35 research outputs found

    Occupancy of the territory by Lymantria dispar (L.) (Lepidoptera Erebidae) egg masses as a predictive index of damage

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    In Sardinia (Italy) the population abundance of the defoliator gypsy moth Lymantria dispar (L.) (Lepidoptera Erebidae) has been regularly sampled for over thirty years by counts of egg masses. This monitoring activity allows annual identification of the areas with the highest abundance of infestation in order to define the areas to be subjected to phytosanitary treatments and thus to confine the damage caused by gypsy moth defoliation. However, the identification of areas to be treated have been defined exclusively according to the experience gained over the years by the operators. To overcome the limitation of this empirical approach we have developed an objective method supporting decision making based on the relationship between the percentage of infested sites and the intensity of defoliation. For this purpose the radius of annual gypsy moth expansion was estimated in a cork oak district: the estimated value was ca. 6 km per year. This value was used to calculate the percentage of sites occupied by at least 1 egg mass within that radius. A generalized linear model was used to evaluate the statistical significance of the relationship between percentage of occupied sites and presence of damage. According to what we know from literature a monitoring site was considered damaged when defoliation level of foliage was greater than 50%. We then used the historical series of data to calculate the probability that a defoliation event would occur according to the estimated model. The logit model confirmed the validity of the predictor with respect to the presence of damage, with a general accuracy greater than 90%. The results suggest a revision of the sampling protocol used thus far, which requires a particularly costly and prolonged sampling effort. The method described herein should allow easier identification of forest areas exposed to damage and timelier planning of control interventions

    Les anthologies surrĂ©alistes : l’élaboration collective d’un genre littĂ©raire hybride

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    Published for the first time in 1940 the AndrĂ© Breton’s Anthology of black humor inaugurates the great season of surrealist anthologies, which will last until late 60s. The use of the traditional form of the modern anthology by the Surrealists, does not involve into a complete acceptance of its rules, already codified since the end of the 19th century, but rather a deformation of its textual structure and of its objectives, producing a literary genre with particular characteristics. The surrealist anthology, such as those realized by AndrĂ© Breton, Paul Éluard, Louis Aragon and Benjamin PĂ©ret, represent an hybrid literary object with structural elements in common with the dictionary, the glossary, the anthology and the catalogue. The surrealist literary collections represent both a different approach to the history of literature and an expression of surrealist poetics

    Evaluation of different Bacillus thuringiensis sv kurstaki formulations against Lymantria dispar and Malacosoma neustria larvae infesting Quercus suber trees

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    Lepidopteran defoliators such as Lymantria dispar and Malacosoma neustria represent a major concern for cork oak forest, especially during population outbreaks. To contain their infestations over large areas, the use of entomopathogenic microorganisms such as Bacillus thuringiensis serovar kurstaki (Btk) is one of the available option. However, the features of the microbial control agent formulations represent a key factor for the success of application programs. The results of two years efficacy trials with different formulations of Btk, conducted in 2012 and 2013 in a cork oak forest in North-Western Sardinia, are reported. In the first year, trials were carried out on a M. neustria population, while in the second year a mixed population of L. dispar and M. neustria was involved. Trials included two formulations of Btk strain EG 2348 (RapaxÂź and Rapax Experimental) in comparison with two other commercial formulations (Foray 48BÂź and DelfinÂź). Both formulations of Btk strain EG 2348 proved to be effective in controlling the two pest species, showing a forest protection potential comparable to that of the reference products, Foray 48BÂź and DelfinÂź, containing spores and insecticidal Cry proteins of strains HD-1 and SA-11, respectively. Also the defoliation levels were significantly higher in untreated control trees than in treated ones

    When a threatened species becomes a threat: a key to reading the Habitats Directive based on occurrence and distribution of Cerambyx cerdo L. in Mediterranean urban and peri-urban areas

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    Abstract Cerambyx cerdo is a large saproxylic species included in the Annex IV of the European Habitats Directive as a 'priority species'. Although C. cerdo populations have shown a significant decline in size and distribution in central and northern European forests, in the Mediterranean basin it is often considered as a pest in urban and peri‐urban areas. Based on European legislations currently in use, we propose a simplified decision‐making flowchart that should be followed regarding the adoption of different control measures against severe C. cerdo infestations

    POPULATION DYNAMICS AND SEASONAL ABUNDANCE OF THAUMASTOCORISPEREGRINUSIN EUCALYPTUSPLANTATIONS IN SARDINIA (ITALY)

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    Thaumastocoris peregrinusis a eucalyptus pest native to Australia. It is currently the only species belonging to theThaumastocoridae family in Europe. In Italy, it was reported for the first time in Latium in 2011, whereas in Sardinia itwas detected in January 2015 on a Eucalyptus camaldulensis plantation located in the south of the island. Our researchteam carried out a monitoring program for two-years in order to verify its geographical distribution, the main periods ofinfestation, the flight peaks of the adults and to also detect the presence of unhatched eggs on leaves. During the firstyear, the occurrence of adults of T. peregrinuswas verified by yellow sticky traps placed in twelve areas distributedthroughout the island where Eucalyptus plantations were located. In the second year, the population dynamics and theoccurrence of eggs on leaves were evaluated only in three representative study areas, already included in the previousmonitoring program, located in the north, centre and south of the island, respectively. Field surveys showed thepresence of T. peregrinusin all the monitored locations. The highest adult population was observed from late summer toinitial autumn, with a significant increase in adults caught by yellow sticky traps from August, which reached its peakin September and gradually decreased in the following months. The presence of eggs of T. peregrinuson leaves fromJune to December also indicates that the insect is currently well established in the region

