1,720,961 research outputs found
The Red gum lerp psyllid Glycaspis brimblecombei Moore: a monitoring approach
No full textGlycaspis brimblecombei Moore (Hem.: Aphalaridae) is an invasive species for the Mediterranean area on
several species of Eucalyptus, especially E. camaldulensis, the River Red Gum, hence its common name. It
was reported in Italy, in Campania, Lazio and Basilicata in June 2010, and is spreading quickly in most of the
country. Infestations of G. brimblecombei are most easily recognized by the very peculiar conical white
coverings (lerps) secreted by the preimaginal stages. Damages consist in lymph subtraction and leaf drop,
honeydew and lerps also cause inconveniences in urban environment. The Red gum lerp psyllid is considered
a serious pest that may cause severe defoliation and tree mortality on some Eucalyptus spp. The specific
parasitoid Psyllaephagus bliteus Riek (Hym.: Encyrtidae), was accidentally introduced in Italy in 2011 and
recorded in Campania since 2012. The monitoring was carried out from the first year of introduction of the
psyllid and continued after the introduction of the parasitoid. Initially only the population dynamics of the
psyllid was monitored assessing the average number of psillyd for leaf in different time ranges with similar
temperature values. In order to determine the active parasitism, after the parasitoid introduction, with the
dissections of the psyllid it was obtained the parasitization dynamic. A model, based on the classical Volterra
predator-pray equations, was also developed in the first year of introduction to follow the host-parasitoid
dynamics in relation of the environmental condition.The study proposes an accurate method for population
monitoring of the psyllid and its parasitoid. Observations prove that both species are well established in the
new environmental condition and overwinter in all stages. Moreover, the use of different values of the host
growth rate in the Lotka-Volterra model describes the overall trend of the unstable dynamics that
characterise the parasitoid-host interaction, although the specific oscillations are not observed
Geographical distribution of the Bronze bug Thaumastocoris peregrinus Carpintero et Dellapé in Campania
No full textIn Europe, with 1.3 million hectares, Eucalyptus spp. are the most important dicotyledonous plantation and
the only large scale and economically successful short rotation tree plantations. Many of the plantations are
grown for commercial purposes as a source of renewable energy resources, pulp and paper industry, wood
products, oils, tannins, nectar and honey. In addition the eucalypts are used to induce carbon sequestration,
phytoremediation via salinity control, phytoremediation via rhizofiltering, as windbreaks, to stabilize the
banks of rivers and canals and, like ornamental, along the streets and urban parks. This resource is seriously
threatened by alien invasive pests and pathogens. Most of these movements have been relatively recent, like
for the Bronze bug Thaumastocoris peregrinus Carpintero et Dellapé (Heteroptera: Thaumastocoridae).
Overthe past 10 years, the Bronze bug has rapidly established as a severe pest on several species of eucalypts
and Corymbia citriodora subsp. Citriodora in the world. Infested eucalypts trees show leaf silvering, ranging
from chlorosis to bronzing. Heavy infestations cause leaves to become red/brown, after which defoliation
occurs. On September 2011, heavy infestations of T. peregrinus, first record of a member of the family
Thaumastocoridae from Europe and Mediterranean Region, were found on several Eucalyptus species in the
Italian region of Lazio. Since that time, the species has spread along the coastal area and in the neighboring
region of Campania, where highly susceptible species of eucalypts are common (e.g. E. camaldulensis). A
meticulous monitoring action has been carried out since first year of introduction in Campania. The
dispersion and distribution of the bronze bug increases rapidly and the occurrence of this invasive species was
recorded in many areas of the region. The localities were geo-referenced and illustrated by info- graphic
Andamento delle popolazioni e fenologia di Glycaspis brimblecombei Moore (Hemiptera: Aphalaridae), Psilla del follicolo bianco ceroso dell’Eucalipto rosso
No full textSeasonal occurrence and adaptation of the exotic Glycaspis brimblecombei Moore (Hemiptera: Aphalaridae) in Italy
No full textAlien insects usually adapt their phenology and their needs to the environment into which they are introduced. During 2010, the red gum lerp psyllid, Glycaspis brimblecombei, was accidentally introduced into Italy, becoming an invasive pest of Eucalyptus L'Hér. Eucalypts are very common in Italy as ornamental and forest species. The seasonal adaptation of the psyllid was studied at three field sites. G. brimblecombei showed a seasonal population dynamic, suggesting that many generations occur during the year and the species overwinters in all stages without diapause. The population size in the new area of colonization is affected by low winter temperatures, but also by high temperatures in the absence of rainfall. In Lazio, the specific parasitoid Psyllaephagus bliteus was collected for the first time
Fenologia e distribuzione di Thaumastocoris peregrinus Carpintero & Dellapè (Heteroptera: Thaumastocoridae) su Eucalyptus spp. in ambiente urbano.
