1,721,016 research outputs found
Modalità di svernamento di Glycaspis brimblecombei (Hemiptera:Psyllidae) nelle aree di recente introduzione in Italia
No full textNel periodo giugno-agosto del 2010, in diverse località di Campania, Basilicata e Lazio, su Eucalyptus camaldulensis, e su ibridi della stessa essenza vegetale, sono state individuate infestazioni più o meno severe di Glycaspis brimblecombei Moore (Hemiptera: Psyllidae), la psilla dal follicolo bianco ceroso dell’Eucalipto rosso (Laudonia & Garonna, 2010; Garonna et al, 2011). Non è noto come la specie sia giunta sul territorio nazionale, ma è ipotizzabile una sua diffusione passiva. La psilla, originaria dell’Australia, è nota con il nome comune di “ red gum lerp psyllid” e ciò in riferimento al nome comune dell’ E.camaldulensis (red gum) e alla produzione dei caratteristici “lerps”, follicoli di protezione di colore bianco, secreti dagli stadi preimmaginali e costituiti da cera e melata cristallizzata. Il termine "lerps", in lingua aborigena, sta ad indicare sostanze di sapore dolciastro di diversa origine, generalmente essudati prodotti da vegetali o insetti, utilizzate comunemente come alimento. G. brimblecombei è considerata invasiva ed estremamente dannosa in California, Florida, Argentina, Cile, Mauritius e Madagascar. Le prime segnalazioni per l’Europa e l’area Paleartica riguardano la Penisola Iberica. Nel primo anno di presenza della specie in Italia, sono stati condotti studi sulla modalità di svernamento della specie nelle aree di nuova introduzione. In particolare sono stati condotti campionamenti settimanali in un parco urbano di Napoli, e, a partire dal mese di gennaio, anche nel Lazio in località Casaccia e Bracciano. I dati raccolti hanno permesso di verificare la composizione delle popolazioni della psilla in termini di prevalenza e presenza degli stadi preimmaginali e degli adulti di G. brimblecombei. Nel medesimo periodo sono stati inoltre valutati la presenza e l’impatto dell’antagonismo naturale ad opera di entomofagi autoctoni. I risultati della ricerca indicano che G. brimblecombe sverna in tutti gli stadi continuando anche nel periodo invernale la propria attività di riproduzione. L’attività degli antagonisti è, nel periodo considerato, poco consistente e limitata a predazioni da parte di generalisti, mentre non è stata rilevata alcuna attività di entomoparassitoidi. Tra i nemici naturali conosciuti di G. brimblecombei, vi è Psyllaephagus bliteus Riek (Hymenoptera: Encyrtidae), che è stato con successo introdotto dall’Australia nelle aree di neo-colonizzazione neartiche
Catture di Ophelimus eucalypti (Gahan) (Hym.: Eulophidae) imenottero galligeno dell�Eucalyptus con trappole cromotropiche e prove di controllo.
No full textFirst record of the bronze bug, Thaumastocoris peregrinus Carpintero & Dellapé (Heteroptera: Thaumastocoridae), a new exotic pest of Eucalyptus trees in Italy
Full text linkIn September 2011, the bronze bug Thaumastocoris peregrinus Carpintero & Dellapé (Heteroptera: Thaumastocoridae) was detected in Italy infesting Eucalyptus spp. in several urban and rural sites of the Latium region (Italy) (Laudonia & Sasso, 2012). This is the first record of a member of the family Thaumastocoridae from the European and Mediterranean region. Until recently, the Australian group of Thaumastocoridae was considered rare (Cassis et al., 1999), but over the past 10 years, T. peregrinus has rapidly established as a severe pest on 13 species of Eucalyptus and Corymbia citriodora subsp. citriodora in Australia (Noack & Rose, 2007; Noack et al. 2009), and spread to South America (Martinez-Crosa, 2008; Carpintero & Dellapé 2006; Noack & Coviella, 2006; Wilcken et al., 2010; Savaris et al., 2011) and South Africa (Jacobs & Neser, 2005; Giliomee, 2011).
The adult of T. peregrinus is characterized by a strongly dorso-ventrally compressed and elongate body between 2-3.5 mm in length, a broad head, pedicellate eyes, and elongate conspicuous mandibular plates which are curved and broad on the outer margin (Noack et al., 2011). The body is light brown with darker areas. The male genital capsule is asymmetrical. The eggs are dark, oval, with a sculptured chorion and a round operculum, on average 0.5 mm long and 0.2 mm wide. The crawlers and young nymphs are essentially orange, with black spots on the thorax and first abdominal segments. A detailed description of T. peregrinus has been published by Carpintero and Dellapé (2006), and more recently a re-description of the species has been published by Noack et al. (2011).
Infested Eucalyptus trees show leaf silvering, ranging from chlorosis to bronzing. Heavy infestations cause leaves to become red/brown and defoliation occurs. These symptoms are particularly serious and evident on E. grandis, while the prevalent symptoms on other Eucalyptus species are silver leaves. The bronze bugs are also considered as a nuisance, having been reported to ‘sting’ people in urban parks, playgrounds, etc. (Jacobs & Neser, 2005).
In Southern Europe (Italy, Spain and Portugal), Eucalyptus species are probably the only large scale and economically successful short rotation tree plantations also used for industrial purposes, such as production of sawn wood, wood pulp, charcoal and biomass fuel. The nectar from flowers of some eucalypts produces high-quality of monofloral honey. T. peregrinus is a serious pest of Eucalyptus species in the Southern Hemisphere and could become a forest and urban pest in Southern Europe and in the Mediterranean Basin
Phenology and distribution of Italian populations of Thaumastocoris peregrinus Carpintero and Dellap? (Heteroptera: Thaumastocoridae)
No full textSummary: Phenology and distribution of Italian populations of Thaumastocoris peregrinus Carpintero and Dellapé (Heteroptera: Thaumastocoridae). Thaumastocoris peregrinus Carpintero & Dellapè (Heteroptera: Thaumastocoridae) was detected for the first time in Italy in September 2011, on several Eucalyptus species and hybrids. This pest, native of Australia, was the first species of the family Thaumastocoridae found in Europe. In this paper we report data on its current distribution in Italy, where the species is present in Lazio, Campania and Tuscany. Phenological studies allowed to detect the presence of eggs, preimaginal stages and peaks of the flight of the adults. No diapausing stage were detected
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
Alfred North Whitehead, Procès et réalité. Essai de cosmologie. Traduit de l'anglais par D. Charles, M. Elie, M. Fuchs, J.-L. Gautero, D. Janicaud, R. Sasso, A. Villani
No full textBouckaert Bertrand. Alfred North Whitehead, Procès et réalité. Essai de cosmologie. Traduit de l'anglais par D. Charles, M. Elie, M. Fuchs, J.-L. Gautero, D. Janicaud, R. Sasso, A. Villani. In: Revue Philosophique de Louvain. Quatrième série, tome 93, n°3, 1995. pp. 447-449
Alfred North Whitehead, Procès et réalité. Essai de cosmologie. Traduit de l'anglais par D. Charles, M. Elie, M. Fuchs, J.-L. Gautero, D. Janicaud, R. Sasso, A. Villani
No full textBouckaert Bertrand. Alfred North Whitehead, Procès et réalité. Essai de cosmologie. Traduit de l'anglais par D. Charles, M. Elie, M. Fuchs, J.-L. Gautero, D. Janicaud, R. Sasso, A. Villani. In: Revue Philosophique de Louvain. Quatrième série, tome 93, n°3, 1995. pp. 447-449
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