1,720,958 research outputs found
Standardization and criticism of sampling procedures using sticky card traps: Monitoring sap-sucking insect pests and anagrus atomus inhabiting european vineyards
No full textColoured sticky card traps are widely used for sampling and control of sap-sucking insect pests. In European vineyards they are used for monitoring leafhoppers [i.e., Empoasca vitis (Gothe), Zygina rhamni Ferrari, Scaphoideus titanus Ball], the vine thrips Drepanothrips reuteri Uzel and the leafhopper egg parasitoid Anagrus atomus (L.). A study was conducted to establish the trap factors that influence captures of these insects (i.e., size, inclination, exposure days, colour, position within canopy and side orien-tation). The total captures of grapevine leafhoppers increased as trap size increased, without a significant decline in captures relative to unit area. All leafhopper species were more attracted by vertical traps than horizontal traps, and in the latter case, E. vitis and Z. rhamni were mainly captured on the underside of the trap, while S. titanus on the upper side. For all leafhoppers and D. reuteri, efficiency decreased with the number of days the traps remained in the field. Yellow was a colour preferred by all in-sects, with Z. rhamni showing a strong preference for lighter yellows. S. titanus was also captured by red traps and A. atomus by colourless ones. Z. rhamni and S. titanus showed a preference for traps placed in shady positions, whereas E. vitis and D. reuteri preferred traps in sunny positions. E. vitis and D. reuteri preferred trap sides exposed to sunlight in the late afternoon and early morning, respectively. Our results were compared with the literature and discussed in relation to the feeding preference and behaviour of the different species
Side Effects of Kaolin and Bunch-Zone Leaf Removal on Generalist Predators in Vineyards
Full text linkIn vineyards, kaolin application and bunch-zone leaf removal (LR) were effective in the control of leafhoppers and Lobesia botrana, but their side effects on generalist predators are still poorly understood. In north-eastern Italian vineyards, the impact of kaolin and LR on species and functional diversity of spiders, as well as the abundance of spiders and generalist predatory insects, was assessed in one vineyard for two consecutive years and in two vineyards for one year. The ecological indices of the spider community were never influenced by kaolin and only in one case were they influenced by LR. At the spider family level, kaolin reduced the abundance of Araneidae, Oxypidae and Salticidae, but only in single cases. In single cases, kaolin reduced the amount of Orius sp. anthocorids and increased that of Scymninae coccinellids, whereas LR increased the amount of Aeolothrips sp. The moderate use of kaolin and the application of LR had negligible and inconsistent impacts on generalist predatory arthropods in vineyards and were therefore, compatible with IPM strategies
Side effects of sulfur dust on the European grapevine moth Lobesia botrana and the predatory mite Kampimodromus aberrans in vineyards
Full text linkTo reduce the impact of synthetic insecticides on human health and the environment, eco-friendly alternatives must be investigated. Knowledge of the side effects on pests and natural enemies of natural products applied to vineyards is very useful. Sulfur dust, which is used in vineyards to control powdery mildew, is investigated in laboratory and field bioassays for its effects on Lobesia botrana egg laying, egg hatching, and larval settlement. In field trials, the efficacy of sulfur dust against the two L. botrana carpophagous generations is compared with that of Bacillus thuringiensis and kaolin, and its side effects on the phytoseiid mite Kampimodromus aberrans are evaluated. In the bioassays, sulfur dust reduced female survival by 43%, egg laying by around 80%, egg hatching by 10%, and larval settlement by 55%. In field trials, sulfur dust caused a significant decrease in the number of L. botrana larval nests of both generations, even though the efficacy was lower than that of B. thuringiensis. No negative effects of sulfur dust on the predatory mite population density was observed. On the basis of these results, in the context of Integrated Pest Management strategies in vineyards, the activity of sulfur dust against L. botrana could be exploited by timing its application to the beginning of egg laying
Side Effects of Kaolin and Bunch-Zone Leaf Removal on Predatory Mite Populations (Acari: Phytoseiidae) Occurring in Vineyards
No full textThe effects of kaolin and bunch-zone leaf removal on populations of predatory mites Kampimodromus aberrans
(Oudemans) and Typhlodromus pyri Scheuten were assessed in the context of four trials (2015–2016)
carried out against Lobesia botrana (Denis and Schiffermüller) (Lepidoptera: Tortricidae) in vineyards located
in north-eastern Italy. Laboratory experiments were performed to evaluate the effects of kaolin on the survival
and fecundity of K. aberrans and T. pyri populations originating from the same grape-growing area. In field
trials, kaolin caused a gradual decrease in population density levels of both phytoseiid species (with the maximum
reduction ranging from 49 to 91%) with a complete population recovery in the next spring. In laboratory
experiments, kaolin was moderately harmful to both species, reducing their fecundity significantly (around
60%). Bunch-zone leaf removal determined lower phytoseiid populations in all trials, but this effect was significant
only for K. aberrans in one of them. A limited use of kaolin and the adoption of bunch-zone leaf removal
did not irreversibly affect phytoseiid populations in vineyards and thus can be considered compatible with IPM
strategies
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
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