No full textThaumastocoris peregrinus è specie invasiva originaria dell’Australia in rapida diffusione nei Paesi del Mediterraneo. I dati sono stai raccolti presso il parco Urbano della Mostra d’Oltremare di Napoli. I rilievi relativi alla fenologia di T. peregrinus, al fine di determinare l’andamento annuale delle popolazioni, hanno consentito, posti a confronto con i dati climatici, l’individuazione di tre distinte fasi di evoluzione delle infestazioni e fra queste, di particolare interesse è la crescita esponenziale che si verifica dopo i caldi estivi e che raggiunge il suo massimo nel mese di ottobre per poi calare rapidamente. Per una migliore comprensione degli andamenti, sono state utilizzate le medie e le varianze delle popolazioni di adulti, stadi giovanili e uova vitali. La distribuzione di T. peregrinus sull’ospite è stata messa in relazione all’orientamento magnetico terrestre. La maggiore presenza del fitofago si è riscontrata, con una differenza statisticamente significativa, sul lato della pianta esposta a Sud, Sud-Est e per tutti gli stadi di sviluppo indipendentemente dai dati climatici. La valutazione della distribuzione verticale della popolazione ha individuato la predominanza di individui nella zona medio-alta confermata anche dallo studio delle distribuzioni di adulti, stadi giovanili e uova per foglia. La descrizione delle caratteristiche di disposizione della specie nello spazio, ha una notevole importanza ecologica per la scelta dei metodi di campionamento, la scelta degli indici per l’analisi dei dati e per consentire eventualmente una misura della popolazione utilizzando l’algoritmo del vicino più prossimo. La descrizione qualitativa dello stato in cui è una data popolazione consente inoltre, l’utilizzazione dei modelli di distribuzione matematici. Infine, nel corso dei campionamenti effettuati non si è mai riscontrata la presenza di antagonisti naturali specifici e di predatori autoctoni generalisti. L’assenza del controllo naturale, unitamente all’ampio range termico in cui il T. peregrinus è in grado di sopravvivere, spiegano la rapida espansione delle aree interessate dalla presenza del fitofago. Alla luce dei dati sin qui ottenuti, in considerazione delle conseguenze letali che un'infestazione massiccia comporta, alla mancanza di possibilità di controllo chimico su vasta scala e certamente non praticabile in ambiente urbano, si sta valutando la possibilità di introdurre, dall’Australia, il Mymaridae ooparassitoide specifico, Cleruchoides noackae
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
Interactive Visualization Modeling with CoDe: An Application to Entomological Data
No full textA taxonomy of typical interaction techniques is proposed in [1], where seven categories of information visualizations provided by commercial systems are considered. This framework gives an initial foundation toward a deeper understanding of interaction in Information Visualization, helping discussion and evaluation of interaction techniques. In this chapter we propose a methodology for the specification and design of complex interactive visualizations as an extension of the graphic language CoDe [2]. Based on the seven categories introduced in [1], we add new interaction operators to CoDe, to enable a visualization designer to specify multiple perspectives of a data set, without losing the underlying mental map of the considered information. The new version of CoDe allows to manage some interaction techniques which are difficult to classify and do not quite fit into any of the categories above. Some applications of the proposed methodology to design interactive visualizations of entomological data are provided as a case study
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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