1,720,988 research outputs found
Termites in the vines: Kalotermes flavicollis is one of the main pests of Sherry vineyards in Andalusia, Spain
No full textSherry vineyards, located in Andalusia (SW Spain) yield important registered designation of origin wines. These vines are affected by important sanitary problems caused by the termite Kalotermes flavicollis (Isoptera: Kalotermitidae) and the fungus Eutypa lata. A detailed investigation was performed during 15 months in nine districts of the Sherry area on differently aged vines of the “Palomino fino” variety. Samples were collected twice a month, cutting randomly selected vines into six sections, which were examined to detect the living status and the presence of arthropods (K. flavicollis, Reticulitermes lucifugus, ants) and fungi (Eutypa dieback disease, wood fungi). The results showed that among the 44% unhealthy vines, always aged more than 15 years old, K. flavicollis, found in almost 84% of cases, and often in contemporary presence with dead vine areas, represented the major pest of sherry vineyards, followed by Eutypa symptoms (14%), whereas Reticulitermes lucifugus, ants and wood fungi were found only sporadically. The characterization of the infestations, their trend over the seasons and their location in different sectors of the vines will be shown and discussed
Spatial and temporal features and social composition of vine-infesting colonies of Kalotermes flavicollis in Sherry vineyards (Spain)
No full textIn Andalusia (SW Spain), Kalotermes flavicollis (Isoptera: Kalotermitidae) is considered one of the major pests of Sherry vineyards. Colonies of this termite progressively debilitate the vines, causing the sequential loss of the arms and resulting in serious economic losses, since Sherry vineyards yield important registered designation of origin wines. A detailed investigation aimed to analyse the patterns of infestation of this termite, was performed during 15 months in nine districts of the Sherry area on differently aged vines of the “Palomino fino” variety. Samples were collected twice a month, cutting randomly selected vines into six sections, which were carefully opened to pick up all eggs and individuals. Collected termites were then recognized, separated and counted according to the developmental stage or caste (eggs, larval and nymphal stages, pseudoergates, soldiers, alates, reproductives). The results allowed to get the social composition of vine attacking colonies and to detect, for different castes and developmental stages, significant differences in the spatial distribution inside the vine and in the numerical trends over the seasons. The biological meaning of these findings will be discussed
Effects of spurge flax (Daphne gnidium L., Thymelaeaceae) extracts on the development and mortality of the elm leaf beetle (Coleoptera: Chrysomelidae)
No full textSpurge flax (Daphne gnidium L., Thymelaeaceae) is an evergreen shrub typical of the Mediterranean flora. It has been traditionally used for centuries in Spain as a control agent of invertebrate pests of crops and cattle. Previuos bioassays performed in our laboratory demonstrated that leaves and ethanolic extracts of D. gnidium showed antifeedant activity on pest species belonging to the orders Heteroptera, Isoptera, Lepidoptera and Coleoptera. The elm leaf beetle, Galerucella luteola Müller (Coleoptera, Chrysomelidae), in Spain represents one of the most important pests of elms (Ulmus spp.) in both river bank forests and urban areas, being responsible for partial or total defoliation of the tree tops. In order to study the effects of spurge flax on G. luteola, different doses of an ethanolic extract of D. gnidium were added to the natural diet (elm leaves) of young larvae. During the development, weight changes, phase durations and mortality rates of each stage were recorded. Results showed that the addition of spurge flax extract to the diet of G. luteola induced: a) a significant increase in the duration of the larval period; b) greater mortality rates for all stages; c) weight reduction of individuals of all stages, including imagoes
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
Predictive model for the emergence of Xylotrechus arvicola (Coleoptera: Cerambycidae) in La Rioja vineyards (Spain)
No full textXylotrechus arvicola (Coleoptera, Cerambycidae) (Olivier) is a polyphagous borer which attacks different woody species in natural habitats in Spain. This coleopteran is also becoming a real impacting pest in several Spanish wine producing territories. Infested vines show adult exit holes, rachitic shoots, a higher incidence of wood fungal diseases and fragility. At the beginning of the 1990s, a heavy increase of infestation was observed in La Rioja vineyards, the only Qualified Guarantee of Origin Region (A.O.C.) in Spain. Due to the endophytic development of the larvae of X. arvicola, adults are the designated target for the integrated management. Therefore, the aim of the present paper was to study the flight period of the pest and to calculate the value of degree-days for the emergence of both sexes from data collected in the field during 2003-2008 in a Tempranillo cultivar in Tirgo (La Rioja). Adult emergences occurred from the end of May to mid-August and a certain degree of protandry was detected. The predictive models obtained for each year fit a sinusoidal curve in all cases, except for males in 2004, when the adjustment was polynomial. The obtained correlation coefficients were considerably high, as the value 0.99 was exceeded in 72% of the cases. These results obtained in La Rioja vineyards suggest that control strategies aimed at the reduction of the adult population of X. arvicola in the view of the integrated management, should be performed between mid-June and the end of July
Hábitats, estado sanitario y caracterización enolólogica de la vid silvestre [Vitis vinifera L. subespecie sylvestris (Gmelin) Hegi] en Cerdeña (Insula vini)
No full textSe ha realizado una prospección del recurso fitogenético vid silvestre en diferentes zonas de la isla de Cerdeña, durante la etapa de floración, para comprobar su carácter dioico. Se ha realizado una evaluación sobre fitófagos y parásitos de las parras y un estudio botánico sobre la vegetación mediterránea de sus entornos. El estudio sanitario revela que el ácaro de la erinosis y el mildiu son las principales especies parásitas de los órganos aéreos de las parras. No se han detectado síntomas causados por filoxera, nematodos y hongos de la podredumbre en las raíces.
Para evaluar el potencial enológico de las parras femeninas, con la uva procedente de una población de vid salvaje en el Cerdeña del Sur se ha realizado una microvinificación, con la que se ha obtenido vino tinto de 13o v/v, con bastante intensidad de color y pH bajo
Monitorización de la infestación de Xylotrechus arvicola (Olivier) (Coleoptera, Cerambycidae) en un viñedo de La Rioja Alta
No full textDesde 1997 a 2015 se ha realizado un muestreo bianual en una parcela de 4.000 cepas de la
variedad Tempranillo situada en la localidad de Tirgo (La Rioja). En una muestra de 160 cepas, georeferenciadas por mediadas GPS, se han contabilizado el número de orificios de salida de los imagos en troncos y brazas, así como la aparición de síntomas asociados a la presencia de hongos de madera en los pámpanos.Con los datos obtenidos se han generado 10 mapas sobre los niveles crecientes de infestación/infección de dichos parásitos en la
parcela. Éstos muestran que tanto el inicio de los síntomas causados por el perforador, como de la presencia de hongos de madera, se produjeron en la zona central de la misma, donde se concentra una mayor incidencia
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
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