spring gave efficacy comparable to herbicides, their use is not advisable for the negative side effects on non-target arthropods (e.g. honeybees). Overall, the combination of cultural practices and accurately timed applications of selective herbicides might help to refine the current Integrated Pest Management recommendations for controlling nettle, H. obsoletus and consequently bois noir
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
IDENTIFICATION AND GROUPING OF MYCOPLASMALIKE ORGANISMS ASSOCIATED WITH GRAPEVINE YELLOWS AND CLOVER PHYLLODY DISEASES BASED ON IMMUNOLOGICAL AND MOLECULAR ANALYSEE
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