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Native and introduced parasitoids in the biocontrol of Dryocosmus kuriphilus in Veneto (Italy)
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Performance of Trichopria drosophilae (Hymenoptera: Diapriidae), a Generalist Parasitoid of Drosophila suzukii (Diptera: Drosophilidae), at Low Temperature
Full text linkSurvival and parasitism activity of Trichopria drosophilae Perkins adults, a cosmopolitan parasitoid of Drosophila spp., were studied under laboratory conditions using five constant temperatures at the lower range known for this enemy, from 4 to 20°C in 4°C increments. Drosophila suzukii Matsumura, an invasive pest of small fruits, was used as a host. Commercially available adult parasitoids were provided with 1) food and D. suzukii pupae; 2) food and no D. suzukii pupae; 3) no food and no pupae. The results show that adult females of T. drosophilae lived longer than males, and both generally benefitted from food supply. The highest level of survival was observed between 8 and 12°C for fed insects, irrespective of whether they were offered host pupae or not. The absence of food led to the highest mortality, but the parasitoid demonstrated considerably resistance to prolonged starvation. Successful parasitism increased steadily with temperature and reached the highest value at 20°C. Conversely, D. suzukii emergence rate was high after exposure of pupae to parasitoids at 4°C, while pupal mortality increased strongly with temperature until 12°C. The findings indicate that T. drosophilae is well adapted to the relatively cold conditions experienced in early spring and in autumn or at high elevations, when the host pupae could be largely available. The long lifespan of the adults and the ability to parasitize the host at low temperature make T. drosophilae potentially useful for the biocontrol of D. suzukii
Efficient transmission of an introduced pathogen via an ancient insect-fungus association.
No full textCitizen science at school increases awareness of biological invasions and contributes to the detection of exotic ambrosia beetles
Full text linkThe serious and growing threat posed by biological invasions to biodiversity and livelihoods means that public engagement in dealing with problems of invasive alien species is ever more urgent and necessary hence a citizen science experiment was carried out in north-eastern Italy. The study aimed i) to raise awareness of invasive alien species threatening trees and forests, and ii) to perform monitoring activities of a group of wood borers as an example, involving teachers and students (aged 11 to 18) of high schools. Students and teachers were given background knowledge and trained about the protocol for collecting data in schoolyards/grounds. Native (Anisandrus dispar (Fabricius, 1792), Xyleborinus saxesenii (Ratzeburg, 1837)) and exotic ambrosia beetles (Anisandrus maiche Kurentsov, Cnestus mutilatus (Blandford), Xylosandrus crassiusculus (Motschulsky, 1866), Xylosandrus germanus (Blandford, 1894)) were used as the target species, as they could be easily detected through accessible and low-cost traps requiring limited effort. The traps were exposed for 24 hours weekly between March and June 2021. The experiment also aimed to strengthen public involvement, connecting environmental education and experiential outdoor learning. The mutual collaboration resulted in a wider knowledge of the potential impact of exotic species. It also led to new geographical citizen-science records of two alien ambrosia beetles considered to be quarantine pests by the European Union: C. mutilatus, new for the European part of the EPPO (European and Mediterranean Plant Protection Organization) region, and A. maiche, which was previously found only in Eastern European EPPO member countries
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
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