    PRELIMINARY RESULTS ON THE SPATIO-TEMPORAL VARIABILITYOF GLYCASPIS BRIMBLECOMBEI(HEMIPTERA PSYLLIDAE) POPULATIONSFROM A THREE-YEAR MONITORING PROGRAM IN SARDINIA (ITALY)

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    The red gum lerp psyllid Glycaspis brimblecombeiis an invasive insect species worldwide. Prolonged attacksby this psyllid may cause both direct and indirect damages to Eucalyptustrees, such as plant weakening, developmentalreductions and phylloptosis, resulting in death within 2-3 years. After the first report in Campania (Italy) in 2010 onEucalyptus camaldulensis trees, it quickly spread to all surrounding central-southern regions of Italy. In Sardinia, G.brimblecombeiwas first recorded in 2011, and is currently found throughout the island. From 2013 to 2015 amonitoring program was carried out in 11 locations throughout Sardinia in order to estimate the density pattern of bothits adults and preimaginal stages, as well as the general population trend of G. brimblecombeiover the years. Ananalysis of G. brimblecombei population abundance showed an almost stable level of infestation over the years, and aseasonal pattern with a population peak in the summer. However, an earlier peak of population abundance was detectedin 2015 compared to the previous years. A spatial heterogeneity of the level of infestation was observed throughout theisland, highlighting the potential effects of environmental conditions in regulating the populations of both G.brimblecombeiand its natural enemies

    Long-term monitoring and microbiological control programs against lepidopteran defoliators in Sardinian cork oak forests (Italy)

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    The gypsy moth, Lymantria dispar (L.), and the tent caterpillar, Malacosoma neustrium (L.), are the main cork oak, Quercus suber L., pests in the Mediterranean area and cause complete defoliation in large forest districts. In order to control infestations, large scale aerial applications of insecticides based on Bacillus thuringiensis subsp. kurstaki (Btk) have been carried out in Sardinia (Italy) since 2001. This paper evaluated the frequency of outbreaks in forest districts with varying homogeneity of land use, forest areas annually exposed to defoliation and the effectiveness of control programs based on Btk insecticide applications.The volume of areas annually exposed to defoliation depends on forest homogeneity, as infestations are more frequent in cork oak areas with a lower than 25% canopy cover rate. The microbiological control programme efficiently protected cork oaks from lepidopteran defoliators and caused an overall annual mean mortality of over 60%, with maximum rates of 89.9 and 98.0% for L. dispar and M. neustrium, respectively. To date, approximately 180,000 hectares of cork oak forests have been protected by spraying Btk-based insecticides

    Using Species Distribution Models (SDMs) to Estimate the Suitability of European Mediterranean Non-Native Area for the Establishment of Toumeyella Parvicornis (Hemiptera: Coccidae)

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    The pine tortoise scale, Toumeyella parvicornis, is an insect native to the Nearctic region that is able to infest several Pinus species. It can cause weakening, defoliation and, at high infestation levels, tree death. After its first report in Italy in 2015, the pest spread rapidly over the surrounding areas and was reported in France in 2021. Due to the threat that this pest poses to pine trees, the suitability of European Mediterranean basin areas for T. parvicornis at different spatial scales was estimated by constructing species distribution models (SDMs) using bioclimatic variables. Our results showed that several coastal areas of the Mediterranean basin area could be suitable for T. parvicornis. Based on performance assessment, all the SDMs tested provided a good representation of the suitability of European Mediterranean non-native area for T. parvicornis at different spatial scales. In particular, most of the areas with a medium or high level of suitability corresponded to the geographical range of distribution of different Pinus spp. in Europe. Predicting the suitability of European Mediterranean areas for T. parvicornis provides a fundamental tool for early detection and management of the spread of this pest in Europe.N.D.S. is funded by the Lazio Region (Agriculture Department) and the Università degli Studi della Tuscia (Italy). The research was carried out in the frame of the Italian MIUR (Ministry for Education, University and Research) initiative ‘Department of Excellence’ (Law 232/2016). L.R. and R.M. are funded by MUR (Italian Ministry of University and Research) in the framework of the European Social Funding REACT-EU—National Program for Research and Innovation 2014–2020

    Assessing the response of ground-dwelling beetles communities to different land-uses in Mediterranea cork oak systems

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    In our study, we assessed the response of beetles communities at low taxonomical resolution to different Mediterranean cork oak land-use systems. Spatial variation of dung-beetles communities was also analyzed because of their potential role as ecological indicators in grazed areas
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